Although I’m not finished with it quite yet, I feel compelled to write a few words about Craig Stanford’s book Upright: The Evolutionary Key to Becoming Human. The book started off being enjoyable and it certainly isn’t a bad read, but as I peeled through the pages a few things began to irk me about Stanford’s book.
While Stanford certainly does a good job explaining that the study of human evolution does not begin with Lucy and proceed in a straight line ending with you and I, I do feel there is a bit of bias towards Australopithecus as the milestone at which to begin discussions of evolution. Until I started doing some reading in my own time, I hadn’t even heard of Proconsul or earlier apes, the impression I got from science was that Lucy and her kind were certainly the beginning of our own family tree. Stanford should get credit for explaining early on that there was a greater diversity and abundance of apes prior to the Australopithecenes, but Lucy does get most of the attention. It would be unfair to have Stanford shoulder all of the blame, however, being that Lucy is certainly an important find and she has received far more attention (in both the scientific community and the public) than other primates. Still, I think reading audiences are shortchanged when the origin of primates is not discussed in these books, the change from tree shrew to primate being far more interesting (at least to me) than changes that occurred once the group had emerged. I feel this possibly fuels the bias that we “evolved from monkeys” or that chimpanzees are our last common ancestor still living today (rather than being derived from that ancestor).
Keeping the evolution and diversity of primates in mind, something else bothers me about the book; ecology takes a back seat to discussion of the fossils themselves. I’ve said this time and time again, but we can’t possibly understand evolution without understanding ecology, and if we are to understand how humans evolved we need to recognize the setting in which the changes were occurring. Some things will never be able to be ascertained, but by keeping ecology out of the picture I feel it creates the false impression that creatures evolve because that is simply what they’re meant to do. To his credit, Stanford does mention that the hypothesis that the whole of human evolution occurred on a Serengeti-like savanna is silly and briefly mentions the other times of habitats important primates lived in, but there is not nearly enough detail to accurately convey the interplay between the primates and their environment.
What I also find puzzling is that the title suggests that bipedalism was the key to human evolution, and yet Stanford spends an entire chapter explaining that bipedalism is not unique to humans alone. While his brief discussion of dinosaurs is weak, he does make the important point that bipedalism shows up at various times in the fossil record, even among some apes that did not lead to later hominids. Perhaps Stanford will clarify this later in the book by saying that our particular kind of bipedal gait was more efficient than earlier attempts by primates, so I will try to reserve judgment until I’m finished with the book.
This reminds me of my own hypothesis that binocular vision and shortening of the face may have helped contribute to intelligence, being that as a “face” develops in a species lineage, more visual communication opportunities show up. Emotions, for one thing, are able to be expressed with greater range and complexity, and understanding what another member of your kind means when it furrows its brow or smiles wide is important to survival in a social group. Sound, smell, and posture are all still important, of course, but I can’t help but wonder if the development of a flattened face that can be manipulated in more ways contributed to the increase in intelligence from tree shrew to primate. I have no evidence for this other than my own thought processes for the moment, but hopefully I’ll find something more tangible that verifies or refutes my ideas.