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Emil Kirkegaard left a short commentary on John Skoyles’ 1999 paper Human Evolution Expanded Brains to Increase Expertise Capacity, not IQ, in which Emil writes in his article Evolution and imperfect mediators:
If we condense the argument, it becomes a little clearer:
John Skoyles (1999) [Condensed argument from Emil; paragraph 2] Brain expansion causes problems. Thus, whatever selected for increased brain size must have offered compensating benefits. People can have below average size brains yet exhibit normal intelligence. Thus, the compensating benefit offered by large brains is unlikely to be intelligence. Why should evolution have increased brain size with its associated problems for something smaller sized brains could have without expansion?
I merely edited out the unnecessary parts. Now try substituting some other trait, say fighting ability and some mediator of it.
Muscle size increases causes problems. Thus, whatever selected for increased muscle size must have offered compensating benefits. People can have below average size muscles yet exhibit normal fighting ability. Thus, the compensating benefit offered by large muscles is unlikely to be fighting ability. Why should evolution have increased muscle size with its associated problems for something smaller sized muscles could have without increase?
See the issue? This argument works for any imperfect physical underpinning of a trait, which is to say, basically all of them. Longer legs didn’t evolve for running well for some people with short legs run well. Bigger/stronger hears didn’t evolve for better cardio, because some people smaller/weaker hearts have good cardio. Longer arms didn’t evolve for fighting because some short armed people fight well. Darker skin didn’t evolve as a protection against sun exposure for some relative light skinned people don’t get skin cancer or sunburns. Larger eyes didn’t evolve for seeing better for some people with smaller eyes see well. Bigger ears… Bigger noses… Stronger hands… …
I don’t agree. Our brains sap about 20 percent of our daily energy needs while being 2 percent of our overall body mass whereas, in other primates, their brains cost about 9 percent of their daily energy needs (Fonseca-Azevedo and Herculano-Houzel, 2012).
In regards to Emil’s counterarguments, I’ll address them one by one:
Long legs: People with longer legs were better runners and could escape from predators and chase prey. People with shorter legs were killed.
Bigger/stronger hearts: Those with a larger heart (sans cardiomegaly) could run for longer distance (remember, we are distance runners; Carrier, 1984; Skoyles and Sagan, 2002; Bramble and Lieberman, 2004; Mattson, 2012) and so long legs and bigger/stronger hearts tie in with each other.
Long arms: This, again, goes back to our morphology in Africa. Long limbs are more conducive to heat dissipation (Lieberman, 2015). So those who had the right body plan for distance running could survive better during our evolutionary history.
Dark skin: A light-skinned person who spends enough time without protection in a tropical climate will develop skin cancer. (It is hypothesized that skin cancer is what caused the evolution of dark skin; Greaves, 2014, though this was contested by Jablonksi and Chaplin, 2014.)
Large eyes: Bigger eyes don’t mean better eyesight in comparison to smaller ones.
All in all, the brain size argument is 100 percent different from these arguments: large brains come with large problems. Further, there is evidence (which will be reviewed below) that people can live long, normal lives with half of their brain missing
The brain-size/IQ puzzle
The oft-repeated wisdom is that our brains evolved to such a large size so we could become more intelligent. And looking at when our brains began to increase (starting with erectus, which had to do with the advent of cooking/fire use), we can see that that’s when our modern body plan appeared. We can ascertain this by looking at Nariokotome boy, an erectus that lived about 1.6 mya.
Further, in regards to brain size, there was a man named Daniel Lyon. What was so extraordinary about this man is that, at the time of his death, had a brain that weighed 1.5 pounds (see Wilder, 1911)! Skoyles and Sagan (2002: 239) write:
Upon examination, anatomists could find no difference between it [Lyon’s brain] and other human brains apart from its size with one exception: The part of his brain attached to the brainstem, the cerebellum, was near normal size. Thus, the total size of Lyon’s cerebral hemisphere was smaller than would be suggested by a total brain weight of 1.5 lb. We do not know how bright he was—being a watchman is not particularly intellectually demanding—but he clearly was not retarded. A pound and a half brain may not be enough to manage a career as an attorney, a professor of theology, or a composer, but it was sufficient to let Lyon survive for 20 years in New York City.
Skoyles and Sagan (2002) review numerous lines of evidence of individuals with small brains/people with severe TBI living full lives, even having IQs in the average/above average range. They write (pg 238):
You would think that cutting out one-half of people’s brains would kill them, or at least leave them vegetables needing care for the rest of their lives. But it does not. Consider this striking story. A boy starts having seizures at 10 years of age when his right cerebral hemisphere atrophies. By the time he is 12, the left side of his body is paralyzed. When he is 19, surgeons decide to operate and remove the right side of his brain, as it is causing gits in his intact left one. You might think this would lower his IQ or leave him severely retarded, but no. His IQ shoots up 14 points, to 142! The mystery is not so great when you realize that the operation has gotten rid of the source of his fits, which had previously hampered his intelligence. When doctors saw him 15 years later, they described him as “having obtained a university doploma . . . [and now holding] a responsible administrative position with a local authority.” (18)
They also write about the story of an Argentinian boy who had a right hemispherectomy when he was 3-years-old who was notable for “the richness of his vocabulary and syntax” and also “attends English classes at school, in which he attains a high level of success (20; quote from Skoyles and Sagan, 2002: 238).
It is also a “medical myth that microcephaly (having a head smaller than two standard deviations (SD) below average circumference) is invariably linked to retardation.” (Skoyles and Sagan, 2002: 239).
There are some important things to be noted in regards to the study of Nariokotome boy’s skeleton and skull size. Skoyles and Sagan (2002: 240) write (emphasis mine):
So how well equipped was Homo erectus? To throw some figures at you (calculations shown in the notes), easily well enough. Of Nariokotome boy’s 673 cc of cortex, 164 cc would have been prefrontal cortex, roughly the same as half-brained people. Nariokotome boy did not need the mental competence required by cotemporary hunter-gatherers. … Compared to that of our distant ancestors, Upper Paleolithic technology is high tech. And the organizational skills used in hunts greatly improved 400,000 years ago to 20,000 years ago. These skills, in terms of our species, are recent, occurring by some estimates in less than the last 1 percent of our 2.5 million year existence as people. Before then, hunting skills would have required less brain power, as they were less mentally demanding. If you do not make detailed forward plans, then you do not need as much mental planning abilities as those who do. This suggests that the brains of Homo erectus did not arise for reasons of survival. For what they did, they could have gotten away with much smaller, Daniel Lyon-sized brains.
Lastly, I will touch on the fact that since we are running apes, that we need a narrow pelvis. As I stated above, our modern body plan came to be around 1.6 mya with the advent of erectus, which could be inferred from footprints (Steudel-Numbers, 2006; Bennett et al, 2009). Now the picture is beginning to become clearer: if people with brains the size of erectus could have intelligence in the modern range, and if our modern body plans evolved 1.6 mya (which is when our brains began to really increase in size due to metabolic constraints being unlocked due to erectus’ cooking ability), then you can see that it’d be perfectly possible for modern Homo sapiens to have brains the size of erectus while still having an IQ in the normal range.
Lastly, Skoyles and Sagan (2002: 245) write (emphasis mine):
Kanzi seems to do remarkably well with a chimp-sized brain. And while we tend to link retardation with small brains, we have seen that people can live completely normal lives while missing pieces of their brains. Brain size may enhance intelligence, but it seems we can get away without 3 pounders. Kanzi shows there is much potential in even 13 oz.
So Skoyles and Sagan do concede that brain size may enhance intelligence, however, as they have argued (and as Skoyles does in his 1999 paper), it is perfectly possible to live a normal life with half a brain, as well as have an average/above average IQ (as reviewed in Skoyles, 1999). So if people with erectus-sized brains can have IQs in the normal range and live normal lives, then brains must have increased for another reason, which Skoyles has argued is expertise capacity.
Large brains are, clearly, not needed for high IQs.
(Also search for this paper: Reiss, A. L., Abrams, M. T., Singer, H. S., Ross, J. L. & Denckla, M. B. (1996). Brain development, gender and IQ in children: A volumetric imaging study. Brain, 119, 1763-1774. where they show that there is a plateau, and a decrease in IQ in the largest brains; see table 2. I also reviewed some studies on TBI and IQ and how even those with severe TBI can have IQs in the normal range (Bigler, 1995; Wood and Rutterford, 2006; Crowe et al, 2012). Yet more evidence that people with half of their brains missing can lead normal lives and have IQs in the modern range.)
Dr. Julian Benoit (who also commented on the previous findings on Graecopithecus back in May) has now commented on this finding, writing in his article The theory that humans emerged in Africa is often questioned. That’s good for science:
The most recent piece of research that seeks to stake Europe’s claim as human ancestors’ birthplace centres on two teeth: a canine and a molar. This find was greeted with some excitement outside expert circles.
A few days ago it was announced that a few teeth were discovered in Germany which were about 9.7 million years old—about 4 million years older than the oldest hominin teeth discovered in Africa. Of course, you get click-baity mainstream news titles like Archaeology fossil teeth discovery in Germany could re-write human history. Who was the one who said that this finding ‘could rewrite human history’? The mayor of the town it was discovered in:
In the press conference announcing the find, Mainz Mayor Michael Ebling claimed the find would force scientists to reconsider the history of early mankind.
“I don’t want to over-dramatize it, but I would hypothesize that we shall have to start rewriting the history of mankind after today,” Ebling was quoted as saying.
That a mayor’s statement, who I presume has no scientific background, is being put into news titles that human history may need revision shows the low-quality of mainstream news articles when they report on new scientific findings.
There are a few problems with these claims that ‘human history needs to be rewritten’ due to a few teeth. Back in May, I covered how the finding that Graecopithicus Freybergi had a 4th molar ‘similar’ to us and was, therefore, a part of our species was incorrect and that we needed way more evidence than a few teeth and a jawbone. The same holds for these findings.
The researchers stated that they hesitated a year to publish the findings. I don’t see why; the only reason I can think of is because they believed that the finding was not ‘PC’ and therefore waited to publish their results (kind of like when Robert Putnam waited to publish his findings on diversity and social trust). However, this does not mean that the OoA hypothesis is debunked and that Europe is the home of Mankind.
However, other experts in the field say that this ‘hardly’ has us rethinking our view of human evolution. Only two teeth were discovered, and as National Geographic reported paleoanthropologist Ben Viola said by e-mail:
“I think this is much ado about nothing,” he says by email. “The second tooth (the molar), which they say clearly comes from the same individual, is absolutely not a hominin, [and] I would say also not a hominoid.”
Most of the experts contacted by National Geographic stated that the teeth looked like they belonged to pliopithecids, with Luntz’s team acknowledging that the tooth looked like it belonged to anapithecus, which is a primate that lived in Hungary and Austria around 10 million years ago. The molar is important, not because it shows that human ancestors evolved in Europe but because it would validate the fact that a femur found in the 1820s in Eppelsheim belonged to a pliopithecid and not a hominoid, says paleoanthropologist David Begun:
“The ‘canine’ looks to me like a piece of a ruminant tooth,” Begun says by email. Ruminants are cud-chewing, plant-eating mammals such as cows and sheep. “It has a funny break that makes it look a bit like a canine, but it is definitely not a canine, nor is it [from] a primate.”
David Begun also writes:
“The molar is important, because it validates an idea proposed by several researchers that a femur known from Eppelsheim since the 1820s actually does most likely belong to a pliopithecoid and not a hominoid,” says Begun.
Begun also says that the tooth looks like a ‘ruminant tooth’ (ruminant teeth being used to chew cud) and that “It has a funny break that makes it look a bit like a canine, but it is definitely not a canine, nor is it [from] a primate.”
So, as usual, such weak evidence being touted such as this has huge problems and the evidence that is being touted to rewrite human evolutionary history actually shows something completely opposite.
There are a few problems for the claim that human evolution needs to be rewritten based off of these findings:
- The paper is not peer-reviewed yet: Some may say that this shouldn’t matter, however, as I’ve shown from the few bits of peer commentary that I am able to find about this, a lot of people in the field have a few hangups about who the teeth belonged to and whether or not they belonged to members of our genus.
- You need more than two teeth to rewrite human evolutionary history: Since when are two teeth enough to say that human evolution needs a rewrite? Just like the findings back in May, this does not mean that we need to rethink human evolutionary history. You would need more than a few teeth to prove that Man began outside of Africa, just like you would need more than a few teeth to prove that man began IN Africa.
- The head researcher Herman Luntz was interviewed by Research Gate and he said:
RG: Can you say already what this find will mean for our understanding of human history?
Lutz: We want to hold back on speculation. What these finds definitely show us is that the holes in our knowledge and in the fossil record are much bigger than previously thought. So we’ve got the puzzle of having finds that, in terms of the expected timeline, don’t fit the region we found them in. We’ve got two teeth from a single individual. That means there must have been a whole population. It wouldn’t have been just one, all alone like Robinson Crusoe. So the question is, if we’re finding primate species all around the Mediterranean area, why not any like this? It’s a complete mystery where this individual came from, and why nobody’s ever found a tooth like this somewhere before.
So, of course, he wants to hold back on speculation, because he knows that you cannot make these great proclamations that human history needs to be rewritten due to two teeth—contrary to what the mayor of Mainz, Germany Michael Ebling claimed (a non-scientist). News outlets then take that statement and run with it, despite the caution from Luntz the head researcher of the study, the fact that it’s yet to pass peer review, and the fact that other researchers in the field have other things to say about it other than the fact that it may be a hominoid.
In the paper, Luntz et al (2017) write:
The relative size of the canine, i.e. the ratio of the buccal heights of C and M1, is similar to those of e.g. Dryopithecus sp., Ankarapithecus meteai but also Ardipethcus ramidus. Both, reduced size and shape of the canine likely largely indicate that the new species from Eppelsheim had lost a honing (C/p3) complex already ca. 9.7 Ma ago. From all information gathered up to now, the question arises, if the newly discovered Eppelsheim species may be related to members of the African hominin tribe.
Well the answer, according to others in the field, is that it belongs to a pliopithecid species, not a hominin. They, of course, claim that it bears a close resemblance to hominin teeth.
Of course, the two primates could have faced similar evolutionary pressure leading to convergence of traits. If the climate in one area is the same as in another area, then convergence of traits between two similar species is possible. This could also account for the similarities in teeth between this species (whatever it is) and hominins.
We’re going to need more than two teeth to rewrite human evolution. We’re going to need more than a jawbone to rewrite human evolution. The teeth that were discovered last year in Germany will need to go through a longer process to be shown to belong to a hominin species—because all of the evidence that we currently have about it points to it being a part of a priopithecus species—not a hominin species.
I recommend people wait and see/do some digging into claims from news articles that purport to show that human evolution needs ‘rewriting’, because, as you can see, this time the claim came from a governor of the town the teeth were found in. The teeth discovered look like they may be similar to species from early in our genus, however other experts in the field urge extreme caution in any interpretation of what they mean and who they belong to. Just like with the Graecopithcus case back in May, it seems to belong to another species of ape—though this one could be more closely related to us. No, this finding does not show that human evolution needs rewriting. I wish news agencies would set a higher standard of quality for their titles; but they are just trying to get clicks and will publish the most click-baity title possible. You’ll need more than a few teeth and jawbone to say that Man did not evolve in Africa, when all of the evidence we currently have points to Africa as the origin of Mankind.
Evidence for Natural Selection in Humans: East Asians Have Higher Frequency of CASC5 Brain Size Regulating Gene
Brain size is one physical difference that the races differ on. East Asians have bigger brains than Europeans who have bigger brains than Africans (Beals et al, 1984; Rushton, 1997). What caused these average differences and the ultimate causes for them have been subject to huge debate. Is it drift? Natural/sexual selection? Mutation? Gene flow? Epigenetic? One reason why brains would need to be large in colder climates is due to heat retention, while in tropical climates heads need to be smaller to dissipate heat. One of the biggest criticisms of HBD is that there is no/little evidence of recent natural selection between human races. Well, that has changed.
CASC5 “performs two crucial functions during mitosis, being required for correct attachment of chromosome centromeres to the microtubule apparatus, and also essential for spindle-assembly checkpoint (SAC) signaling” (Shi et al, 2016). The gene has been found to be important in recent human evolution along with neurogenesis.
Shi et al (2016) genotyped 278 Han Chinese (174 females and 104 males with a mean age of 36) who were free of maladies or genetic defects. They had the coding sequences of CASC5 for humans, chimpanzees, gorillas, baboons, gibbons, orangutans, tarsiers, Denisovans, and Neanderthals. They downloaded genotypes from the Human Genome Project for their analysis.
They compared CASC5 among three human species: humans, Neanderthals, and Denisovans. Using chimpanzees as an outgroup, they discovered 45 human-specific mutations, 48 Neanderthal-specific mutations, and 41 Neanderthal-specific mutations. Further, when one exon region was aligned among modern humans, non-human primates and other mammalian species, 12 amino acid sites showed divergence between modern humans, Neanderthals, and Denisovans with 8 occurring in modern humans. Of the 8 sites in humans, 6 are preserved which implies that they were important in our evolutionary history.
Shi et al (2016) write:
At the population level, among the 8 modern human amino acid changes, two (H159R and G1086S) are fixed in current human populations, and the other six are polymorphic Fig. 1). Surprisingly, 5 of the 6 amino acid polymorphic sites showed deep between-population divergence in allele frequencies. East Asians possess much higher frequencies of the derived alleles at four sites (T43R-rs7177192, A113T-rs12911738, S486A-rs2412541 and G936R-rs8040502) as compared to either Europeans or Africans (Fig. 1), while E1285K-rs17747633 is relatively enriched in Europeans (46%), and rare in East Asians (10%) and Africans (3%). No between-population divergence was observed for T598 M-rs11858113 (Fig. 1).
So East Asians have a much higher frequency of this derived trait. This is direct evidence for natural selection in recent human evolution in regards to the physical structure of the brain.
Since most of the amino acid polymorphic sites showed between-population divergence, they decided to analyze the three classical races using 1000 genomes. The variation between the races could be due to either genetic drift or natural selection. When they analyzed certain gene regions, they observed a signal of positive selection for East Asians but not Europeans or Africans. They further tested this selection signal using “the standardized integrated haplotype score (iHS) which is used for detecting recent positive selection with incomplete sweep (i.e. the selected allele is not yet fixed)” (Shi et al, 2016). Using this method, they discovered a few SNPs with large iHS values in Europeans (7 SNPs at 4.2 percent) and none in Africans.
They also conducted a genome-wide scan of Fst, iHS, and “XPCLR (searching for highly differentiated genomimc regions as targets of selective sweeps)” (Shi et al, 2016). Several SNPs had high Fst, iHS and XPCLR scores, which indicate that these alleles have been under positive selection in East Asians. Among the fixed amino acid sites in human populations, East Asians showed 5, Europeans showed 1, and Africans showed 0 which, the authors write, “[imply] that these amino acid changes may have functional effects” (Shi et al, 2016). Furthermore, using the HDGP, they obtained the frequency of the 6 amino acid sites in 53 populations. This analysis showed that 4 of the 6 amino acid sites are “regionally enriched in East Asia .. in line with the suggested signal of population-specific selection in this area” (Shi et al, 2016).
Then, since CASC5 is a brain size regulating gene, they looked for phenotypic effects. They recruited 167 Han Chinese (89 men, 178 women) who were free of maladies. They genotyped 11 SNPs and all of the frequencies followed Harvey-Weinberg Equilibrium (which states that allele and genotype frequencies will remain constant in a population from generation to generation in the absence of evolutionary pressures; Andrews, 2010). In the female sample, 5 regions were related to gray matter volume and four were on the amino acid polymorphic sites. Interestingly, the four alleles which showed such a stark difference between East Asians and Europeans and Africans showed more significant associations in Han Chinese females than males. Those carrying the derived alleles had larger brain volumes in comparison with those who had the ancestral alleles, implying recent natural selection in East Asia for brain size.
Shi et al (2015) also attempted two replications on this allele writing:
We further conducted a replication analysis of the five significant CAC5 SNPs in two other independent Han Chinese samples (Li et al. 2015; Xu et al. 2015). The results showed that three SNPs (rs 7177192, rs11858113 and rs8040502) remained significant in Replication-1 for total brain volume and gray matter volume (Xu et al. 2015), but no association was detected in Replication-2 (Li et al. 2015) (Table S4).
It is very plausible that the genes that have regulated brain growth in our species further aid differences in brain morphology within and between races. This effect is seen mostly in Han Chinese girls. Shi et al (2016) write in the Discussion:
If this finding is accurate and can be further verified, it suggests that that [sic] after modern humans migrated out of Africa less than 100,000 years ago, the brain size may still be subject to selection.
I do believe it is accurate. Of course, the brain size could still be subject to selection; there is no magic field shielding the brain against selection pressure. Evolution does not stop at the neck.
So Shi et al (2016) showed that there were brain genes under recent selection in East Asians. What could the cause be? There are a few:
- Climate: In colder climates you need a smaller body size and big brain to survive the cold to better thermoregulate. A smaller body means there is less surface area to cover, while a larger head retains heat. It, obviously, would have been advantageous for these populations to have large brains and thus get selected for them—whether by natural or sexual selection. This could also have to do with the fact that one needs bigger eyes in colder environments, which would cause an increase in the size of the brain for the larger eyes, as well as being sharper visio-spatially.
- Intelligence: East Asians in this study showed that they had high levels of gray matter in the skull. Further, large brains are favored by an intermediately challenging environment (Gonzalez-Forero, Faulwasser, and Lehmann, 2017).
- Expertise: I used Skoyle’s (1999) theory on expertise and human evolution and applied it to racial differences in brain size and relating it to the number of tools they had to use which differed based on climate. Now, of course, if one group uses more tools then, by effect, they would need more expertise with which to learn how to make those tools so large brains would be selected for expertise—especially in novel areas.
- Vision: Large brains mean large eyes, and people from cold climates have large eyes and large brains (Pearce and Dunbar, 2011). Decreasing light levels select for larger eye size and visual cortex size in order to “increase sensitivity and maintain acuity“. Large eyeballs mean enlarged visual cortices. Therefore, in low light, large brains and eyes get selected for so one can see better in a low light environment.
Of course, all four of the examples below could (and probably do) work in tandem. However, before jumping to conclusions I want to see more data on this and how the whole of the system interacts with these alleles and these amino acid polymorphic sites.
In sum, there is now evidence for natural selection on East Asians (and not Africans or Europeans) that favored large brains, particularly gray matter, in East Asians with considerable sexual dimorphism favoring women. Four of the genes tested (MCPH1, ASPM, CDK5RAP2, and WDR62) are regulated by estradiol and contribute to sexual dimorphism in human and non-human primates (Shi et al, 2016). Though it still needs to be tested if this holds true for CASC5.
This is some of the first evidence that I have come across for natural selection on genes that are implicated in brain evolution/structural development between and within populations. It does show the old “Rushton’s Rule of Three“, that is, Mongoloids on top, Caucasians in the middle, and Negroids on bottom, though Caucasians were significantly closer to Africans than Mongoloids in the frequency of these derived alleles. I can see a HBDer going “They must be related to IQ”, I doubt it. They don’t ‘have’ to be related to IQ. It just infers a survival advantage in low light, cold environments and therefore it gets selected for until it reaches a high frequency in that population due to its adaptive value—whether spreading by natural or sexual selection.
The notion that there is any ‘progress’ to evolution is something that I have rebutted countless times on this blog. My most recent entry being Marching Up the ‘Evolutionary Tree’? which was a response to Pumpkin Person’s article Marching up the evolutionary tree. Of course, people never ever change their views in a discussion (I have seen it, albeit it is rare) due, mainly to, in my opinion, ideology. People have so much time invested in their little pet theories that they cannot possibly fathom at the thought of being wrong or being led astray by shoddy hypotheses/theories that confirm their pre-existing beliefs. I will quote a few comments from Pumpkin Person’s blog where he just spews his ‘correlations with brain size and ‘splits’ on the ‘evolutionary tree” that ‘proves that evolution is progressive’, then I will touch on two papers (I will cover both in great depth in the future) that directly rebut his idiotic notion that so-called brain size increases across our evolutionary history (and even before we became humans) are due to ‘progress in evolution’
I think you mistyped that, but i see your point. Problem, however, most of your used phylogenies were unbalanced.
Based on the definition you provided, but not based on any meaningful definition. To me, an unbalanced tree is . . .
This is literally meaningless. Keep showing that you’ve never taken a biology class in your life, it really shows.
All it is is ignorance to basic biological thinking, along with an ideology to prove his ridiculous Rushtonian notion that ‘brain size increases prove that evolution is progressive’.
You have yet to present ANY scientific logic, and my argument about taxonomic specificity is clearly beyond you.
Scientific logic?! Scientific logic?! Please. Berkely has a whole page on misconceptions on evolution that directly rebut his idiotic, uneducated views on evolution. It doesn’t help that his evolution education most likely comes from psychologists. Nevertheless, PP’s ‘argument’ is straight garbage. Taxonomic specificity’ is meaningless when you don’t have an understanding of basic biological concepts and evolution. (I will have much more to say on his ‘taxonomic specificity’ below.)
Was every tree perfect? No, but most were pretty close, and keep in mind that any flawed trees would have the effect of REDUCING the correlation between brain size/encephalization and branching, because random error is a source of statistical noise which obscures any underlying relationship. So the fact that I repeatedly found such robust correlation in spite of alleged problems with my trees, makes my conclusions stronger, not weaker.
The fact that you ‘repeatedly’ found ‘correlations’ in spite of the ‘problems’ with your trees makes your ‘conclusions’ weaker. Comparing organisms over evolutionary time and you notice a ‘trend’ in brain size. Must mean that evolution is progressive and brain size is its calling card!!
I’m right and all the skeptics you cite are wrong.
Said like a true idealogue.
It’s not how many splits they have that I’ve been measuring, it’s how many splits occur on the tree before they branch off. Here’s a source from 2017:
Eukaryotes represent a domain of life, but within this domain there are multiple kingdoms. The most common classification creates four kingdoms in this domain: Protista, Fungi, Plantae, and Animalia.
So you needed ‘a source from 2017’ to tell you something that is literally taught on the first day of biology 101? Keep showing how uneducated you are here.
Nothing fallacious about a correlation between number of splits and brain size/encephalization.
Post hoc, ergo propter hoc is a Latin phrase for “after this, therefore, because of this.” The term refers to a logical fallacy that because two events occurred in succession, the former event caused the latter event.
Magical thinking is a form of post hoc, ergo propter hoc fallacy, in which superstitions are formed based on seeing patterns in a series of coincidences. For example, “these are my lucky trousers. Sometimes good things happen to me when I wear them.”
P1: X happened before Y.
P2: (unstated) Y was caused by something (that happened before Y).
C1: Therefore, X caused Y.
Here is PP’s (fallacious) logic:
P1: splits (X) happened before Y (brain size increase)
P2: (unstated) brain size increase was caused by something (that happened before brain size increaes [splits on the tree])
C1: therefore, splits caused brain size increase
Now, I know that PP will argue that ‘splits on the evolutionary tree’ denote speciation which, in turn, denotes environmental change. This is meaningless. You’re still stating that Y was caused by something (that happened before Y) and therefore inferring that X caused Y. That is the fallacy (which a lot of HBD theories rest on).
You don’t get it. Even statistically insignificant correlations become significant when you get them FIVE TIMES IN A ROW. If you want to believe it was all a coincidence, then fine.
Phylogenies are created from shared derived factors. Berkely is the go-to authority here on this matter. (No that’s not appeal to authority.) Biologists collect information about a given animal and then infer the evolutionary relationship. Furthermore, PP’s logic is, again, fallacious. Berkely also has tips for tree reading, which they write:
Trees depict evolutionary relationships, not evolutionary progress. It’s easy to think that taxa that appear near one side of a phylogenetic tree are more advanced than other organisms on the tree, but this is simply not the case. First, the idea of evolutionary “advancement” is not a particularly scientific idea. There is no unbiased, universal scale for “advancement.” Second, taxa with extreme versions of traits (which might be perceived as more “advanced”) may occur on any terminal branch. The position of a terminal taxon is not an indication of how adaptive, specialized, or extreme its traits are.
He may emphatically argue (as I know he will) that he’s not doing this. But, as can be seen from his article, X is ‘less advanced’ than Y, therefore splits, brain size, correlation=progress. This is dumb.
For anyone who wants to know how (and how not to) read phylogenies, read Gregory (2008). These idotic notions that PP espouses are what Freshman in college believe due to ‘intuitiveness’ about evolution. It’s so rampant that biologists have writen numerous papers on the matter. But some guy with a blog and no science background (and an ideology to hammer) must know more than people who do this for a living (educate people on phylogenies).
On Phil’s response to see the Deacon paper that I will discuss below, PP writes:
That’s not a rebuttal.
Yes it is, as I will show shortly.
The first paper I will discuss is Deacon’s (1990) paper Fallacies of Progression in Theories of Brain-Size Evolution. This is a meaty paper with a ton of great ideas about phylogenies, along with numerous fallacies that people go to when reading trees (my favorite being the Numerology fallacy, which PP uses, see below).
Deacon argues that since people fail to analyze allometry, this anatomists have mistaken artifacts for evolutionary trends. He also argues that many structural’brain size increases’ from ‘primitive to advanced forms’ (take note here, because this is what PP did and this is what discredits his idiotic ideology) are the result of allometric processes.
Source: Evolution of consciousness: Phylogeny, ontogeny, and emergence from general anesthesia Mashour and Alkire (2013)
This paper (and picture) show it all. This notion of scala naturae (which Rushton (2004) attempted to revive with r/K selection theory has been rebutted by me) was first proposed by Aristotle. We now know how the brain structure evolved, so the old ‘simple scala naturae‘ is, obviously, out of date in the study of brain evolution.
This paper is pretty long and I don’t have time to discuss all of it so I will just provide one quote that disproves PP’s ‘study’:
Whenever a method is discovered for simplifying the representation of a complex or apparently nonsystematic numerical relationship, the method of simplification itself provides new insight into the phenomenon under study. But reduction of a complex relationship to a simple statistic makes it far easier to find spurious relationships with other simple statistics. Numerology fallacies are apparent correlations that turn out to be artifacts of numerical oversimplification. Numerology fallacies in science, like their mystical counterparts, are likely to be committed when meaning is ascribed to some statistic merely by virtue of its numeric similarity to some other statistic, without supportive evidence from the empirical system that is being described.
Deacon also writes in another 1990 article titled Commentary on Ilya I. Glezer, Myron So Jacobs, and Peter J Morgane (1988) Implications of the “initial brain’9 concept for brain evolution in Cetacea:
The study of brain evolution is one of the last refuges for theories of progressive evolution in biology, but in this field its influence is still pervasive. To a great extent the apparent “progress” of mammalian brain evolution vanishes when the effects of brain size and functional specialization are taken into account.
(It’s worth noting that in the author’s response to Deacon, he did not have any qualms about ‘progressive brain-size’.)
In regards to PP’s final ‘correlation’ on human races and brain-size, this is a perfect quote from McShea (1994: 1761):
If such a trend [increase in brain size leading to ‘intelligence’] in primates exists and it is driven, that is, if the trend is a direct result of concerted forces acting on most lineages across the intelligence spectrum, then the inference is justified. But if it is passive, that is, forces act only on lineages at the low-intelligence end, then most lineages will have no increasing tendency. In that case, most primate species—especially those out on the right tail of the distribution like ours—would be just as likely to lose intelligence as to gain it in subsequent evolution (if they change at all).
The ‘trend’ is passive. Homo floresiensis is the best example. We are just as likely to lose our ‘intellect’ and our ‘big brains’ as we are to ‘get more intelligent’ and ‘smaller brains’. The fact of the matter is this: environment dictates brain size/whatever other traits an organism has. Imagine a future environment that is a barren wasteland. Kilocalories are scarce; do you think that humans would keep their big brains—which are two percent of their body weight accounting for a whopping 25 percent of total daily energy needs—without enough high-quality energy? When brain size supposedly began to increase in our taxa is when erectus learned to control fire and cook meat (Hlublik et al, 2017).
All in all, there is no ‘progress’ to evolution and, as Deacon argues, so-called brain-size increases across evolutionary time disappear after adjustments for body size and functional specialties are taken into account. However, for the idealogue who looks for everything they can to push their ideology/worldview, things like this are never enough. “No, that wasn’t a rebuttal! YOU’RE WRONG!!” Those are not scientific arguments. If one believes in ‘evolutionary progress’ and that brain-size increases are the proof in the pudding that evolution is ‘progressive’ (re has a ‘direction’), then they must rebut Deacon’s arguments on allometry and his fallacies in his 1990 paper. Stop equating evolution with ‘progress’. Though, I can’t fault laymen for believing that. I can, however, fault someone who supposedly enjoys the study of evolution. You’re wrong. The people you cite (who are out of their field of expertise) are wrong.
Evolution is an amazing process. To equate it with ‘progress’ does not allow one to appreciate the beauty of the process. Evolution does carry baggage with it, and if I weren’t so used to the term I would use Descent by Modification (DbM, which is what Darwin used). Nevertheless, progressionists will hide out in whatever safehold they can to attempt to push their idealogy that is not based on science.
(Also read Rethinking Mammalian Brain Evolution by Terrence Deacon. I go more in depth on these three articles in the future.)
The other day Anonymous Conservative (AC) published an article titled Criticism Of r/K Theory In The Comments. I’m not too worried about what he wrote in the main article (I may tackle that later if I feel up to it), but what I am worried about is someone’s critique of my article r/K Selection Theory: A Response to Anonymous Conservative. Since this guy uses AC’s writings who, of course, is influenced by Rushton’s application of r/K to humans, it shows that he’s pretty clueless about 1) the theory as a whole and 2) the theory’s ultimate status in biology. (Also check out Phil’s comments in the AC thread.)
The individual in question, one ‘Samuel Skinner’ calls my critique of AC “genuinely bad” and that he would “cover the most obvious mistakes“, well let’s take a look at my ‘genuinely bad‘ critique to AC.
RR: You don’t get it. Mongoloids being r-selected is straight from Rushton. He asserts that they have cold-adaptations. Cold adaptations are due to cold weather. Cold weather is an agent of r-selection (temperature extreme).
Samuel Skinner: Mongoloids have a variety of genetic adaptions to cold. If you drop one buck naked in the winter, they will still freeze to death. The actual adaption they have is wearing thick clothing covering the entire body, something that is both K and not existent in Africa. Needless to say knowing how to gather materials, make clothing and maintain it is a K selective pressure.
So “the actual adaptation they have” is to “wear thick clothing“? This is bullshit and you know it. I covered human physiological adaptations to the cold last month: Human Physiological Adaptations to Climate. Clothes weren’t made in Africa? “Knowing how to gather materials, make clothing and maintaining it” is not a “K selective pressure“.
RR: Endemic (native) disease is an agent of K-selection. Since the disease is constant, then the population under that agent of K-selection can prepare ahead for disease.
Samuel Skinner: That requires the preparation to actually work; if preparation has less effect on genetic pay offs then having children faster, having children faster wins.
The preparation does work. In the case of malaria (an endemic disease), one-fifth of patients use traditional malarial remedies in malaria-stricken countries (Wilcox and Bodecker, 2004).
Endemic and infectious disease is an agent of K-selection:
(From Anderson, 1991: 53)
RR: Do groups not work together in Africa to reach common goals? In the Pleistocene as well? Citations? Think before you write (and cite), because hunting bands in our species began with Homo erectus.
Samuel Skinner: NPC talks about clannishness and IQ difference in other posts. So he does believe that groups in Africa do not work together to reach common goals. I’m honestly not sure what he is thinking here.
Yes I do. But to say that ‘Africans don’t work together’ is stupid because Africa is a huge continent. Which African ethnies? Etc. And that’s also an incorrect claim.
RR: Density-dependent pressures are things such as endemic disease in Africa—which is necessary for a K-selected history since density-dependent natural selection occurs at or close to the environmental carrying capacity
Samuel Skinner: Yes, if a disease is transmitted through person to person contact and non-discriminatory. Malaria is transmitted through mosquitoes; the amount adding additional people increases its rate is negligible.
“This therefore provides empirical confirmation that sex ratio has an immediate impact on transmission success and that it is density-dependent” (Mitri et al, 2009). Endemic disease (like malaria) work in a density-dependent fashion (Anderson, 1991: 51).
Here is what people like Samuel Skinner and AC don’t get: r/K selection theory WAS discarded; it is no longer in use. Age-specific mortality better explains these trends than r/K selection (Reznick et al, 2002: 1518). I’ve also covered how the so-called ‘unidimensional construct’ or r on one end and K at another is wrong: “It appears that the original HKSS items are best represented as four distinct but related dimensions, and do not represent a unidimensional construct. This conclusion is reinforced by relationships between HKSS total scores and life history measures: The significant correlations that were found were contrary to the predictions made by the Differential K literature (Figueredo et al., 2013; Rushton, 1985). We found that high K scores were related to earlier sexual debut and unrelated to either pubertal onset or number of sexual partners. This suggests that the HKSS does not reflect an underlying “K dimension” (Copping, Campbell and Muncer, 2014).
It truly is tiring rebutting the same old bullshit arguments on r/K theory. I see AC’s bullshit on Twitter when I search ‘r/K Selection Theory’, but the individual who pushes the bullshit will not accept my invitation to come to this blog and discuss it with me.
The most important thing to know here is that the unidimensional construct that Pianka (1970) formulated is wrong. Joseph Graves (2002) reviews some of the literature on the theory, showing that Pianka’s (1970) verbal theory is wrong, and that r/K selection fell out of favor in the late 70s. It’s worth noting that Pianka gave NO experimental rationale (Graves, 2002: 135) to his unidimensional construct (which Copping, Campbell and Muncer, 2014). Do you see how this theory holds no weight in evolutionary biology anymore?
Here is what Reznick et al (2002) write:
Although life-history theory has shifted away from a focus on r- and K-selection, the themes of density-dependent regulation, resource availability, and environmental fluctuations are integral to current demographic theory and are potentially important in any natural system
I see the term density-dependent regulation, which I do not see on AC’s blog (the only thing that comes up if you search that term on his blog are the responses to me… that should tell you something). In regards to resource availability Reznick et al (2002: 1517) write: We have also found a potential role of resource availability, either as a consequence of environmental factors that are correlated with, but otherwise independent of predators, or as a consequence of indirect effects of predation (Reznick et al. 2001)”. If I were you I’d read some of the literature on this before writing more bullshit.
Skinner also writes: “Again, not following. The link between fertility and disease is pretty clear- after a die off the population rebounds. If a population is near carrying capacity and suffers a die off, the growth rate of the survivors increases.” Except African populations have had much more time to reach their environmental carrying capacity and to experience the K-selected agents of natural selection, like endemic disease (Anderson, 1991: 59).
Then AC jumps in and writes: “You cannot take a Biology 101 class without learning about r/K. It is in the textbooks, and it is seen as an excellent theory, akin to Newtonian Physics. Sure relativity and Quantum Mechanics came along and showed that Newtonian physics wasn’t the entire ball of wax. But you still learn Newtonian Physics, because it is fundamental to understanding everything else.” This, again, is bullshit. AC, have you taken a Bio 101 class? I took one. Not one mention of this discredited theory, I have an in use biology textbook (Understanding Biology, 2nd edition, Mason et al, 2017; check pages 905-908 in the textbook to verify this) and in the section on reproductive strategies (which is what r/K selection theory is, at its core) r/K selection is not mentioned once. Why make claims that you know you cannot verify?
AC: “What we are doing here is not something where you can point to a single old study, and say, here it all is, in one place. Bringing all this together is new, even if what is being brought together is well established.“
That doesn’t mean it’s right.
AC: The issue is, you have one area of study of humans (political science) where it is long established that humans spontaneously diverge into two groups, which the literature has recognized are so divergent that they call them Left and Right, as in each points in the opposite direction.
So stop dodging me and answer this question: Are liberals and conservatives local populations? If so, where did they evolve?
AC: “Now I know you didn’t read the book because you are hung up on the use of the phrase “r/K Theory.” In the book there is a chapter devoted to that. I use the meme of r/K Theory for the same reason it is taught in biology – it is a quick way to bring people up to speed on the purposes of these traits, and how they affect reproduction/survival under different conditions.”
Don’t worry; I’ll read your book soon enough and will probably have tons of material to rebut. Anyway, using discredited bio theories isn’t a good way to push something.
AC: “If it is done right, this will ultimately be a massive field of study with thousands of biologists and political scientists taking it apart and trying to figure how aggressive stimuli affect people’s r/K traits, vs sexual stimuli, vs pleasureable things like food, vs quick blips of K followed by long periods of r, vs long constant K, vs disease mortality that is totally random, and on and on.”
You have some strange dreams. It won’t happen. Individuals WITHIN A SPECIES are not R OR K. R AND K ARE NOT ADJECTIVES (Anderson, 1991: 57).
AC: “On Rushton, unless he ever mentioned politics (he didn’t),“
AC: “You have married black conservatives and married white conservatives and married Asian conservatives. They all have more in common psychologically than the leftists of their fellow races. Mixing them along racial lines only muddies the waters, and hides that all races have been exposed to harshness and ease, and have adapted the requisite psychologies to function and persist under either.“
No it doesn’t ‘muddy the waters’. I believe now you’ll point to black Trump supporters going against BLM or white Leftists going against their interests. SO WHAT. You can create any just-so story you’d like, you won’t be right.
Something AC doesn’t get is that using the discredited r/K continuum, conservatives would be r (lower IQ, more children; women who reported being religious stated that having children was more important to them; Hayford and Morgan, 2008) in comparison to liberals who would be K (fewer children, higher IQs). Of course, he just immediately states that cons are K and libs are r, since the verbal theory from Pianka (1970) had the ‘good traits’ on K and ‘bad traits’ on r. (Read r/K theory: Conservatives = r, liberals = K (reminder to the ignorant)). I’ve already covered that libs are more intelligent than cons (Kanazawa, 2010; Kanazawa, 2014), and that conservative countries have lower IQs (and are non-white and third world) in comparison to liberal countries (which are majority white…). Conservatives are more likely to be religious (Morrison, Duncan, and Parton, 2015; McAdams et al, 2015), and religious people have lower IQs (Zuckerman, Silberman, and Hall, 2013; Ritchie, Gow, and Deary, 2014; Pennycook et al, 2016; Dutton and Linden, 2017). Intelligence is also associated with social and economic liberal views (Carl, 2014). Lastly, research into the psychology of continents shows that liberal continents are more intelligent than conservative continents (African countries conservative, European countries liberal… what’s that tell you?) (Stankov and Lee, 2016). So, using Rushton’s/Pianka’s continuum, who looks r and K now?
This, as usual, is the perfect example of implicit bias. My team is best and has the good traits, the other team is worse and has the bad traits. It’s dumb, it doesn’t make sense. AC will try to get ‘the truth’ about this theory out to people, well he has a foil in myself. I enjoy talking about this and debating it, but it seems like most people don’t understand the ecology behind the theory. They have their biases and will search for anything to confirm them. That’s not science.
Stop pushing r/K theory. It’s long dead. Just because some non-specialist idealogue pushes something and warps studies to fit his views while ignoring contrary evidence, DOES NOT mean that the theory is ‘back’ in style or anything to that effect. One biased person picked up the dead body of the (discredited) r/K continuum and attempted to revive it. Well I’ve shot it back down. It’s dead. Let it rest in peace and stop attempting to revive it.
Also see my other articles on r/K Selection Theory
Also read: r/k selection political theory is rubbish
Humans are adapted to numerous ecosystems on earth. This is only possible due to how our physiological systems interact with the environment in a homeodynamic way. This allowed us to spread across the globe, far away from our ancestral home of Africa, and thusly certain adaptations evolved in those populations—which was driven by our intelligent physiology. I will touch on human cold and hot adaptations, how physiology adapts to the two climates and what this means for the populations that make up Mankind.
Physiological adaptations to Arctic climates
The human body is one of the most amazing and complex biological systems on earth. The human body lives and dies on its physiology and how it can adapt to novel environments. When Man first trekked out of Africa into novel environments, our physiology adapted so we could survive in novel conditions. Over time, our phenotypes adapted to our new climates and humans began looking different from one another due to the climatic differences in their environments.
There is a large body of work on human cold adaptation. Thermal balance in humans is maintained by “vasodilation/vasoconstriction of the skin and peripheral tissues within the so-called thermo-neutral zone” (Daanen and Lichtenbelt, 2016). Two other adaptations occur in the cold: shivering thermogenesis (ST) and non-shivering thermogenesis (NST) and one in the heat (the evaporation of sweat). Humans are not Arctic animals by nature, so, therefore, venturing into novel environments would incur new physiological adaptations to better deal with the cold.
Heat is induced by the body in cold climates by shivering (Tikuisis, Bell, and Jacobs, 1991; Daanen and Lichtenbelt, 2016). So, therefore, people in colder climates will have higher metabolisms than people in tropical environments, to generate more body heat for vital functioning. People living in Arctic environments have fewer sweat glands than people who live in the tropics. Sweating removes heat from the body, so having more sweat glands in colder climates would not be conducive for survival.
People who evolved in Arctic climates would also be shorter and have wider pelves than people who evolved in the tropics. This is seen in Neanderthals and is an example of Cold adaptations also show up in the Greenlandic Inuit due to extinct hominins like the Denisova (Fumagalli et al, 2015).
We can see natural selection at work in the Inuits, due to adaptation to Arctic climates (Galloway, Young, and Bjerregaard, 2012; Cardona et al, 2014; Ford, McDowell, and Pierce, 2015; NIH, 2015; Harper, 2015; Tishkoff, 2015). Climate change is troubling to some researchers, with many researchers suggesting that global warming will have negative effects on the health and food security of the Inuit (WHO, 2003; Furgal and Seguin, 2006; Wesche, 2010; Ford, 2009, 2012; Ford et al, 2014, 2016; McClymont and Myers, 2012; Petrasek, 2014; Petrasek et al, 2015; Rosol, Powell-Hellyer, and Chan, 2016). This Inuit are the perfect people to look to to see how humans adapt to novel climates—especially colder ones. They have higher BMIs which is better for heat retention, and larger brains with wider pelves and a shorter stature.
Metabolic adaptations also occur due to BMI, which would occur due to diet and body composition. Daanen and Lichtenbelt, (2016) write:
Bakker et al.,48 however, showed that Asians living in Europe had lower BAT prevalence and exhibited a poorer shivering and non-shivering response to cold than Caucasians of similar age and BMI. On the other hand, subjects living in polar regions have higher BMI, and likely more white fat for body energy reserves and insulation.49 This cannot be explained by less exercise,50 but by body composition51 and food intake.49
Basal metabolic rate (BMR) also varies by race. Resting metabolic rate is 5% higher in white women when compared to black women (Sharp et al, 2002). Though low cardiovascular fitness explains 25 percent of the variance in RMR differences between black and white women (Shook et al, 2014). People in Arctic regions have a 3-19 higher BMR than predicted on the basis of the polar climates they lived in (Daanen and Lichtenbelt, 2016). Further, whites had a higher BMR than Asians living in Europe. Nigerian men were seen to have a lower BMR than African-American men (Sharp et al, 2002). So, whites in circumpolar locales have a higher BMR than peoples who live closer to the equator. This has to do with physiologic and metabolic adaptations.
Blacks also show slower and lower cold induced vasodilation (CIVD) than whites. A quicker CIVD in polar climates would be a lifesaver.
However, just our physiologic mechanisms alone aren’t enough to weather the cold. Our ingenuity when it comes to making clothes, fire, and finding and hunting for food are arguably more important than our bodies physiologic ability to adapt to its present environment. Our behavioral plasticity (ability to change our behavior to better survive in the environment) was also another major factor in our adaptation to the cold. Then, cultural changes would lead to genetic changes, and those cultural changes—which were due to the cold climates—would then lead to more genetic change and be an indirect effect of the climate. The same, obviously, holds for everywhere in the world that Man finds himself in.
Physiologic changes to tropical climates
Physiologic changes in tropical climates are very important to us as humans. We needed to be endurance runners millions of years ago, and so our bodies became adapted for that way of life through numerous musculoskeletal and physiologic changes (Lieberman, 2015). One of the most important is sweating.
Sweating is how our body cools itself and maintains its body temperature. When the skin becomes too hot, your brain, through the hypothalamus, reacts by releasing sweat through tens of millions of eccrine glands. As I have covered in my article on the evolution of human skin variation, our loss of fur (Harris, 2009) in our evolutionary history made it possible for sweat to eventually cool our body. Improved sweating ability then led to higher melanin content and selection against fur. Another hypothesis is that when we became bipedal, our bodies were exposed to less solar radiation, selecting against the need for fur. Yet another hypothesis is that trekking/endurance running led to selection for furlessness, selecting for sweating and more eccrine glands (Lieberman, 2015).
Anatomic changes include long and thin bodies with longer limbs as heat dissipation is more efficient. People who live in tropical environments have longer limbs than people who live in polar environments. These tall and slender bodies are what is useful in that environment. People with long, slender bodies are disadvantaged in the cold. Further, longer, slender bodies are better for endurance running and sprinting. They also have narrower hips which helps with heat dissipation and running—which means they would have smaller heads than people in more northerly climes. Most adaptations and traits were once useful in whichever environment that organism evolved in tens of thousands of years ago. And certain adaptations from our evolutionary past are still evident today.
Since tropical people have lower BMRs than people at more northerly climes, this could also explain why, for instance, black American women, have higher rates of obesity than women of other races. They have a lower BMR and are sedentary and eat lower-quality food so food insecurity would have more of an effect on that certain phenotype. Africans wouldn’t have fast metabolisms since a faster metabolism would generate more heat.
Physiologic changes due to altitude
The last adaptation I will talk about is how our bodies can adapt to high altitudes and how it’s beneficial. Many human populations have adapted to the chronic hypoxia of high latitudes (Bigham and Les, 2014) which, of course, has a genetic basis. Adaptation to high altitudes also occurred due to the introgression of extinct hominin genes into modern humans.
Furthermore, people in the Andean mountains, people living in the highlands of Kenya and people living on the Tibetan plateau have shown that the three populations adapted to the same stress through different manners. Andeans, for instance, breathe the same way as people in lower latitudes but their red blood cells carry more oxygen per cell, which protects them from the effects of hypoxia. They also have higher amounts of hemoglobin in their blood in comparison to people who live at sea level, which also aids in counterbalancing hypoxia.
Tibetans, on the other hand, instead of having hematological adaptations, they have respiratory adaptations. Tibetans also have another adaptation which expands their blood vessels, allowing the whole body to deliver oxygen more efficiently to different parts. Further, Ethiopians don’t have higher hemoglobin counts than people who live at sea level, so “Right now we have no clue how they do it [live in high altitudes without hematologic differences in comparison to people who live at sea level]”.
Though Kenyans do have genetic adaptations to live in the highlands (Scheinfeldt et al, 2012). These genetic adaptations have arisen independently in Kenyan highlanders. The selective force, of course, is hypoxia—the same selective force that caused these physiologic changes in Andeans and Tibetans.
The human body is amazing. It can adapt both physiologically and physically to the environment and in turn heighten prospects for survival in most any environment on earth. These physiologic changes, of course, have followed us into the modern day and have health implications for the populations that possess these changes. Inuits, for instance, are cold-adapted while the climate is changing (which it constantly does). So, over time, when the ice caps do melt the Arctic peoples will be facing a crisis since they are adapted to a certain climate and diet.
People in colder climates need shorter bodies, higher body fat, lower limb ratio, larger brains etc to better survive in the cold. A whole slew of physiologic processes aids in peoples’ survival in the Arctic, but our ability to make clothes, houses, and fire, in conjunction with our physiological dynamicness, is why we have survived in colder climates. Tropical people need long, slender bodies to better dissipate heat, sweat and run. People who evolved in higher altitudes also have hematologic and respiratory adaptations to better deal with hypoxia and less oxygen due to living at higher elevations.
These adaptations have affected us physiologically, and genetically, which leads to changes to our phenotype and are, therefore, the cause of how and why we look different today. Human biological diversity is grand, and there are a wide variety of adaptations to differing climates. The study of these differences is what makes the study of Man and the genotypic/phenotypic diversity we have is one of the most interesting sciences we have today, in my opinion. We are learning what shaped each population through their evolutionary history and how and why certain physical and physiologic adaptations occurred.
When organisms that we don’t normally signify as ‘intelligent’ do, indeed, show ‘intelligent’ behavior, our definition of the word—what we call ‘intelligent’ behavior—needs to be reevaluated. Bacteria and other microbes can certainly respond to cues from their environments and communicate with each other. So if bacteria can respond to environmental stimulus by having plastic behavior, then they do show a semblance of ‘intelligence’. Just because bacteria don’t talk doesn’t mean that they are not ‘intelligent’ in their own right.
Bacteria respond to cues from their environment, just like any other intelligent organism. That means that they have behavioral plasticity, the ability to change their behavior based on what occurs in their environments. Bacteria have been shown to exhibit behaviors we would call ‘intelligent’, i.e., acquiring information, storage, processing, use of information, perception, learning, memory, and decision-making (Lyon, 2015). It is proposed that “bacteria use their intracellular flexibility, involving signal transduction networks and genomic plasticity, to collectively maintain linguistic communication: self and shared interpretations of chemical cues, exchange of chemical messages (semantic) and dialogues (pragmatic)” (Jacob et al, 2004).
Clearly, bacteria can and do adapt at the phenotypic level, not only the genotypic level as some have asserted in the past. Using this definition of intelligence, that is, being able to perceive, process and integrate information about the state of the environment to change the organism’s behavior is intelligent behavior (Pinto and Mascher, 2016), all organisms, from bacteria to humans and in between are intelligent. If bacteria do show evidence of behavioral plasticity—and they do—then we must look at them as intelligent creatures, as well as come to the realization that all biological organisms are, in their own right, intelligent. Intelligence is not only for any ‘higher’ organisms; so-called ‘lower’ organisms do show behavioral plasticity, meaning they know what is occurring in their environment. Is that not intelligent?
Any organism that can immediately act in a different way when its environment changes can, in my opinion, be said to be intelligent. All biological organisms have this ability to ‘go off of their genetic coding’, if you will, and change their behavior to match what is currently going on in their environment. Furthermore, the number and fraction of single transduction genes can be used as a measure of ‘bacterial IQ’ (Sirota-Mahdi et al, 2010).
This, of course, has implications for our intelligent physiology. Since our physiological systems incorporate the intelligent processes of the intelligent cell, then, on a larger scale, our physiology is also intelligent. Our physiology is constantly responding to cues from the environment, attempting to maintain homeostasis. Since our body has a need to stay in homeostasis, then our physiological systems are indeed intelligent in their own right. They incorporate the processes of the intelligent cell; looking at our physiology in this way, we can see how and why these systems are intelligent.
Further, physiologists have been referring to physiological systems as “homeodynamic”, rather than “homeostatic”, seeing chaotic states as healthy “allowing organisms to respond to circumstances that vary rapidly and unpredictably, again balancing variation and optimization of order with impressive harmony” (Richardson, 2012). If our physiological systems can do this, are they not intelligent? Further, according to physiologist Dennis Noble, “Genes … are purely passive. DNA on its own does absolutely nothing until activated by the rest of the system through transcription factors, markers of one kind or another, interactions with the proteins. So on its own, DNA is not a cause in an active sense. I think it is better described as a passive data base which is used by the organism to enable it to make the proteins that it requires.” So, as you can see, genes are nothing without the intelligent physiology guiding then. This is only possible with physiological systems, and this begins with the intelligent cell—intelligent microbes.
Some people misunderstand what genes are for and what they do in the body. The gene has long been misunderstood. People don’t understand that genes direct the production of proteins. Since physiological systems—at their core—are run by microbes, then the overall physiological system is itself intelligent. Genes, on their own, are not the masters but the servants. Genes do code for proteins that code for traits, but not under their own direction; they are directed by intelligent systems.
Think of how our gut microbiome co-evolved with us. Knowing what we now know about intelligent cells, we can also say that, by proxy, our microbiome is intelligent as well.
Understanding intelligent cells will lead us to understand intelligent physiology then, in turn, lead us to understand how genes are the servants—not the masters as is commonly asserted—of our traits. Physiology is an intelligent system, and since it is intelligent it can then react to cues from the environment, since it is made up of smaller cells, which make up the larger whole of the intelligent physiological system. These intelligent systems that we have evolved are due to the changeability of our environments in our ancestral past. Our physiology then evolved to be homeodynamic, attempting to maintain certain processes. The ever-changing environment that our genus evolved in is the cause for our homeodynamic intelligent physiology, which begins at the smallest levels of the cell.
The intelligent microbes are the smaller part of the larger whole of the intelligent physiological system. Due to this, we can say that at the smallest levels, we are driven by infinitesimally small microbes, which, in a way, guide our behavior. This can definitely be said for our gut microbiome which evolved with us throughout our evolutionary history. Our microbiome, for instance, had to be intelligent and communicate with each other to maintain our normal functioning. Without these intelligent cells, intelligent physiology would not be possible. Without ever-changing dynamic environments, our intelligent physiology and intelligent cells would have never evolved.
Intelligent physiology evolved due to the constant changeability of the new environments that our ancestors found themselves in. If we would have evolved in, say, more stable, unchanging environments, our physiological systems would have never evolved how they did. These intelligent physiological systems can buffer large ranges of physiological deficiencies. The evolvability of these systems due to the changeability of our ancestral environments is the cause of our amazing physiological intelligence, developmental plasticity, and microbial intelligence.
When you think about conception, when a baby is forming in the womb, it becomes easier to see how our physiological systems are intelligent, and how genes are the slaves—not masters—of our development. Intelligence is already in those little cells, it just needs an intelligent physiology for things to be set into motion. This all goes back to the intelligent cells which make up the larger part of intelligent physiology.
There are numerous misconceptions about evolution. One of the largest, in my opinion, is that there is some sort of intrinsic ‘progress’ to evolution. This is inferred from the fact that the first life—bacteria—are simpler and less ‘complex’ than so-called ‘higher’ organisms. This notion is still pushed by some, despite the fact that it is a discredited concept.
The concept of scala naturae was first proposed by Aristotle (Hodos, 2009; Werth, 2012; Diogo, Ziermann, and Linde-Medina, 2014). This notion was held until Darwin’s landmark book On the Origin of Species (Darwin, 1859) when Darwin proposed the theory of evolution by natural selection. However, the notion of the scala naturae is still entrenched in modern-day thought, from the layman all the way to educated scientists. This notion is wrong.
Neuroscientist Herculano-Houzel writes on page 94 of her book The Human Advantage A New Understanding of How Our Brain Became Remarkable:
Moreover, evolution is not synonmous with progress, but simply change over time. And humans aren’t even the youngest, most recently evolved species. For example, more than 500 new species of cichlid fish in Lake Victoria, the youngest of the great African Lakes, have appeared since it filled with water some 14,500 years ago.
When people think of ‘progression up this evolutionary tree’ they look at Man as the ultimate culmination of the evolutionary process—as if every event that occurred before the Dawn of Man was setting the stage for us to be here. This, of course, goes back to the scala naturae concept. The ‘lower’ animals are the ones that are less ‘complex’ than the ‘higher’ animals. The notion that there was a ‘march of progress’ towards Man is erroneous (see Gould, 1989: 27-45 for a review).
Indeed, even Darwin himself didn’t believe in some ‘straight line’ to the evolutionary process. In one of his notebooks, he drew a ‘coral of life’ (seen below):
Notice how there are no ‘lower’ or ‘higher’ organisms and each branch branches off to the side, with no way of denoting which organism has ‘progressed’ more?
The scala naturae proposes that inanimate objects, to plants, to animals can all be placed somewhere on this ladder of ‘progress’, which eventually culminate with Man at the top—as if we are the ultimate culmination of evolutionary history and time—like we were preordained to be here. The scala naturae is still with us today. Why should we view humans as ‘higher than’ other organisms? It doesn’t make sense. It’s clearly steeped in a large anthropometric bias.
Indeed, the scala naturae is so entrenched in our minds that modern-day biologists still use terms that would denote ‘higher’ and ‘lower’, the scala naturae. Rigato and Minelli (2013) data mined 67,413 biological articles published between the years 2005 and 2010 looking for signs of pre-evolutionary language (e.g., lower vs. higher vertebrates and lower vs. higher plants). Of the 67,413 article that were mined for data, 1,287 (1.91%) returned positive hits for scala naturae language. Shockingly, the journal Molecular Biology and Evolution had frequent scala naturae language (6.14 %) along with the journal Bioessays (5.6%) and the Annual Review of Ecology, Evolution, and Systematics (4.82%). Clearly, misconceptions about the nature of evolution can still persist in the modern-day amongst experts (that doesn’t mean that the notion of the scala naturae is correct since specialists still use some of the terminology, however). In terms of scala naturae thinking by country, Russia topped the list followed by Japan, Germany, Israel, and France.
This notion of ‘progress’ to evolution—that there is some sort of scala naturae with has ‘primitive’ organisms on the bottom with ‘advanced’ organisms at the top is wrong. When comparing organisms, the comparison isn’t between which organism is more ‘primitive’ or ‘advanced’. The comparison is between ancestral and derived, so the only meaningful comparison is to say that organism A is more like the common ancestor (ancestral) while organism B has derived traits in comparison to the common ancestor (Gregory, 2008).
It is further assumed that earlier organisms are more ‘primitive’ than organisms that are younger. This is false. Once organisms diverge from a common ancestor, they both share a mixture of ancestral and derived traits; ancestral and derived organisms share a mix of ancestral and derived traits from said common ancestor (Crisp and Cook, 2005: 122). Furthermore, ‘early’ does not denote ‘primitiveness’ (Gould, 1997: 36). So to say that, for instance, ‘this organism on this tree did less/no branching than others and is therefore primitive’ is incorrect. It is fallacious to make a comparison between ‘primitive’ and ‘advanced’ organisms. For instance, one may look at a phylogeny and see a straight line and assume that no change has occurred. This is wrong.
The terminology ‘driven’ and ‘passive’ is used to denote trends in complexity. Is the trend driven or passive? Large amounts of research has been done into this matter (Gould, 1996; McShea, 1996) with no clear-cut answer. What is increasing? Complexity? The thing about ‘complexity’ (whatever that is) is that it may be a trend, but it is not an inevitability (Werth, 2012: 2135). Since life began at the left wall—where no organism can get any simpler—there was only one way to go: up. Any organism that arises in between the left and right walls can either become more or less complex depending on what is needed in that particular ecosystem.
Gould (1996) speaks of a drunkard leaving a bar. The drunkard leans on the bar wall (the left wall of complexity) and continuously stumbles toward the gutter (the right wall of complexity). The drunkard may go back and forth, touching the bar wall all the while getting closer to the gutter which each stumble. The drunkard will—eventually—end up in the gutter. Now we can look at the right wall of complexity as us humans and the left wall as bacteria. Any organism caught in the middle of the walls can either get less or more complex, but no simpler than the left wall—where life began. Some may say that this denotes ‘progress’, however, since life began constrained at the left wall, there was no way to go but ‘up’.
McShea (1994: 1761) notes:
If such a trend in primates exists and it is driven, that is, if the trend is a direct result of concerted forces acting on most lineages across the intelligence spectrum, then the inference is justified. But if it is passive, that is, forces act only on lineages at the low-intelligence end, then most lineages will have no increasing tendency. In that case, most primate species—especially those out on the right tail of the distribution like ours—would be just as likely to lose intelligence as to gain it in subsequent evolution (if they change at all).
Are there any instances like this in our genus? Of course there are, with the most famous (and most studied) being Homo floresiensis. I’ve written twice before about how the evolution of floresiensis proves that 1) evolution is not progress and 2) large brains need high-quality energy and without that brain size—and body size—will shrink. Indeed, a new paper on the evolution of floresiensis lends credence to the idea that floresiensis is a derived form of erectus (Diniz-Filho and Raia, 2017). Their analysis lends credence to the support that floresiensis is derived from erectus and not habilis. No matter which hominin floresiensis evolved from, this shows how critical the quality of energy is for maintaining a large brain and body size and, without large amounts of high-quality energy then reductions in brain and body size will persist. This, yet again, lends more credence to my argument of non-progressive evolution.
Now, I must talk about the scala naturae and its involvement in attempting to figure out the evolution of the human brain. Does the supposed increase in brain size denote ‘progress’ in evolution? No, it does not.
Brains are made from metabolically expensive tissue; that is, the larger a brain is the more kcal are needed to power it. Brains and the tissue that compose it (along with other bodily structures) are so expensive that there is a trade-off between elaborate defense mechanisms and brain size—as EQ decreases, defense mechanisms get more elaborate and vice-versa (Stankowich and Romero, 2017). So organisms don’t need intelligence—and [sometimes] the larger brain that comes with it—if they have evolved elaborate defense mechanisms to where they don’t need a large brain to survive.
The increase in brain size over the past few million years in our genus Homo is pointed at as proof that evolution is ‘progressive’, however that is literally only one metric and any wild swings in environment can and will select for smaller brains. The point is that increases in brain size are due to local change, so therefore trends in the opposite direction can and do occur.
The terms ‘higher and lower’ in regards to the scala naturae have been discredited (Diogo, Ziermann, and Linde-Medina, 2014: 18). Indeed, when we believe that things may go our way when, say, we are testing ourselves compared to other animals we will invoke the scala naturae. But what if we humans are not the ‘best’ at any given task tested? Eleven animal species (including human infants) were tested to analyze color processing speed. First came honeybees, then fish, then birds and lastly human infants. Of course this contradicted the scala naturae concept, and some people even argued that learning speed is not a useful measure of intelligence (Chittka et al, 2012)! This scala naturae thinking would have us believe that we should be on top of the learning speed ‘pyramid’, yet when it’s found that we are not then we say that learning speed is not a useful measure of intelligence? Can you see the huge bias there?
Above is a figure from Mashour and Alkire (2013) which shows the evolution of the brain through the lens of the scala naturae concept on the left and the modern theory on the right. Clearly, with the modern theory, there is no such ‘progress’ or ‘inherent advancement’ from fish culminating to the brain of Man.
Modern theories of the scala naturae include John Bonner’s assertion that animals found in lower strat are ‘lower’ whereas those found in the higher strata are ‘higher’. This erroneous assumption made by Bonner, however, is corrected in subsequent publications (see Randomness in Evolution, Bonner, 2013). He stresses, as can be seen by the title of the book, that evolution is random and possibly non-drive (i.e., passive, see McShea, 1994, Gould, 1996) (Diogo, Ziermann, and Linde-Medina, 2014: 3). Furthermore, there is “no general trend to increase the number of muscles at the nodes leading to hominoids and to modern humans. That is, with respect to the muscles in the regions we have investigated, although modern humans accumulated more evolutionary transitions than the other primates included in our cladistic study, these evolutionary transitions did not result in more muscles, or more muscle components (Diogo & Wood, 2011, 2012a,b; Diogo et al., 2013b)” (Diogo, Ziermann, and Linde-Medina, 2014: 18). So looking at this one facet of hominin evolution (muscles), there is no general increase in the number of muscles at the nodes leading to our genus.
Next, one Dale Russel (who I have written about at length) needs to be addressed again. Russel asserts that had the dinosaurs not gone extinct, that one species of dinosaur, the troodon, would have evolved human-like bipedalism, a large brain among other traits. This is horribly incorrect. In his book (Russel, 1989) he denotes ever-increasing complexity, which, as I have noted, is due to the beginnings of life at the left wall of complexity. The behaviors of most dinosaurs which were inferred from skeletal morphology and trackways “may not have lain much outside the observed range in ectothermic crocodilians” (Hopson, 1977: 444), along with most dinosaur endocasts showing not showing a tendency for increased brain size (Hopson, 1977: 443). Further, since dinosaurs were tied to the sun their behavior was restricted, they needed to avoid getting too hot or cold and couldn’t explore and understand the world, and in turn wouldn’t have been able to evolve large brains—nevermind human-like intelligence (Skoyles and Sagan, 2002: 12). Russell’s contentions are moot.
On that same note, E.O. Wilson, author of the 1975 book Sociobiology asserts that evolution must be progressive (I will cover Wilson’s views on evolutionary progress in depth in the future) since life started prokaryotes with no nucleus, to eukaryotes with nucleus and mitochondria, then multi-cellular organisms with complex organs like eyes and brains and finally the emergence of the human mind (Rushton, 1997: 293). This, too, can be explained by life beginning at the left wall and having nowhere to go ‘but up’.
This finally brings me to JP Rushton who attempted to revive the scala naturae concept by (wrongfully) applying r/K selection theory to human races. Rushton argues that since Mongoloids are the ‘newest’ race that they are then the most ‘progressed’ and thusly are a pinnacle of evolution of Man. However, as anyone who understands evolution knows, evolution through natural selection is local change, not progress.
This notion of evolutionary progress, the scala naturae, and the ‘march up the evolutionary tree’ are all large misconceptions about the nature of evolution. This misconception arises due to only looking at the right tail of the variation. Of course, if you only looked at the right tail, you would assume that evolution is ‘progressive’, that there was a ‘march’ from simple to complex organisms. Why focus only on the complex end of the distribution of life? Because looking at the whole of life, bacteria is the mode (Gould, 1996; 1997). We are currently living in the age of the bacteria. That is the mode of all life, and that is why there is no ‘progress’ to evolution, nor any ‘march up an evolutionary tree’, because evolution through natural selection is local change, not progress.
Saying that evolution is progress doesn’t allow us to appreciate the full house of variation (Gould, 1996). Bacteria rule the earth, and will do so until the Sun explodes. What does that tell you about any ‘progress’ to life? Aboslutely nothing because bacteria have remained the most numerous lifeforms on the planet since life began.
What is intelligence? How would we define it? Would intelligence be reacting to what occurs in the immediate environment; having the ability to have behavioral plasticity or even communicating with others? Amazingly, bacteria have been found to do both things noted above: They have been found to be able to react to their environment, i.e., have the ability for plastic behavior and they have even been shown to communicate with one another. Hell, even something as simple as a slime mold has been found to navigate a maze to find food. Is that not intelligence?
Ken Richardson, author of the book Genes, Brains, and Human Potential: The Science and Ideology Behind Intelligence writes:
Living things, then, need to be good at registering those statistical patterns across everyday experience and then use them to shape the best response, including (in the cell) what genes to recruit for desired products. This is what intelligence is, and it’s origins coincide with the origins of life itself, and life is intelligence. (Richardson, 2017: 115)
In multicelluar systems, of course, the cells are not just responding to one another, but also collectively to the changing environment outside. That requires an intelligent physiology, as described in chapter 5. However, it is still the statistical structure of the changes that matters and that forms the basis of a living intelligence. Even at this level, closest to the genes, then, the environment is emphatically not a loose collection of independent factors to which the cells respond, in stimulus-response fashion, under gene control. This reality makes the additive statistical models of the behavioral geneticist quite unrealistic. (Richardson, 2017: 120)
Currently, our view of intelligence has an anthropometric lean. But, as I’ve been saying for months now, why should we view humans as a sort of ‘apex’ to evolution? Why should we be the measuring stick? If you really think about it to put us—our brains—at the top of a rank order as ‘the best’ and not recognize what other, smaller supposedly ‘archaic’ forms of life can do, then maybe it’s best to take off our human-centric glasses and look at the whole of the animal kingdom as intelligent—including bacteria, as they show the basic things necessary for what we would call intelligence, i.e., behavioral plasticity.
In this paper published just two months ago, the authors write:
Bacteria are far more intelligent than we can think of. They adopt different survival strategies to make their life comfortable. Researches on bacterial communication to date suggest that bacteria can communicate with each other using chemical signaling molecules as well as using ion channel mediated electrical signaling. (Majumdar and Pal, 2017)
Furthermore, looking at definitions of the term ‘behavior’ from ethology, we can see that bacteria exhibit these behaviors that we have deemed ‘human’ or ‘human-like’:
- “Externally visible activity of an animal, in which a coordinated pattern of sensory, motor and associated neural activity responds to changing external or internal conditions” (Beck et al. 1981)
- “A response to external and internal stimuli, following integration of sensory, neural, endocrine, and effector components. Behavior has a genetic basis, hence is subject to natural selection, and it commonly can be modified through experience” (Starr and Taggart 1992)
- “Observable activity of an organism; anything an organism does that involves action and/or response to stimulation” (Wallace et al. 1991)
- “What an animal does” (Raven and Johnson 1989)
Bacteria have been found to fit all of the criteria mentioned above. If organisms can react to how the environment changes, then that organism has—at least a semblance—of intelligence. Bacteria have also been found to be able to learn and they also have memories, so if this is true (and it is), then bacteria are intelligent.
Finally, Westerhoff et al (2014) write that leaving out the terms ‘human’ and our brains as measuring sticks for what is intelligent, that “all forms of life – from microbes to humans – exhibit some or all characteristics consistent with “intelligence.” For people with anthropocentric views of evolution, however, this is a hard pill to swallow. If the data says that bacteria have evidence of ‘cognition’ and an ability to react to outside environmental cues then bacteria have a semblance of intelligence. There is no denying it.
We clearly need to look at intelligence in a different way—one that’s free of any anthropocentric bias—-and if we do, we would recognize numerous species as intelligent that we would never have thought of before since we view ourselves as some sort of ‘apex’ of evolution, that we are supreme on this earth, when the bacteria—the modal bacter—reign supreme and will continue to remain supreme until the Sun explodes. So if bacteria show the ability to communicate with one another and the ability to change their behavior when their environment changes, i.e., that they learn and have ‘memories’ of past events, then maybe it’s time for us to change from our human-centric view of intelligence (which makes a ton of sense; viewing us as an ‘apex’ of evolution makes no sense and doesn’t allow us to appreciate the wide range of variation on earth).
As Gould wrote in Full House, looking at only the right tail we would believe that some sort of ‘progress’ reigns supreme, but looking at the whole sum of variation, we can see that the bacteria are the mode of all life, have been the mode of all life and will remain the mode of all life until the Sun explodes and all life forever perishes from Earth.
In part I, I showed how Dale Russel’s contention that the troodon would have evolved into a bipedal ‘dinosauroid’ with human locomotion and a human-sized brain was pure fantasy. I ordered the book of his that Rushton cited in his book Race, Evolution, and Behavior and I finally received it last week. When I read the relevant parts, I yawned because it’s the same old stuff that I’ve covered here on this blog numerous times. Since literally the only relevant part in the book about the troodon is the final 7 pages, that’s what I will cover today—along with a few more lines of evidence that large brains lie outside reptilian design (Gould, 1989).
First off, all of Rushton’s contentions in the final pages of his book (Rushton, 1997) need to be rebutted. Rushton (1997: 294) writes that dinosaur brains were ‘progressing’ in size for 140 million years, but neither of Russel’s writings that I have (Russel 1983; 1989) have the statement in them.
In the book Up From Dragons: The Evolution of Human Intelligence neuroscientist, evolutionary psychologist John Skoyles and science writer Dorian Sagan—the son of Carl Sagan—speak briefly about reptilian intelligence and why they wouldn’t have reached our levels of intellect:
But cold-bloodedness is a dead-end for the great story of this book—the evolution of intelligence. Certainly reptiles could evolve huge sizes, as they did over vast sweeps of Earth as dinosaurs. But they never could have evolved our quick-witted and smart brains. Being tied to the sun restricts their behavior: Instead of being free and active, searching and understanding the world, they spend too much time avoiding getting too hot or too cold. (Skoyles and Sagan, 2002: 12)
Hopson (1977: 443) writes:
I would argue, as does Feduccia (44), that the mammalian/avian levels of activity claimed by Bakker for dinosaurs should be correlated with a great increase in motor and sensory control and this should be reflected in increased brain size. Such an increase is not indicated by most dinosaur endocasts.
Most importantly, if some dinosaurs DID have bird-sized brains, the above contention would still hold. Hopson concludes that, except for coelurosaurs “the range of behaviors that existed in dinosaurs, as inferred from trackways and skeletal morphology, may not have lain much outside the observed range in ectothermic crocodilians” (Hopson, 1977: 444).
Since the conjecture/’thought experiment’ of the troodon was rebutted last week, it’s pretty conclusive that large brains lie outside of reptilian design; they need to spend so much time avoiding getting too hot or cold—as well as hunt and eat—so exploring the world and learning was not possible for them—along with the fact that they didn’t have a primate morphology and thus didn’t have the ability to fully manipulate their environment as we do which would further select for larger brains. However, as Hopson (1977) notes, animals with higher metabolic rates had larger brains; coelurosaurs had high metabolic rates and the largest dinosaur brains (Russel, 1983; 1989)—but that doesn’t mean they would have eventually evolved human-like intelligence, bipedalism or brain size and to say otherwise is fantasy.
Furthermore, there is large variation in encephalization and encephalization is not universal in mammals (Shultz and Dunbar, 2010).
Here is the thing about brain size increases: it is a local level trend. A local level trend is a trend that occurs within one or a few related species. This is exactly what characterized brain evolution; there is large variation depending on what the environment calls for (Boddy et al, 2012; Montgomery et al, 2012; see also island gigantism; Bromham and Cardillo, 2007; Welch, 2009; and also see the deep sea rule; Mcclain, Boyer, and Rosenberg, 2006). So these local trends differ by species—even one population split by, say, 50 miles of water will speciate and become evolve a completely different phenotype due to the environment of time. That is evolution by natural selection; local change, not any inherent or intrinsic ‘progress’ (Gould, 1996).
The same local level trend occurs with parasites. Now think about parasites. The get selected for ‘complexity’ or a decrease in ‘complexity’ depending on what occurs in their host. Now, looking at it from this perspective, the body is the host’s environment while the earth is ours; so my example for an environmental change would be, as usual, the asteroid impact hitting the earth blocking out the sun and decreasing high-quality food all throughout the earth. Surely I don’t need to tell you what would occur…
Russel (1989) writes:
Examples of evolutionary changes that occured at ever-increasing speeds include the initial diversification of animals in the sea 650 and 550 million years ago, the attainment of tree stature in land plants between 410 and 360 million years ago, and the diversification of mammals between 200 million years ago and the present. Changes like this have resulted in increased organismal complexity, which, in combination with a general increase in number of species, has made the biosphere of the modern Earth so much richer than it was several hundred million years ago. It is reasonable to suppose that animals living in a complex environment might find it advantageous to possess complex nervous systems in order to have access to a greater variety of responses. Indeed, the largest proportion of brain weight in an animal has also increased at an ever-increasing rate across geological time. The brain has become evidently larger in animals as diverse as insects, mollusks, and backboned creatures. Relative brain size can be taken as an indication of biotic interactions.
He references time periods that correspond with decimations (mass extinctions). Decimations lead to diversification. Think back to the Cambrian Explosion. During the Cambrian Explosion, many more lifeforms existed than can be currently classified. Therefore, according to the decimation and diversification model, greater diversity of life existed in the past. When decimations (defined as a reduction in the anatomical forms of life from mass extinction) occur, the niches that become extinct quickly become filled.
The time periods that Russel references are when mass extinctions occurred. This is how diversification occurs. What allowed for this ‘organismal complexity’ and increase in the number of species (though body plans are limited due to the Burgess Decimation) is due to the decimations. Decimation and diversification proves that evolution is not progressive.
A ‘trend’ in biology is directional change in a group stat using the mean, median or mode. Any existence of a trend from the mean (‘progress’) tells us nothing about the underlying mechanisms behind it.
To wrap this all up, even if a trend in X were to be discovered, it still wouldn’t tell us a thing about the underlying mechanisms causing it, nor will it tell us about any increasing tendency.
The analogy of the drunkard’s walk (Gould, 1996) is why ‘progress’ doesn’t make sense. Further, niche construction matters as well. When organisms construct their own niches, change occurs based on those niche constructions. Milk-drinking 8kya in Europe and African farmers diverting water for their crops having mosquitoes come by and gaining a resistance to malaria are two examples of niche construction (Laland et al, 2009). That’s another barrier to progress!
In sum, Dale Russel says nothing I’ve not heard before in regards to ‘progressive’ evolution. He only describes ever-increasing ‘complexity’ which is due to decimations and further diversification by organisms to fill empty niches. Any type of ‘progress’ would have been stymied by mass extinctions.
Further, the fact that species can consciously—in a way—guide their own evolution through the manipulation of the environment once again shows how evolution doesn’t mean progress—it literally only means local change and any type of local change, no matter to what type of environment, will cause concurrent increases/decreases on whichever relevant traits that will give the organism the best chance for survival in that environment.
This is why evolution is not progressive; and even if scientists were to identify one thing, still, a causal mechanism won’t be able to be inferred. Ruseel (1989) describes right and left walls of complexity—nothing more. Dinosaurs didn’t have the body plans to have our brain size, bipedalism and intelligence, nor did they have the right type of blood, nor did they have the time to search and learn about the world due to being constrained to their cold-blooded system—being a slave to the sun, always attempting to avoid overheating or getting too cold (Skoyles and Sagan, 2002). The so-called ‘dinosauroid’ is an impossibility and implies a teleological lean to evolution—as if our morphology (or something similar from an unrelated organism) will always evolve if we replay the tape of life again (Gould, 1989; 1996). This is what Russel is pretty much arguing, and he is 100 percent wrong as noted above.
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