Darwin and Human Evolution: A Two-Day Symposium at Dartmouth College

Contributed by E. A. Meigs

Dartmouth College hosted a two-day symposium, Darwin and Human Evolution Symposium, on February 17-18, 2023, “Reflecting on Charles Darwin’s impact on the study of human evolution and biological diversity a century and a half after he published Descent of Man”. This event featured authors who contributed to A Most Interesting Problem: What Darwin’s Descent Got Right and Wrong about Human Evolution (Princeton University Press, 2021). Unfortunately, I was able to attend only the first day of the symposium; nevertheless, I found it was well worth the trip from out-of-state!

We were welcomed by Dr. Jeremy DeSilva (Dartmouth College), who spoke of honoring the 152^nd anniversary of Charles Darwin’s publication, Descent of Man. Dr. DeSilva then raised questions regarding Darwin’s work: specifically, whether the origin of humans is knowable, how Darwin attempted to understand the processes of human evolution, and the notion that Darwin did not wish to present his work as infallible, but as hypotheses to be explored.

Dr. Suzana Herculano-Houzel (Vanderbilt University) opened with Remarkable but not extraordinary: The evolution of the human brain.

Dr. Herculano-Houzel delved into “Human evolution fulfills a need”. We humans have acquired biological capacity beyond what body requires. This additional capacity, gained by a self-reinforcing pattern of ability to modify our surroundings to invent and implement technology and create culture, and to develop complexity, self-organization, flexible behaviors – considering not only the present, but also the past and the future. As technology gave rise to more (and better quality) foods, humans grew larger brains (with more neurons) and bigger bodies, which allowed them to stay awake longer, to develop more technology, eat more food, learn more, continue to grow bigger brains and bodies, while simultaneously giving rise to longer childhoods and longer nurturing periods for children, including longer periods of cultural and technological transmission, again adding to the self-reinforcing pattern.

Dr. Jeremy DeSilva (Dartmouth College) returned to discuss Darwin’s thoughts on human evolution and how the paucity of relevant data and fossils available to Darwin may have affected his work.

Darwin noted the ways in which humans were different from other hominids in that we are bipedal, have larger brains, smaller canine teeth, and a greater reliance on technology. Darwin hypothesized that free use of arms and hands to wield tools and develop technology meant less need for fangs. Darwin correctly predicted that hominid fossils would be found in Africa, while others thought hominid fossils would only be found in Europe or Asia. Thousands of hominid fossils have been found since Darwin’s time, but we are still pondering: from whom did we evolve? Which body-type did our ancient ancestors have? Darwin pondered this as well, but he didn’t think we could make assumptions or draw definite conclusions at that time. Additionally, Darwin questioned when did hominins begin to walk upright and why was it that humans were bipedal and other hominids were not? Was it possible that none of our ancient ancestors were knuckle walkers?

Dr. Brian Hare (Duke University) followed by covering Chapter 3 The Evolution of Morality: The Darwinian road to morality.

Darwin got a lot right: he made comparisons of mental powers of man and lower animals, and survival of the fittest versus survival of the friendliest. Dr. Hare also spoke of mankind’s advantageous traits: sympathy, and the idea that cooperation; a “purposeless evolution mechanism” is actually purposeful, after all.  Humans share varying degrees of these components: communication, sympathy, empathy, reasoning, memory, self-command, cunning, regret, and love, which Dr. Hare compared with apes, who exhibit some of the same behaviors.

John Hawks (University of Wisconsin) ended the afternoon’s program by taking on Chapter 6: Ranking humanity among the primates. Dr. Hawks guided us through Darwin’s writings: his book Descent of Man and some of his personal notes.  He observed that Darwin wrote a number of problematic things, but he was correct in many instances, especially in his ideas connected to evolutionary trees, particularly in regards to human evolution, as opposed to the well-known “March of Progress” graphics.   

Darwin, like many other scientists, contemplated the idea that mankind is unique among all other species inhabiting our planet. Primates have been around for more than 60 million years, and many of their niches have gone extinct.  Today’s Homo sapiens are the only survivors of our lineage. Darwin argues, however, that we are not special. Dr. Hawks quoted:

 Thus we have given to man a pedigree of prodigious length, but not, it may be said, of noble quality. The world, it has often been remarked, appears as if it had long been preparing for the advent of man; and this, in one sense is strictly true, for he owes his birth to a long line of progenitors. If any single link in this chain had never existed, man would not have been exactly what he now is. Unless we wilfully close our eyes, we may, with our present knowledge, approximately recognise our parentage; nor need we feel ashamed of it. The most humble organism is something much higher than the inorganic dust under our feet; and no one with an unbiassed mind can study any living creature, however humble, without being struck with enthusiasm at its marvellous structure and properties. (The Descent of Man, and Selection in Relation to Sex, Charles Darwin, 1871)

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I would like to thank Dartmouth College for allowing me to be a guest attendee at their symposium. I am also so very grateful to Dr. Hawks and Dr. Fuentes for kindly taking the time to chat with me.

This article is based on my notes from the day’s talks. I apologize if I have misinterpreted of the speakers’ presentations.