1600 words

Wind back the tape of life to the origin of modern multicellular animals in the Cambrian explosion, let the tape play again from this identical starting point, and the replay will populate the earth (and generate a right tail of life) with a radically different set of creatures. The chance that this alternative set will contain anything remotely like a human being must be effectively nil, while the probability of any kind of creature endowed with self‐consciousness must also be extremely small. (Gould, 1996. Full House)

Wind back the tape of life to the early days of the Burgess Shale; let it play again from an identical starting point, and the chance becomes vanishingly small that anything like human intelligence would grace the replay. (Gould, 1987. Wonderful Life)

Wind back the clock to Cambrian times, half a billion years ago, when mammals first exploded into the fossil record, and let it play forwards again. Would that parallel be similar to our own? Perhaps the hills would be crawling with giant terrestrial octopuses. (Lane, 2015: 21. The Vital Question)

I first read Full House (Gould, 1996) about two years ago. I never was one to believe in evolutionary “progress”, though. As I read through the book, seeing how Gould weaved his love for baseball into an argument against evolutionary “progress” enthralled me. I love baseball, I love evolution, so this was the perfect book for me (indeed, one of my favorite books I have read in my life—and I have read a lot of them). The basic argument goes like this: There are more bacteria on earth than other animals deemed more “advanced”; if evolutionary “progress”—as popularly believed— were true, then there would be more “advanced” mammals than bacteria; there are more bacteria (“simpler: animals) than mammals (more “advanced” animals); therefore evolutionary “progress” is an illusion.

Evolutionary “progress” is entrenched in our society, as can be seen from popular accounts of human evolution (see picture below):

This is the type of “progress” that permeates the minds of the public at large.

Some may look at the diversity of life and conclude that there is a type of “progress” to evolution. However, Gould dispatches with this type of assertion with his drunkard argument. Imagine a drunkard leaving the bar. There is the bar wall (the left wall of complexity) and the gutter (the right wall of complexity). As the drunkard walks, he may stumble in between the left wall and the gutter, but he will always end up in the gutter every time.

Gould explains then explains his reasoning for using this type of argument:

I bring up this old example to illustrate but one salient point: In a system of linear motion structurally constrained by a wall at one end, random movement, with no preferred directionality whatever, will inevitably propel the average position away from a starting point at the wall. The drunkard falls into the gutter every time, but his motion includes no trend whatever toward this form of perdition. Similarly, some average or extreme measure of life might move in a particular direction even if no evolutionary advantage, and no inherent trend, favor that pathway (Gould, 1996: 151).

The claim that there is a type of “progress” to evolution is only due to the fact—in my opinion—that humans exist and are the most “advanced” species on earth.

It seems that JP Rushton did not read this critique of evolutionary “progress”, since not even a year after Gould published Full House, Rushton published anew edition of Race, Evolution, and Behavior (Rushton, 1997) where Rushton argues (on pages 292-294) that there is, indeed, “progress” to evolution. He cites Aristotle, Darwin (1859), Wilson (1975) Russell (1983, 1989; read my critique of Russel’s theory), and Bonner.

To be brief:

The Great Chain of Being (which Rushton’s r/K selection theory attempts to revive) is not valid; Wilson’s idea of “biological progression” is taken care of by Gould’s drunkard argument; Bonner asks why there has been evolution from simple to advanced, and this, too, is taken care of by Gould’s drunkard argument, and finally Dale Russel’s argument about the troodon (I will expand on this below).

Rushton claims that Russell, in his 1989 book Odysseys in Time: Dinosaurs of North America (which I bought specifically to get more info on Russel’s thoughts on the matter and to get more information for an article on it) that “if [dinosaurs] had not gone extinct, dinosaurs would have progressed to a large-brained, bipedal descendent” (Rushton, 1997: 294). Either Rushton only glanced at Russel’s writings or he’s being inherently dishonest: Russel claimed that had the dinosaurs not gone extinct, one dinosaur—the troodon—would have evolved into a bipedal, human-like being. Russel made these claims since the troodon had EQs about 6 times the size of the average dinosaur and they ran on two legs and had use of their ‘hands.’ So, due to this, Russel argues that had the dinosaurs not gone extinct, the troodons could possibly have been human-like. However, there are two huge problems for this hypothesis.

In the book Up From Dragons, Skoyles and Sagan (2002: 12) write:

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.

So, since dinosaurs are cold-blooded and being tied to the sun restricts their behavior, if they would have survived the K-T extinction event, then it is highly implausible that they would have grown brains our size.

Furthermore, Hopson (1977: 444) 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.

Gould even writes in Wonderful Life:

If mammals had arisen late and helped to drive dinosaurs to their doom, then we could legitimately propose a scenario of expected progress. But dinosaurs remained dominant and probably became extinct only as a quirky result of the most unpredictable of all events—a mass dying triggered by extraterrestrial impact. If dinosaurs had not died in this event, they would probably still dominate the large-bodied vertebrates, as they had for so long with such conspicuous success, and mammals would still be small creatures in the interstices of their world. This situation prevailed for one hundred million years, why not sixty million more? Since dinosaurs were not moving towards markedly larger brains, and since such a prospect may lay outside the capability of reptilian design (Jerison, 1973; Hopson, 1977), we must assume that consciousness would not have evolved on our planet if a cosmic catastrophe had not claimed the dinosaurs as victims. In an entirely literal sense, we owe our existence, as large reasoning mammals, to our lucky stars. (Gould, 1989: 318)

I really don’t think it’s possible that brains our size would have evolved had the dinosaurs not gone extinct, and the data we have about dinosaurs strongly points to that assertion.

Staying on the topic of progression and brain size, there is one more thing I want to note. Deacon (1990a) argues that fallacies exist in the assertion that brain size progressed throughout evolutionary history. One of Deacon’s fallacies is the “evolutionary progression fallacy.” The concept of “progress” finds refuge “implicit expression in the analysis of brain-size differences and presumed grade shifts in allometric brain/body size trends, in theories of comparative intelligence, in claims about the relative proportions of presumed advanced vs. primitive brain areas, in estimates of neural complexity, including the multiplication and differentiation of brain areas, and in the assessment of other species with respect to humans, as the presumed most advanced exemplar” (Deacon, 1990a: 195).

This, in my opinion, is the last refuge for progressionists: looking at the apparent rise of brain size in evolutionary history and saying “Aha! There it is—progress!” So, the so-called progress in brain size evolution is only due to allometric processes, there is no true “progress” in brain size, no unbiased allometric baseline exists, therefore these types of claims from progressionists fail. Lastly, Deacon (1990b) argues that so-called brain size progress vanishes when functional specialization is taken into account.

Therefore it is unlikely that dinosaurs would have evolved brains our size.

In sum, there are many ways that progressionists attempt to show that there is “progress” in evolution. However, they all fail since Gould’s argument is always waiting to rear its head. Yes, some organisms have evolved greater complexity—i.e., moved toward the right wall—though this is not evidence for “progress.” Many—if not all—accounts of “progress” fail. There is no “progress” in brain size evolution; there would not be human-like dinosaurs had the dinosaurs not gone extinct in the K-T extinction event. We live on a planet of bacteria, and since we live on a planet of bacteria—that is, since bacteria are the most numerous type of organism on earth, evolutionary progress cannot be true.

Complexity—getting to the right wall—is an inevitability, just as it is an inevitability that the drunkard would eventually stumble to the gutter. But this does not mean that there is “progress” to evolution.

The argument in Gould’s Full House can be simply stated like this:

P1 The claim that evolutionary “progress” is real and not illusory can only be justified iff organisms deemed more “advanced” outnumber “lesser” organisms.
P2 There are more “lesser” organisms (bacteria/insects) on earth than “advanced” organisms (mammals/species of mammals).
C Therefore evolutionary “progress” is illusory.