Back in October, I wrote that floresiensis is either descended from Erectus or habilis, since those were the only two hominins in the region. Yesterday a study was published titled The affinities of Homo floresiensis based on phylogenetic analyses of cranial, dental, and postcranial characters (Argue et al, 2017), in which Argue et al argue that floresiensis was not descended from a shipwrecked Erectus, as is a popular view. Another theory is that floresiensis is descended from habilis. The third theory is that floresiensis is Homo sapiens with a pathology, but that has been disproven (Falk et al, 2009). It was commonly thought that the LB1 floresiensis specimen was a pathological human inflicted with Laron syndrome which is a type of growth hormone deficiency (Laron and Klinger, 1994).
Argue et al found that floresiensis and erectus had completely different bone structures, particularly in the pelvis and jaw. They now believe that the theory that floresiensis is a derived form of an erectus that swam or rafted to Flores has been defintively refuted. They found that floresiensis was a sister species to habilis. So either a common ancestor of floresiensis or habilis swam to Flores from Africa, or floresiensis evolved in Africa and swam to Flores. They used new phylogenetic techniques to ascertain that floresiensis is stil a part of our lineage, but shows no phylogenetic relationship to erectus on the tree.
According to Baab (2016), biogeography shows that Indonesian erectus is the best fit with what is currently known. She says if floresiensis was derived from erectus that it “implies some degree of body size reduction and more marked brain size reduction.”
Kubo, Kono, and Kaifu (2013) conclude that the evolution of floresiensis from early Javanese erectus is possible when comparing the brain cases of both specimens. However, if floresiensis descended from habilis, then the brain size reduction wouldn’t be as marked (and is still due to island dwarfism, just not on as large of a scale as it would be if floresiensis were descended from erectus). The LB1 specimen also shows the closest neural affinities to early Asian erectus (Baab, Mcnulty, and Harvati, 2013; but see Vannuci, Barron, and Holloway, 2013 for the microcephalic view). Weston and Lister, (2009) showed that there was a 30 percent reduction in brain size in Magalasy hippos, which lends credence to the insular dwarfism hypothesis for floresiensis. Craniofacial morphology also shows that floresiensis evolved from Asian erectus (Kaifu et al, 2011).
The teeth of unknown hominin found at Mata Menge are intermediate between floresiensis and erectus, being 600,000 years older than where floresiensis was found (van den Bergh et al, 2016). This lends credence to the hypothesis that floresiensis is derived from erectus. Furthermore, insular dwarfism is seen in primate species isolated on islands, with changes in body size seen in child populations even on large islands not far from the mainland (Bromham and Cardillo, 2007, Welch, 2009). Genetically isolated on islands, primates can become bigger if the parent population was smaller, or smaller if the parent population was bigger. This is due to differing energy demands relative to the parent population, along with differing predators/prey.
The island rule even holds in the deep sea. As is the case with islands, the deep sea is also associated with decreased food availability. Looking at several species of gastropods, McClain, Boyer, and Rosenberg (2006) found that the island rule held in small-bodied shallow species. They were found to have larger bodied deep-sea representatives, with the same being true for large bodied deep-sea gastropods. Further, island dwarfism in elephants on the islands Sicily, Malta, Cyprus; mammoths on the California channel islands; and red deer on the island Jersey involved body mass changes of 5- to 100-fold over 2,300 to 120,000 generations (Evans et al, 2012).
So the overall hypothesis that island dwarfism is still intact, albeit if floresiensis is derived from habilis, the reduction in brain/body size would be smaller than if floresiensis evolved from early Asian erectus.
Further evidence for brain/body size reduction due to less food availability is noted by Daniel Lieberman in his book The Story of the Human Body: Evolution, Health, and Disease (Lieberman, 2013). While talking about the evolution of floresiensis on page 123 he writes:
The same energetic constraints and processes also affect hunter-gatherers . 62
And in the 62nd footnote on page 391 he writes:
Several human “pygmy” populations (people whose height does not exceed 150 centimeters, or 4.9 feet) have evolved in energy limited places like rain forests or islands. Perhaps the small size of the Dmansi hominins from Georgia also reflected selection to save energy among the first colonists of Eurasia.
Either way, if floresiensis evolved from erectus or habilis, considerable reductions in brain size have to be explained, since the smallest erectus brain ever found is 600 cubic centimeters while the smallest habilis brain ever found is 510 cubic centimeters (Lieberman, 2013: 124), with floresiensis having a brain 417 cubic centimeters (Falk et al, 2007).
What is most important about the insular dwarfism hypothesis in regards to the evolution of floresiensis is the effect of energy reduction/food availability and quality in regards to populations isolated on islands from parent populations. Floresiensis was able to survive on about 1200 kcal by shrinking, needing to consume about 1400 kcal during lactation compared to 1800 kcal for an erectus female who needed about 2500 kcal during lactation (Lieberman, 2013: 125). The cognitive price for the reduction in the brain size of floresiensis is not known, but since brains are so energy expensive (Aiello and Wheeler, 1995; Herculano-Houzel and Kaas, 2011; Fonseca-Azevedo and Herculano-Houzel, 2012), the reduction seen in floresiensis is no surprise.
Energy is one of the most important drivers for the evolution of a species, the evolution of floresiensis is one major example of this. Whether floresiensis evolved from habilis or erectus, reduced energy on the island caused the brain and body size of floresiensis to get smaller to cope with fewer things to eat. Keep in mind that habilis was a meat-eater as well, and with lower-quality energy on the island, the brain would have to reduce in size as it’s one of the most expensive organs in the body. As I’ve been saying for a long time now, the quality of energy is most important to the evolution of a species—especially Man. Cooking was imperative to our evolution, and with a lower-quality diet, we, too, would evolve smaller brains and bodies to compensate for reduced energy consumption since our brains take 25 percent of our daily energy requirements to power despite being 2 percent of our overall body weight.
The evolution of floresiensis shows how important energy is in the evolution of species. Its biggest implication—no matter if floresiensis evolved from habilis or erectus—is how important diet quality is to evolution, as I’ve noted here, here, here, here, here, and here. Without our high-quality diet, we, too, would suffer the same body/brain size reductions that floresiensis did.
Aiello, L. C., & Wheeler, P. (1995). The Expensive-Tissue Hypothesis: The Brain and the Digestive System in Human and Primate Evolution. Current Anthropology,36(2), 199-221. doi:10.1086/204350
Argue, D., Groves, C. P., Lee, M. S., & Jungers, W. L. (2017). The affinities of Homo floresiensis based on phylogenetic analyses of cranial, dental, and postcranial characters. Journal of Human Evolution. doi:10.1016/j.jhevol.2017.02.006
Baab, K. L., Mcnulty, K. P., & Harvati, K. (2013). Homo floresiensis Contextualized: A Geometric Morphometric Comparative Analysis of Fossil and Pathological Human Samples. PLoS ONE,8(7). doi:10.1371/journal.pone.0069119
Baab, K.L. (2016). The place of Homo floresiensis in human evolution. Journal of Anthropological Sciences, 94, 5-18.
Bergh, G. D., Kaifu, Y., Kurniawan, I., Kono, R. T., Brumm, A., Setiyabudi, E., . . . Morwood, M. J. (2016). Homo floresiensis-like fossils from the early Middle Pleistocene of Flores. Nature,534(7606), 245-248. doi:10.1038/nature17999
Bromham, L., & Cardillo, M. (2007). Primates follow the ‘island rule’: implications for interpreting Homo floresiensis. Biology Letters,3(4), 398-400. doi:10.1098/rsbl.2007.0113
Evans AR, Jones D, Boyer AG, Brown JH, Costa DP, et al. (2012) The maximum rate of mammal evolution. Proc Natl Acad Sci USA 109: 4187–4190.
Falk, D., Hildebolt, C., Smith, K., Morwood, M. J., Sutikna, T., Jatmiko, … Prior, F. (2007). Brain shape in human microcephalics and Homo floresiensis. Proceedings of the National Academy of Sciences of the United States of America, 104(7), 2513–2518. http://doi.org/10.1073/pnas.0609185104
Falk, D., Hildebolt, C., Smith, K., Jungers, W., Larson, S., Morwood, M., . . . Prior, F. (2009). The type specimen (LB1) of Homo floresiensis did not have Laron Syndrome. American Journal of Physical Anthropology,140(1), 52-63. doi:10.1002/ajpa.21035
Fonseca-Azevedo, K., & Herculano-Houzel, S. (2012). Metabolic constraint imposes tradeoff between body size and number of brain neurons in human evolution. Proceedings of the National Academy of Sciences,109(45), 18571-18576. doi:10.1073/pnas.1206390109
Herculano-Houzel, S., & Kaas, J. H. (2011). Gorilla and Orangutan Brains Conform to the Primate Cellular Scaling Rules: Implications for Human Evolution. Brain, Behavior and Evolution, 77(1), 33–44. http://doi.org/10.1159/000322729
Kaifu, Y., Baba, H., Sutikna, T., Morwood, M. J., Kubo, D., Saptomo, E. W., . . . Djubiantono, T. (2011). Craniofacial morphology of Homo floresiensis: Description, taxonomic affinities, and evolutionary implication. Journal of Human Evolution,61(6), 644-682. doi:10.1016/j.jhevol.2011.08.008
Kubo, D., Kono, R. T., & Kaifu, Y. (2013). Brain size of Homo floresiensis and its evolutionary implications. Proceedings of the Royal Society B: Biological Sciences,280(1760), 20130338-20130338. doi:10.1098/rspb.2013.0338
Laron, Z., & Klinger, B. (1994). Laron Syndrome: Clinical Features, Molecular Pathology and Treatment. Hormone Research,42(4-5), 198-202. doi:10.1159/00018419
Lieberman, D. (2013). The Story of the human body – evolution, health and disease. Penguin.
Mcclain, C. R., Boyer, A. G., & Rosenberg, G. (2006). The island rule and the evolution of body size in the deep sea. Journal of Biogeography,33(9), 1578-1584. doi:10.1111/j.1365-2699.2006.01545.x
Vannucci, R. C., Barron, T. F., & Holloway, R. L. (2011). Craniometric ratios of microcephaly and LB1, Homo floresiensis, using MRI and endocasts. Proceedings of the National Academy of Sciences of the United States of America, 108(34), 14043–14048. http://doi.org/10.1073/pnas.1105585108
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Misinformation about testosterone and strength in regards to race is rampant in the HBD-o-sphere. One of the most oft-repeated phrases is that “Blacks have higher levels of testosterone than whites”, even after controlling for numerous confounds. However, the people who believe this literally only cite one singular study with 50 blacks and 50 whites. Looking at more robust data with higher ns shows a completely different story. Tonight I will, again, go through the race/testosterone conundrum (again).
Type I fibers fire first when heavy lifting. Whites have more type I fibers. Powerlifters and Olympic lifters have a greater amount type IIa fibers, with fewer type IIx fibers (like whites). This explains why blacks are hardly represented in powerlifting and strongman competitions.
Somatype, too, also plays a role. Whites are more endo than blacks who are more meso. Endomorphic individuals are stronger, on average, than mesomorphic and ectomorphic individuals.
Blacks have narrower hips and pelves. This morphological trait further explains why blacks dominate sports. Some people may attempt to pick out one variable that I speak about (fiber type, morphology, somatype, fat mass, etc) and attempt to disprove it, thinking that disproving that variable will discredit my whole argument. However, fiber typing is set by the second trimester, with no change in fiber type from age 6 to adulthood (Bell et al, 1980).
It is commonly believed that blacks have higher levels of testosterone than whites. However, this claim is literally based off of one study (Ross et al, 1986) when other studies have shown low to no difference in T levels (Richards et al, 1992; Gapstur et al, 2002; Rohrmann et al, 2007; Mazur, 2009; Lopez et al, 2013; Richard et al 2014). People who still push the “blacks-have-higher-T-card” in the face of this evidence are, clearly, ideologues who want to cushion their beliefs when presented with contradictory evidence (Nyhan and Reifler, 2010).
‘Honor Culture’ and testosterone
In all of my articles on this subject, I have stated—extensively—that testosterone is mediated by the environment. That is, certain social situations can increase testosterone. This is a viewpoint that I’ve emphatically stated. I came across a paper while back that talks about a sociological perspective (I have huge problems with social ‘science’, [more on that soon] but this study was very well done) in regards to the testosterone difference between blacks and whites.
Some people when they read this, however, may go immediately to the part of the paper that says what they want it to say without fully assessing the paper. In this section, I will explain the paper and how it confirms my assertions/arguments.
Mazur (2016) begins the paper talking about ‘honor culture‘, which is a culture where people avoid intentionally offending others while also maintaining a status for not backing down from a confrontation. This theory was proposed by Richard Nisbett in 1993 to explain why the South had higher rates of violence—particularly the Scotch-Irish.
However parsimonious the theory may sound, despite its outstanding explanatory power, it doesn’t hold while analyzing white male homicides in the South. It also doesn’t hold analyzing within-county homicide rates either, since apparently poverty better explains higher homicide rates.
But let’s assume it’s true for blacks. Let’s assume the contention to be true that there is an ‘honor culture’ that people take part in.
Young black men with no education had higher levels of testosterone than educated whites and blacks. Looking at this at face value—literally going right to the section of the paper that says that poor blacks had higher testosterone, nearly 100 ng/ml higher than the mean testosterone of whites. As Mazur (2016) notes, this contradicts his earlier 2009 study in which he found no difference in testosterone between the races.
Note the low testosterone for both races at age 20-29—ranging from about 515 to 425—why such low testosterone levels for young men? Anyway, the cause for the higher levels is due to the type of honor culture that blacks participate in, according to Mazur (which is consistent with the data showing that testosterone rises during conflict/aggressive situations).
Mazur cites Elijah Anderson, saying that most youths have a “code of the streets” they take part in, which have to do with interpersonal communication such as “gait and verbal expressions” to deter aggressive behavior.
Testosterone is not a causal variable in regards to violent behavior. But it does rise during conflicts with others, watching a favorite sports team, asserting dominance, and even how you carry yourself (especially your posture). Since low-class blacks participate in these types of behaviors, then they would have higher levels of testosterone due to needing to “keep their status.”
When testosterone rises in these situations, it increases the response threat in mens’ brains, most notably showing increased activity in the amygdala. Further, dominant behavior and posture also increase testosterone levels. Putting this all together, since blacks with only a high school education have higher testosterone levels and are more likely to participate in honor culture compared to whites and blacks with higher educational achievement, then they would have higher testosterone levels than whites and blacks with a high school education who do not participate in honor culture.
Further, as contrary to what I have written in the past (and have since rescinded), there is no indication of higher testosterone levels in black women with low education. It seems this ‘honor culture’ effect on testosterone only holds for black men with only a high school education.
Mazur’s (2016) most significant finding was that black men aged 20-29 with only a high school education had 91 ng/ml higher testosterone than whites. Among older and/or educated men, testosterone did not vary. This indicates that since they have attained higher levels of educational success, there is no need to participate in ‘honor culture’.
This is yet further evidence for my assertion that environmental variables such as posture, dominance, and aggressive behavior raise testosterone levels.
The honor culture hypothesis is found to hold in Brazil in a comparative study of 160 inmates and non-inmates (De Souza et al, 2016). As Mazur (2016) notes, the honor culture hypothesis could explain the high murder rate for black Americans—the need to ‘keep their status’. It’s important to note that this increase in testosterone was not noticed in teenage or female blacks (because they don’t participate in honor culture).
There is a perfectly good environmental—not genetic—reason for this increase in testosterone in young blacks with only a high school education. Now that we know this, back to race and strength.
Mazur (2009) found that black men in the age range of 20-69, they averaged .39 ng/ml higher testosterone than whites, which is partly explained by lower marriage rates and low adiposity. White men are more likely to be obese than black men, since black men with more African ancestry are less likely to be obese. When controlling for BMI, blacks are found to have 2.5-4.9 percent more testosterone than whites (Gapstur et al, 2002, Rohrmann et al, 2007, Richard et al, 2014). There is little evidence for the assertion that blacks have higher levels of testosterone without environmental triggers.
Blacks between the age of 12 and 15 average lower levels of testosterone than whites. However, after the age of 15, “testosterone levels increase rapidly” with blacks having higher peak levels than whites (seen in table 2 below). After adjusting for the usual confounds (BMI, smoking, age, physical activity, and waist circumference), blacks still had higher levels of testosterone—which is attributed to higher levels of lean mass.
As seen above in table 2 from Hu et al (2014), the difference in total testosterone between blacks and whites aged 20-39 was 6.29 ng/ml and 5.04 ng/ml respectively, with free testosterone for whites being 11.50 and 13.56 for blacks and finally bioavailable testosterone for whites and blacks aged 20-39 was 281.23 and 327.18 ng/ml respectively. These small differences in testosterone cannot account for racial disparities in violence nor prostate cancer—since there is no relationship between prostate cancer and testosterone (Stattin et al, 2003; Michaud, Billups, and Partin, 2015).
In regards to Africans, the best studies I can find comparing some African countries with the West study salivary testosterone. However, there is a direct correlation between salivary testosterone and free serum testosterone (Wang et al, 1981; Johnson, Joplin, and Burrin, 1987). Of the studies I could find, Kenyan pastoralists called the Ariaal have lower levels of testosterone than Western men (Campbell, O’Rourke, and Lipson, 2003; Campbell, Gray, and Ellison, 2006) while men in Zimbabwe had levels “much lower” compared to Western populations (Lukas, Campbell, and Ellison, 2004). Lastly, among men aged 15 to 30, salivary testosterone levels in an American sample was 335 pmol//l compared to 286 pmol/l in men from the Congo (Elisson et al, 2002). Even certain African populations don’t have higher testosterone levels than Western peoples.
The meme that blacks have higher rates of testosterone in comparison to whites needs to be put to rest. This is only seen in blacks who participate in ‘honor culture’, which is an environmental variable. This is in contrast to people who believe that it is genetic in nature—environmental variables can and do drive hormones. Mazur (2016) is proof of that. Mazur (2016) also shows that the honor culture hypothesis doesn’t hold for teens or black males—so they don’t have elevated levels of testosterone. Certain studies of African populations, however, do not show higher levels of testosterone than Western populations.
Looking at the complete literature—rather than a select few studies— we can see that testosterone levels between white and black Americans are not as high as is commonly stated (Richards et al, 1992; Gapstur et al, 2002; Rohrmann et al, 2007; Mazur, 2009; Lopez et al, 2013; Hu et al, 2014; Richard et al, 2014). Further, even if blacks did have higher levels of testosterone than whites—across the board (sans honor culture), it still wouldn’t explain higher rates of black violence when compared to whites, nor would it explain higher prostate cancer rates (Stattin et al, 2003; Michaud, Billups, and Partin, 2015).
Only blacks with low educational achievement have higher levels of testosterone—which, even then is not enough to explain higher rates of violence or prostate cancer acquisition. Other factors explain the higher murder rate (i.e., honor culture, which increases testosterone, the environmental trigger matters first and foremost) and violent crime that blacks commit. But attempting to explain it with 30-year-old studies (Ross et al, 1986) and studies that show that environmental factors increase testosterone (Mazur, 2016) don’t lend credence to that hypothesis.
Bell, R. D., Macdougall, J. D., Billeter, R., & Howald, H. (1980). Muscle fiber types and morphometric analysis of skeletal muscle in six-year-old children. Medicine & Science in Sports & Exercise,12(1). doi:10.1249/00005768-198021000-00007
Campbell, B., O’rourke, M. T., & Lipson, S. F. (2003). Salivary testosterone and body composition among Ariaal males. American Journal of Human Biology,15(5), 697-708. doi:10.1002/ajhb.10203
Campbell, B. C., Gray, P. B., & Ellison, P. T. (2006). Age-related patterns of body composition and salivary testosterone among Ariaal men of Northern Kenya. Aging Clinical and Experimental Research,18(6), 470-476. doi:10.1007/bf03324846
De Souza, Souza, B. C., Bilsky, W., & Roazzi, A. (2016). The culture of honor as the best explanation for the high rates of criminal homicide in Pernambuco: A comparative study with 160 convicts and non-convicts. Anuario de Psicología Jurídica,26(1), 114-121. doi:10.1016/j.apj.2015.03.001
Ellison, P. T., Bribiescas, R. G., Bentley, G. R., Campbell, B. C., Lipson, S. F., Panter-Brick, C., & Hill, K. (2002). Population variation in age-related decline in male salivary testosterone. Human Reproduction,17(12), 3251-3253. doi:10.1093/humrep/17.12.3251
Serum androgen concentrations in young men: a longitudinal analysis of associations with age, obesity, and race—the CARDIA male hormone study. Cancer Epidemiol Biomarkers Prev 2002; 11: 1041–7, , , , , .
Hu, H., Odedina, F. T., Reams, R. R., Lissaker, C. T., & Xu, X. (2014). Racial Differences in Age-Related Variations of Testosterone Levels Among US Males: Potential Implications for Prostate Cancer and Personalized Medication. Journal of Racial and Ethnic Health Disparities,2(1), 69-76. doi:10.1007/s40615-014-0049-8
Johnson, S. G., Joplin, G. F., & Burrin, J. M. (1987). Direct assay for testosterone in saliva: Relationship with a direct serum free testosterone assay. Clinica Chimica Acta,163(3), 309-318. doi:10.1016/0009-8981(87)90249-x
Lopez, D. S., Peskoe, S. B., Joshu, C. E., Dobs, A., Feinleib, M., Kanarek, N., . . . Platz, E. A. (2013). Racial/ethnic differences in serum sex steroid hormone concentrations in US adolescent males. Cancer Causes & Control,24(4), 817-826. doi:10.1007/s10552-013-0154-8
Lukas, W. D., Campbell, B. C., & Ellison, P. T. (2004). Testosterone, aging, and body composition in men from Harare, Zimbabwe. American Journal of Human Biology,16(6), 704-712. doi:10.1002/ajhb.20083
Mazur, A. (2009). The age-testosterone relationship in black, white, and Mexican-American men, and reasons for ethnic differences. The Aging Male,12(2-3), 66-76. doi:10.1080/13685530903071802
Mazur, A. (2016). Testosterone Is High among Young Black Men with Little Education. Frontiers in Sociology,1. doi:10.3389/fsoc.2016.00001
Michaud, J. E., Billups, K. L., & Partin, A. W. (2015). Testosterone and prostate cancer: an evidence-based review of pathogenesis and oncologic risk. Therapeutic Advances in Urology,7(6), 378-387. doi:10.1177/1756287215597633
Nyhan, B., & Reifler, J. (2010). When Corrections Fail: The Persistence of Political Misperceptions. Political Behavior,32(2), 303-330. doi:10.1007/s11109-010-9112-2
Richard, A., Rohrmann, S., Zhang, L., Eichholzer, M., Basaria, S., Selvin, E., . . . Platz, E. A. (2014). Racial variation in sex steroid hormone concentration in black and white men: a meta-analysis. Andrology,2(3), 428-435. doi:10.1111/j.2047-2927.2014.00206.x
Richards, R. J., Svec, F., Bao, W., Srinivasan, S. R., & Berenson, G. S. (1992). Steroid hormones during puberty: racial (black-white) differences in androstenedione and estradiol–the Bogalusa Heart Study. The Journal of Clinical Endocrinology & Metabolism,75(2), 624-631. doi:10.1210/jcem.75.2.1639961
Rohrmann, S., Nelson, W. G., Rifai, N., Brown, T. R., Dobs, A., Kanarek, N., . . . Platz, E. A. (2007). Serum Estrogen, But Not Testosterone, Levels Differ between Black and White Men in a Nationally Representative Sample of Americans. The Journal of Clinical Endocrinology & Metabolism,92(7), 2519-2525. doi:10.1210/jc.2007-0028
Ross R, Bernstein L, Judd H, Hanisch R, Pike M, Henderson B. Serum testosterone levels in healthy young black and white men. J Natl Cancer Inst. 1986 Jan;76(1):45–48
Stattin, P., Lumme, S., Tenkanen, L., Alfthan, H., Jellum, E., Hallmans, G., . . . Hakama, M. (2003). High levels of circulating testosterone are not associated with increased prostate cancer risk: A pooled prospective study. International Journal of Cancer,108(3), 418-424. doi:10.1002/ijc.11572
Wang, C., Plymate, S., Nieschlag, E., & Paulsen, C. A. (1981). Salivary Testosterone in Men: Further Evidence of a Direct Correlation with Free Serum Testosterone. The Journal of Clinical Endocrinology & Metabolism,53(5), 1021-1024. doi:10.1210/jcem-53-5-1021
Why do people deny evolution? Not just evolution from single-celled organisms to multicellular lifeforms, but human evolution as well? Most people who deny evolution don’t have the knowledge to assess it correctly. They fall back on the Bible and say “God did this, the Bible says…. God says…” all the while looking at you as a heathen when you attempt to talk some basic biology or, God forbid, the process of evolution.
I met a woman the other day and I asked her what she was studying in school. She tells me anatomy and physiology (right up my alley). So we start talking about some basic anatomy and physiology before I ask the question: “Do you believe in evolution?” She gave me a blank stare and said no.
“Humans as we know them have always existed in this form,” she said. I just started laughing at her ignorance and then she said “Evolution at the macro level is not possible but it is at the micro level”, repeating the same old and tired Creationist talking points. I said to her that there is no evidence for creation and that the evidence we do have points to evolution. I said that the theory of evolution has so much backing, so much evidence, that to believe otherwise you’d have to purposefully close your mind to the truth, to shut out any and all contradictory information.
One of the funniest things she said to me was that she wants to cure diseases. To that, I said if she wants to do that then she must look at diseases from an evolutionary perspective (Gluckman et al, 2011). She said that she doesn’t need to know how diseases were in the past, just how they are today. I also said that if she is studying anatomy and physiology then she must understand that many of our appendages are derived from our hominin ancestors, which began with Erectus as I’ve covered in my article Man the Athlete. Diseases also must be looked at through an evolutionary lens, so if anyone wants to cure diseases, then they must first understand and accept that things are constantly changing and evolving to better survive in that environment.
When I said that there is no evidence for Creation she got really mad. She said that there is no evidence that “we evolved from monkeys” which gave me a good laugh. Even people who believe in evolution still make that mistake of believing that we evolved from monkeys. One of the most common statements from Creationists is “If humans evolved from monkeys then why are monkeys still around?”, wrongly assuming that we literally evolved from monkeys, incorrectly misinterpreting that we share a common ancestor with monkeys 6-12 mya.
About 6mya, there was a chromosomal fusion on chromosome two; two ancestral ape chromosomes fused to make chromosome two (Idjo et al, 1991). That is some nice chromosomal evidence for common descent from our ape cousins. Creationists, however, purport that a gene in chromosome 2, DDX11L2, writing that the “alleged fusion site is not a degenerate fusion sequence but is and, since creation, has been a functional feature in an important gene.” Further, Tomkins’ claim that the fusion site is actually a gene is wrong since the fusion site is more than 1300 bases away from the gene.
The ancestral equivalents of chromosome 2—2p and 2q—fused together in a fusion event some 6mya. This precise fusion site is on chromosome 2 (Hellier et al, 2004). Creationists will say and do anything to attempt to ‘rebut’ this contention. Genetic evidence is the best evidence we have (due to Punctuated Equilibria, which causes the spottiness in the fossil record), and still, these ‘Creationist geneticists’ will do anything they can to attempt to have Evolutionists go on the defensive. However, the onus is on them to disprove the mountains of evidence.
One of the funniest things this woman said to me is that man has always been in this form and that we didn’t evolve from “monkeys”, which is when I said that it’s more complicated than that: we have fish ancestors, named Tiktaalik who had the beginnings of the human arm and hand, along with Pikaia Gracilens—our oldest ancestor. If Pikaia would have died out in the Cambrian explosion some 550 mya, we wouldn’t be here today. We are here today due to the happenstance of numerous accidents of history—contingencies of “just history” to quote Stephen Jay Gould.
Nevertheless, Creationists will always attempt to distort evolutionary science to fit their agendas. Stephen Jay Gould battled Creationists throughout his career. Creationists would quote mine his books to show that Evolutionists do show evidence of “Creation”. One of his most quote mined works is his and Eldredge’s theory of Punctuated Equilibria (1972). Just because a look at the whole fossil record shows species remaining in stasis for most of their history before a short burst of evolutionary change then that must mean that there was a guiding hand involved in the process. Here is a full list of quote mines that Creationists use from Eldredge and Gould.
As you can see, Creationists use any kind of mental gymnastics to disprove evolution. However, no matter how hard you try with Creationists, you can’t educate people into believing in evolution. This is mainly due to the backfire effect which occurs when you show people contradictory information to a dearly held belief and they frantically attempt to gather evidence to shield themselves from contradictory evidence (Nyhan and Reifler, 2010). This cognitive bias holds for more than political debates, though it’s most often seen there. Showing people any kind of contradictory information will have them search and search for anything to shield themselves from the truth. However, no amount of ‘information’ provided by Creationists will disprove evolutionary theory.
Gould and Eldredge aren’t the only Evolutionist that Creationists quote mine–one of the most famous quote mines is from Darwin’s The Descent of Man in which he talks about defending his theory from detractors, mainly the spottiness of the fossil record (which Eldredge and Gould’s Punctuated Equilibria explains). However, this doesn’t stop Creationists—and even some Evolutionists who fall for Creationist trickery—to believe that Darwin was talking about something completely different, in that Darwin was ‘racist’ talking about the ‘superior races’ exterminating the ‘inferior races’. Reading the quote in its entirety, however, shows something completely different. Alas, some people don’t care about facts antruthut and only care about their agenda they attempt to push.
Even setting evolutionary theory aside, basic geology disproves Creationism. The author of the piece, geologist David Montgomery, says that there is a rock outside of his office that proves Creationism wrong. The rock shows that there is more to the geologic record that could be explained by a single grand flood. Now that geologists now have the tools and data to infer that the earth is billions of years old—not thousands as Young Earth Creationists (YECs) claim—YECs change up their interpretation of the Creation story in Genesis to go from literal days to “days in Genesis refer to geological ages”. Clear mental gymnastics in the face of contradictory evidence.
There are five mass extinctions that are accepted in the scientific community (Jablonski, 2001) (though I am reading a book at the moment that talks about nine mass extinction events with Man pushing the tenth, I will return to this in the future). After these contingencies of ‘just history’, we can see that we are incredibly lucky that our ancestors did not die out. From a Pikaia Gracilens surviving the Cambrian radiation, to Tiktaalik and its venturing onto land from the sea and finally the survival of a shrew-like ancestor during the extinction of the dinosaurs, we should thank our lucky stars that these things went our way, because if not, I wouldn’t be sitting here writing this at the moment and you would not be reading this. Evolutionary history is littered with these events—events that, if they went the other way would not lead to the evolution of Man again.
In sum, people who do not believe in evolutionary theory clearly are emotionally invested in believing in a story of Creation—sans evidence, only their belief. On the other hand, evolutionists such as we have all the data on our side when it comes to this debate. Creationists have to use any kind of warped logic to not believe the mountains of evidence that have piled up since Darwin wrote On the Origin. However, as everyone knows, reality isn’t what just what you believe. Just because Creationists handwave away the data that people like us provide to them doesn’t mean that evolution isn’t true.
Human skin variation comes down to how much UV radiation a population is exposed to. Over time, this leads to changes in genetic expression. If that new genotype is advantageous in that environment, it will get selected for. To see how human skin variation evolved, we must first look to chimpanzees since they are our closest relative.
The evolution of black skin
Humans and chimps diverged around 6-12 mya. Since we share 99.8 percent of our genome with them, it’s safe to say that when we diverged, we had pale skin and a lot of fur on our bodies (Jablonski and Chaplin, 2000). After we lost the fur on our bodies, we were better able to thermoregulate, which then primed Erectus for running (Liberman, 2015). The advent of fur loss coincides with the appearance of sweat glands in Erectus, which would have been paramount for persistence hunting in the African savanna 1.9 mya, when a modern pelvis—and most likely a modern gluteus maximus—emerged in the fossil record (Lieberman et al, 2006). This sets the stage for one of the most important factors in regards to the ability to persistence hunt—mainly, the evolution of dark skin to protect against high amounts of UV radiation.
After Erectus lost his fur, the unforgiving UV radiation beamed down on him. Selection would have then occurred for darker skin, as darker skin protects against UV radiation. Dark skin in our genus also evolved between 1 and 2 mya. We know this since the melanocortin 1 receptor promoting black skin arose 1-2 mya, right around the time Erectus appeared and lost its fur (Lieberman, 2015).
However, other researchers reject Greaves’ explanation for skin cancer being a driver for skin color (Jablonksi and Chaplin, 2014). They cite Blum (1961) showing that skin cancer is acquired too late in life to have any kind of effect on reproductive success. Skin cancer rates in black Americans are low compared to white Americans in a survey from 1977-8 showing that 30 percent of blacks had basal cell carcinoma while 80 percent of whites did (Moon et al, 1987). This is some good evidence for Greaves’ hypothesis; that blacks have less of a rate of one type of skin cancer shows its adaptive benefits. Black skin evolved due to the need for protection from high levels of UVB radiation and skin cancers.
Highly melanized skin also protects against folate destruction (Jablonksi and Chaplin, 2000). As populations move away from high UV areas, the selective constraint to maintain high levels of folate by blocking high levels of UV is removed, whereas selection for less melanin prevails to allow enough radiation to synthesize vitamin D. Black skin is important near the equator to protect against folate deficiency. (Also see Nina Jablonski’s Ted Talk Skin color is an illusion.)
The evolution of white skin
The evolution of white skin, of course, is much debated as well. Theories range from sexual selection, to diet, to less UV radiation. All three have great explanatory power, and I believe that all of them did drive the evolution of white skin, but with different percentages.
The main driver of white skin is living in colder environments with fewer UV rays. The body needs to synthesize vitamin D, so the only way this would occur in areas with low UV rays.
White skin is a recent trait in humans, appearing only 8kya. A myriad of theories have been proposed to explain this, from sexual selection (Frost, 2007), which include better vitamin D synthesis to ensure more calcium for pregnancy and lactation (which would then benefit the intelligence of the babes) (Jablonski and Chaplin, 2000); others see light skin as the beginnings of more childlike traits such as smoother skin, a higher pitched voice and a more childlike face which would then facilitate less aggressiveness in men and more provisioning (Guthrie, 1970; from Frost, 2007); finally, van den Berghe and Frost (1986) proposed that selection for white skin involved unconscious selection by men for lighter-skinned women which is used “as a measure of hormonal status and thus childbearing potential” (Frost, 2007). The three aforementioned hypotheses have sexual selection for lighter skin as a proximate cause, but the ultimate cause is something completely different.
The hypothesis that white skin evolved to better facilitate vitamin D synthesis to ensure more calcium for pregnancy and lactation makes the most sense. Darker-skinned individuals have a myriad of health problems outside of their ancestral climate, one of which is higher rates of prostate cancer due to lack of vitamin D. If darker skin is a problem in cooler climates with fewer UV rays, then lighter skin, since it ensures better vitamin D synthesis, will be selected for. White skin ensures better and more vitamin D absorption in colder climates with fewer UV rays, therefore, the ultimate cause of the evolution of white skin is a lack of sunlight and therefore fewer UV rays. This is because white skin absorbs more UV rays which is better vitamin D synthesis.
Peter Frost believes that Europeans became white 11,000 years ago. However, as shown above, white skin evolved around 8kya. Further, contrary to popular belief, Europeans did not gain the alleles for white skin from Neanderthals (Beleza et al, 2012). European populations did not lose their dark skin immediately upon entering Europe—and Neanderthal interbreeding didn’t immediately confer the advantageous white skin alleles. There was interbreeding between AMH and Neanderthals (Sankararaman et al, 2014). So if interbreeding with Neanderthals didn’t infer white skin to proto-Europeans, then what did?
A few alleles spreading into Europe that only reached fixation a few thousand years ago. White skin is a relatively recent trait in Man (Beleza et al, 2012). People assume that white skin has been around for a long time, and that Europeans 40,000 ya are the ancestors of Europeans alive today. That, however, is not true. Modern-day European genetic history began about 6,500 ya. That is when the modern-day European phenotype arose—along with white skin.
Furthermore, Eurasians were still a single breeding population 40 kya, and only diverged recently, about 25,000 to 40,000 ya (Tateno et al, 2014). The alleles that code for light skin evolved after the Eurasian divergence. Polymorphisms in the genes ASIP and OCA2 may code for dark and light skin all throughout the world, whereas SLC24A5, MATP, and TYR have a predominant role in the evolution of light skin in Europeans but not East Asians, which suggests recent convergent evolution of a lighter pigmentation phenotype in European and East Asian populations (Norton et al, 2006). Since SLC24A5, MATP, and TYR are absent in East Asian populations, then that means that East Asians evolved light skin through completely different mechanisms than Europeans. So after the divergence of East Asians and Europeans from a single breeding population 25-40kya, there was convergent evolution for light pigmentation in both populations with the same selection pressure (low UV).
Some populations, such as Arctic peoples, don’t have the skin color one would predict they should have based on their ancestral environment. However, their diets are high in shellfish which is high in vitamin D, which means they can afford to remain darker-skinned in low UV areas. UV rays reflect off of the snow and ice in the summer and their dark skin protects them from UV light.
Black-white differences in UV absorption
If white skin evolved to better synthesize vitamin D with fewer (and less intense) UV rays, then those with blacker skin would need to spend a longer time in UV light to synthesize the same amount of vitamin D. Skin pigmentation, however, is negatively correlated with vitamin D synthesis (Libon, Cavalier, and Nikkels, 2013). Black skin is less capable of vitamin D synthesis. Furthermore, blacks’ skin color leads to an evolutionary environmental mismatch. Black skin in low UV areas is correlated with rickets (Holick, 2006), higher rates of prostate cancer due to lower levels of vitamin D (Gupta et al, 2009; vitamin D supplements may also keep low-grade prostate cancer at bay).
Libon, Cavalier, and Nikkels, (2013) looked at a few different phototypes (skin colors) of black and white subjects. The phototypes they looked at were II (n=19), III (n=1), and VI (n-11; whites and blacks respectively). Phototypes are shown in the image below.
To avoid the influence of solar UVB exposure, this study was conducted in February. On day 0, both the black and white subjects were vitamin D deficient. The median levels of vitamin D in the white subjects was 11.9 ng/ml whereas for the black subjects it was 8.6 ng/ml—a non-statistically significant difference. On day two, however, concentrations of vitamin D in the blood rose from 11.9 to 13.3 ng/ml—a statistically significant difference. For the black cohort, however, there was no statistically significant difference in vitamin D levels. On day 6, levels in the white subjects rose from 11.6 to 14.3 ng/ml whereas for the black subjects it was 8.6 to 9.57 ng/ml. At the end of day 6, there was a statistically significant difference in circulating vitamin D levels between the white and black subjects (14.3 ng/ml compared to 9.57 ng/ml).
Different phototypes absorb different amounts of UV rays and, therefore, peoples with different skin color absorb different levels of vitamin D. Lighter-skinned people absorb more UV rays than darker-skinned people, showing that white skin’s primary cause is to synthesize vitamin D.
UVB exposure increases vitamin D production in white skin, but not in black skin. Pigmented skin, on the other hand, hinders the transformation of 7-dehydrocholesterol to vitamin D. This is why blacks have higher rates of prostate cancer—they are outside of their ancestral environment and what comes with being outside of one’s ancestral environment are evolutionary mismatches. We have now spread throughout the world, and people with certain skin colors may not be adapted for their current environment. This is what we see with black Americans as well as white Americans who spend too much time in climes that are not ancestral to them. Nevertheless, different-colored skin does synthesize vitamin D differently, and knowledge of this will increase the quality of life for everyone.
Even the great Darwin wrote about differences in human skin color. He didn’t touch human evolution in On the Origin of Species (Darwin, 1859), but he did in his book Descent of Man (Darwin, 1871). Darwin talks about the effects of climate on skin color and hair, writing:
It was formerly thought that the colour of the skin and the character of the hair were determined by light or heat; and although it can hardly be denied that some effect is thus produced, almost all observers now agree that the effect has been very small, even after exposure during many ages. (Darwin, 1871: 115-116)
Darwin, of course, championed sexual selection as the cause for human skin variation (Darwin, 1871: 241-250). Jared Diamond has the same view, believing that natural selection couldn’t account for hair loss, black skin and white skin weren’t products of natural selection, but female mate preference and sexual selection (Greaves, 2014).
Parental selection for white skin
Judith Rich Harris, author of the book The Nurture Assumption: Why Kids Turn Out the Way They Do (Harris, 2009), posits another hypothesis for the evolution of light skin for those living in northern latitudes—parental selection. This hypothesis may be controversial to some, as it states that dark skin is not beautiful and that white skin is.
Harris posits that selection for lighter skin was driven by sexual selection, but states that parental selection for lighter skin further helped the fixation of the alleles for white skin in northern populations. Neanderthals were a furry population, as they had no clothes, so, logic dictates that if they didn’t have clothes then they must have had some sort of protection against the cold Ice Age climate, therefore they must have had fur.
Harris states that since lighter skin is seen as more beautiful than darker skin, then if a woman birthed a darker/furrier babe than the mother would have committed infanticide. Women who birth at younger ages are more likely to commit infanticide, as they still have about twenty years to birth a babe. On the other hand, infanticide rates for mothers decrease as she gets older—because it’s harder to have children the older you get.
Harris states that Erectus may have been furry up until 2 mya, however, as I’ve shown, Erectus was furless and had the ability to thermoregulate—something that a hairy hominin was not able to do (Lieberman, 2015).
There is a preference for lighter-skinned females all throughout the world, in Africa (Coetzee et al, 2012); China and India (Naidoo et al, 2016; Dixson et al, 2007); and Latin America and the Philipines (Kiang and Takeuchi, 2009). Light skin is seen as attractive all throughout the world. Thus, since light skin allows better synthesize of vitamin D in colder climes with fewer UV rays, then there would have been a myriad of selective pressures to push that along—parental selection for lighter-skinned babes being one of them. This isn’t talked about often, but infanticide and rape have both driven our evolution (more on both in the future).
Harris’ parental selection hypothesis is plausible, and she does use the right dates for fur loss which coincides with the endurance running of Erectus and how he was able to thermoregulate body heat due to lack of fur and more sweat glands. This is when black skin began to evolve. So with migration into more northerly climes, lighter-skinned people would have more of an advantage than darker-skinned people. Infanticide is practiced all over the world, and is caused—partly—by a mother’s unconscious preferences.
Skin color and attractiveness
Lighter skin is seen as attractive all throughout the world. College-aged black women find lighter skin more attractive (Stephens and Thomas, 2012). It is no surprise that due to this, a lot of black women lighten their skin with chemicals.
In a sample of black men, lighter-skinned blacks were more likely to perceive discrimination than their darker-skinned counterparts (Uzogara et al, 2014). Further, in appraising skin color’s effect on in-group discrimination, medium-skinned black men perceived less discrimination than lighter- and darker-skinned black men. Lastly—as is the case with most studies—this effect was particularly pronounced for those in lower SES brackets. Speaking of SES, lighter-skinned blacks with higher income had lower blood pressure than darker-skinned blacks with higher income (Sweet et al, 2007). The authors conclude that a variety of psychosocial stress due to discrimination must be part of the reason why darker-skinned blacks with a high SES have worse blood pressure—but I think there is something else at work here. Darker skin on its own is associated with high blood pressure (Mosley et al, 2000). I don’t deny that (perceived) discrimination can and does heighten blood pressure—but the first thing that needs to be looked at is skin color.
Lighter-skinned women are seen as more attractive (Stephen et al, 2009). This is because it signals fertility, femininity, and youth. One more important thing it signals is the ability to carry a healthy child to term since lighter skin in women is associated with better vitamin D synthesis which is important for a growing babe.
Skin color and intelligence
There is a high negative correlation between skin color and intelligence, about –.92 (Templer and Arikawa, 2006). They used the data from Lynn and Vanhanen’s 2002 book IQ and the Wealth of Nations and found that there was an extremely strong negative correlation between skin color and IQ. However, data wasn’t collected for all countries tested and for half of the countries the IQs were ‘estimated’ from other surrounding countries’ IQs.
Jensen (2006) states that the main limitation in the study design of Arikawa and Templer (2006) is that “correlations obtained from this type of analysis are completely non-informative regarding any causal or functional connection between individual differences in skin pigmentation and individual differences in IQ, nor are they informative regarding the causal basis of the correlation, e.g., simple genetic association due to cross-assortative mating for skin color and IQ versus a pleiotropic correlation in which both of the phenotypically distinct but correlated traits are manifested by one and the same gene.”
Lynn (2002) purported to find a correlation of .14 in a representative sample of American blacks (n=430), concluding that the proportion of European genes in African Americans dictates how intelligent that individual black is. However, Hill (2002) showed that when controlling for childhood environmental factors such as SES, the correlation disappears and therefore, a genetic causality cannot be inferred from the data that Lynn (2002) used.
Since Lynn found a .14 correlation between skin color and IQ in black Americans, that means that only .0196 percent of the variation in IQ within black American adults can be explained by skin color. This is hardly anything to look at and keep in mind when thinking about racial differences in IQ.
However, other people have different ideas. Others may say that since animal studies find that lighter animals are less sexually active, are less aggressive, have a larger body mass, and greater stress resistance. So since this is seen in over 40 species of vertebrate, some fish species, and over 30 bird species (Rushton and Templer, 2012) that means that it should be a good predictor for human populations. Except it isn’t.
we know the genetic architecture of pigmentation. that is, we know all the genes (~10, usually less than 6 in pairwise between population comparisons). skin color varies via a small number of large effect trait loci. in contrast, I.Q. varies by a huge number of small effect loci. so logically the correlation is obviously just a correlation. to give you an example, SLC45A2 explains 25-40% of the variance between africans and europeans.
long story short: it’s stupid to keep repeating the correlation between skin color and I.Q. as if it’s a novel genetic story. it’s not. i hope don’t have to keep repeating this for too many years.
Finally, variation in skin color between human populations are primarily due to mutations on the genes MC1R, TYR, MATP (Graf, Hodgson, and Daal, 2005), and SLC24A5 (also see Lopez and Alonso, 2014 for a review of genes that account for skin color) so human populations aren’t “expected to consistently exhibit the associations between melanin-based coloration and the physiological and behavioural traits reported in our study” (Ducrest, Keller, and Roulin, 2008). Talking about just correlations is useless until causality is established (if it ever is).
The evolution of human skin variation is complex and is driven by more than one variable, but some are stronger than others. The evolution of black skin evolved—in part—due to skin cancer after we lost our fur. White skin evolved due to sexual selection (proximate cause) and to better absorb UV rays for vitamin D synthesis in colder climes (the true need for light skin in cold climates). Eurasians split around 40kya, and after this split both evolved light skin pigmentation independently. As I’ve shown, the alleles that code for skin color between blacks and whites don’t account for differences in aggression, nor do they account for differences in IQ. The genes that control skin color (about a dozen) pale in comparison to the genes that control intelligence (thousands of genes with small effects). Some other hypotheses for the evolution of white skin are on par with being as controversial as the hypothesis that skin color and intelligence co-evolved—mainly that mothers would kill darker-skinned babies because they weren’t seen as beautiful as lighter-skinned babies.
The evolution of human skin variation is extremely interesting with many competing hypotheses, however, to draw wild conclusions based on just correlations in regards to human skin color and intelligence and aggression, you’re going to need more evidence than just correlations.
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Problems With Forensic Facial “Reconstruction”: Implications for the Facial “Reconstruction” of Ancient Hominin
Forensic facial reconstruction is the process by which a face is reconstructed from a deceased individual’s “skeletal remains through an amalgamation of artistry, forensic science, anthropology, osteology, and anatomy.” This technique is used largely only when skeletal remains are the only evidence at the scene of a crime. Perhaps most famously, it was used in the facial reconstruction of Mitochondrial Eve—but just how accurate is forensic facial reconstruction?
The average person may believe that forensic facial reconstruction is successful and a good proxy for what an individual may have looked like. This is bolstered by the fact that people hear of stories in which facial reconstruction are successful, never hearing of the countless number of cases in which the “reconstruction” fails to identify anyone.
Numerous papers in the literature, though, do show that forensic facial reconstruction does have a high success rate. For instance, Lee et al (2011) and Wilkinson et al (2006) show that this method has a considerable chance of getting facial morphology in the ballpark of how they look. However, this was done on live subjects and is of no use for Mitochondrial Eve/deceased individuals. Facial reconstructions of the deceased are, for the purpose of this article, what we need to look at, not studies looking at live people. (There are also hurdles for facial recognition systems.)
One of the biggest hurdles for the accuracy of forensic facial reconstruction is that average facial tissue thickness cannot be inferred (most importantly, the lips, cartilage, skin and fat). Due to this, with no prior information to look at, the look of the skull will be subjective with the “reconstruction” looking somewhat similar due to chance. Further, the main facial features are largely determined by the shape of the skull.
Now to the fun part: Is this what Mitochondrial Eve really looked like?
There are a number of features that are problematic to infer from these facial reconstructions. Lips, ears, skin, craniofacial muscles—all are extremely hard, or next to impossible, to predict if the only thing we had was a skeleton. Further, since there are few tested relationships between soft and hard tissue for modern humans “it is clear that the use of facial approximation techniques on ancestral skulls of modern Homo are fundamentally flawed, as previously reported by Montagu” (Stephan, 2003). Since soft tissue quickly decays, it is left up to artistic interpretation. Further, attempting to map ape morphology since we diverged a few million years before is misleading, due to the fact that hard and soft tissue relationships are not likely to be the same for apes and our hominin ancestors.
Now that we know the so-called “reconstruction” of Mitochondrial Eve is not what she really looked like, there are a few more problems with this method I’d like to go over.
Forensic facial reconstruction is used when the remains of an unidentified individual are discovered. If the bones of the deceased are all that forensic artists have to go off of, the finished product may be extremely subjective/biased. People who believe that forensic facial reconstruction truly works may say “It works all the time. If it didn’t, how would it be able to solve crimes?” Success rates for the identification of individuals ranges from 50 to 100 percent (Stephan, 2003: 196), and so, the belief that “reconstructions” are largely accurate continue to persist.
However, like with the case of the famous stereotype threat with a modicum of unpublished studies, the “success” of forensic facial reconstruction is also skewed by non-reporting of unsuccessful cases
It is also rare for forensic facial approximation to be to be better than chance, with 403 incorrect facial identifications out of 592 identification scenarios in one study (Stephan and Henneberg, 2001). Facial reconstruction has the greatest accuracy if there is any knowledge of past injuries for the individual, a photo, and soft tissue. Obviously, in the case of Mitochondrial Eve, we don’t have a photo nor do we have soft tissue and knowledge of past injuries are a non-factor. So it seems that if some people claim to know what the first AMH looked like, it’s probably “just a guess”, and a pretty bad one at that due to the no knowledge of hard and soft facial tissue in the hominin lineage.
The hardest part about facial reconstruction is reconstructing soft tissues accurately since they quickly decompose. This is even more of a problem for people who lived hundreds of thousands of years ago. We’ve never seen any alive so we don’t know what they may have looked like to be able to infer what Mitochondrial Eve would have looked like. Things like lips/mouth, skin, hair, and ears are largely up to artistic interpretation, which are subjective in nature. Craniofacial morphology has also changed in the past 200 thousand years, which may be due to a decrease in testosterone/androgen receptors.
If we can’t identify humans with facial recognition better than chance, what makes anyone think that we can even have the slightest idea of how Mitochondrial Eve looked—when some of the most important parts of the phenotype aren’t around to observe and thus subjectivity then comes into play. Any “reconstructions” you come across, you should take with a grain of salt. It’s next to impossible to know what ancient hominins may have looked like due to the absence of soft tissue, and so any phenotype that a so-called “reconstruction” may give is, largely, up to the interpretation of the individual artist.
With our current technology, it’s next to impossible to ascertain what Mitochondrial Eve—or any other ancient hominin for that matter—may have looked like.
Lee, W., Wilkinson, C. M., & Hwang, H. (2011). An Accuracy Assessment of Forensic Computerized Facial Reconstruction Employing Cone-Beam Computed Tomography from Live Subjects. Journal of Forensic Sciences,57(2), 318-327. doi:10.1111/j.1556-4029.2011.01971.x
Stephan, C. (2003). Anthropological facial ‘reconstruction’ – recognizing the fallacies, ‘unembracing’ the errors, and realizing method limits. Science & Justice,43(4), 193-200. doi:10.1016/s1355-0306(03)71776-6
Stephan, C. N., & Henneberg, M. (2001). Building Faces from Dry Skulls: Are They Recognized Above Chance Rates? Journal of Forensic Sciences,46(3). doi:10.1520/jfs14993j
Wilkinson, C., Rynn, C., Peters, H., Taister, M., Kau, C. H., & Richmond, S. (2006). A Blind Accuracy Assessment of Computer-Modeled Forensic Facial Reconstruction Using Computed Tomography Data From Live Subjects. Forensic Science, Medicine and Pathology,2(3), 179-188. doi:10.1385/fsmp:2:3:179
Wilkinson, C. (2010). Facial reconstruction—anatomical art or artistic anatomy? Journal of Anatomy,216(2), 235-250. doi:10.1111/j.1469-7580.2009.01182.x
How many of you have read wrongthought books in public? Books like Race, Evolution, and Behavior, The Blank Slate, The Nurture Assumption, or any other kind of wrongthought literature? I’ve had two specific run-ins this week reading a wrongthought book in public, both people giving me the expected reaction “Why are you reading that?” I bring a few books with me in my daily travels, one of them being Taboo: Why Black Athletes Dominate Sports and Why We’re Afraid To Talk About It.
I was in the bookstore the other day reading Taboo while drinking some coffee and someone came up to me and said, “Why are you reading that?” I responded, “Because I’m interested in the material, why else why I read it?” The person scowled at me and walked away. I don’t understand why you need to ask dumb questions like that. Clearly, if I’m reading something I find an interest in it. People are clearly scared of acknowledging any kind of racial differences in public—even if they cheer for their favorite sports teams a few times a week, not realizing that they’re cheering on people who have inherent genetic advantages due to their morphology. Ironically enough, the book I was reading was talking about how and why blacks dominate sports. That’s ‘racist’ though, so people don’t want to talk about it specifically in public, but they know the truth unconsciously.
As I wrote the other day, people are scared of talking about things that are “natural” in human populations. Because the admission of one population being inherently better, on average than another would then open the gates to talking about other more uncomfortable things, such as racial differences in intelligence. I bet seeing someone read a book like Taboo in public without having knowledge of population differences is pretty jarring for someone who is not privy to the information. However, as we all know, reality isn’t based on how we wish it to be. These taboo subjects that people are scared to approach don’t go away if they don’t acknowledge them.
I had another run-in the other day while drinking some coffee, reading the same wrongthought book. The person asked me “Why are you reading that in public?” with a surprised look on his face. I laughed and said, “Because I can,” and sipped my coffee. People don’t want their preconceived notions challenged (the notion of ‘equality’ of human races). To see someone reading a wrongthought book in public is heresy, and people will always give you an odd look if you’re reading one in public.
I also saw someone reading Outliers by Malcolm Gladwell the other day and I just had to tell them that Gladwell is wrong in his contention that practicing something for 10,000 hours is something that Gladwell has been rebutted on and continues to perpetuate. People should always know there are two sides to every story, whether they want to hear it or not.
People change their minds through reading. So if people who’ve not been exposed to wrongthought books see others reading them, they may be compelled to look into it themselves. That’s the best part about reading those types of books in public. A person may look into it themselves and change their views. I’ve personally found it much easier to change my views on something when I’ve read it myself in comparison to if I’m debating someone.
There is a cognitive bias known as the ‘backfire effect’, where correcting someone actually increases their misperceptions. Engaging people’s beliefs, in the end, just makes them hold onto them more strongly and has them search for evidence to confirm their beliefs. So by people being exposed to wrongthought books they can see them and look into it for themselves and weigh both sides on their own without the possibility of the backfire effect.
So just by exposing others to the covers of these wrongthought books may have them look into something themselves and, possibly, someone else will accept genetic causes for human differences. If you do read a wrongthought book in public and someone attempts to engage you due to what you’re reading, remember the backfire effect. This is why debating people doesn’t change their views because showing people they are wrong (with scholarly sources) has them hold onto their views more strongly. To avoid this, just read a wrongthought book in public so people can see it and look into it themselves.