I’ve read through the evolution issue of Scientific American, and the latest article I wanted to write about was titled, “If I Had a Hammer.” Here, the author, Ian Tattersall, a paleoanthropologist at the American Museum of Natural History in New York City, considers what makes us different from the ape-like creatures he believes we evolved from, and how we got to where we are. He accepts that those apelike creatures once had cognitive abilities similar to that of chimpanzees, but neither of these ape species had the ability to use symbols to create new realities like modern humans- who are the only beings capable of transforming their surroundings and experiences into vocabulary, envision a future, and make it a reality.
Tattersall believes that, in order for our species (Homo sapiens) to reach our present level of cognition from our apelike ancestors, it “took a lot of fast evolutionary modification.” I find this interesting because evolution is often thought of as a slow, gradual process, and it’s even defined as a slow change that happens over a very long time. Yet such a scenario would be insufficient to cross the chasm from them to us. Tattersall reiterates that, even though we’re talking about seven million years in the past, the type of transition necessary had to be quick. To illustrate, he asks us to compare the cognitive abilities of modern primates; there’s not much difference between how a chimpanzee, orangutan, or gorilla thinks. But when we throw humans into the mix, we can see an incredible, radical gap! How did we surpass them by such an incredible margin?
I find it odd that the author is able to identify such a disparaging difference, yet he has no problem contributing this to evolution, rather than a creator. I think the existence of God is actually a more logical conclusion and better explains this huge contrast.
This leaves Tattersall with the problematic task of determining how humans could have evolved so rapidly, and what mechanisms caused this acceleration. He concludes that the answer must have been our ancestor’s ability to make tools, clothing, shelter, fire and such; the more capable and innovative individuals would out-survive those who were not. Unfortunately, this isn’t a very satisfying answer. Suggesting that evolution “did it” doesn’t explain how evolution did it. He simply assumes evolution was occurring, and other influences made it happen really, really fast.
What I want to know is how these imaginary ancestors evolved the ability to create tools and fire in the first place and what triggered larger brains. It seems obvious that the most innovative would be better equipped to survive, but such truth doesn’t help chimps erect huts, carve arrowheads or cook their food. If it were that simple, gorillas would be able to develop their own alphabet and teach math. So, why don’t orangutans have the ability to meet the challenges they face by producing stone tools? Why doesn’t natural selection favor those apes best able to innovate and share their cultural know-how today? These are important questions that Tattersall doesn’t answer.
Instead, Tattersall goes on to consider the role of climate shifts in quickening the evolutionary pace. He believes that rapid evolution simply happened when populations “splintered,” allowing different traits to appear faster than it otherwise would have in larger groups. He explains that smaller populations are ideal for allowing rapid changes to occur because it allows for the fixation of certain traits, and I concur. Large populations, on the other hand, don’t allow for much inertia (perhaps that’s why we don’t see humans evolving into something else today). Nonetheless, it’s simply his worldview that compels him to believe that we were evolving to begin with, and that evolution- if it were even possible- could occur at such blinding speeds and be so transformative. Further, there still remain isolated tribes in South America that have never been in contact with the outside world, and when we do initiate first contact, we see no evidence of evolution among them. So these explanations fail to explain how ape-like creatures evolved the ability to manipulate their environment and create tools. He just assumes it happened, and because it happened while the climate was dramatically changing, we benefited. Very fortunate for us, huh?
It’s also not uncommon to find scientists today who believe that dramatic climate change is happening, yet we don’t see chimps picking up stones and shaping them into axes in order to build houses; so why isn’t this rapid change happening today?
Conveniently, Tattersall ignores all this and assumes these apelike creatures were in the process of evolving more humanlike traits as the climate changed; these new cognitive abilities allowed them to carve stone tools- something modern apes can’t do. Therefore, the first beings capable of making stone tools raced beyond the cognitive abilities of their brothers, leaving them forever behind in the dust.
Tattersall believes that the diet of these tool-makers changed as well, and that an enriched diet propelled a rapid expansion of our brain, which was another benefit to survival. He recognizes that this rate of “brain gain” was amazing, and he seems to resort to chance as the mechanism; humans were just lucky that their brain was expanding, that their diet was changing, and that they evolved the ability to make tools and such as the climate was changing, giving them the survival advantage they needed.
Tattersall does offer one explanation for rapid brain development called gene-culture coevolution; but this explanation also assumes that the brain was evolving and expanding (not how it happened), and once that happened, natural selection took over, providing powerful feedback within the culture, which promoted bigger brains and smarter individuals. With this model, our ancestors were “obliged” to become more intelligent, predisposing us to faster evolutionary change during periods of rapid climate shifts. Too bad other apes weren’t fortunate enough to experience this phenomenon.
At least Tattersall notices some of the assumptions demanded by this model, and he concedes that the evolved traits were unrelated to climate change. In other words, if these apelike creatures weren’t in the process of evolving humanlike traits in the first place, then the climate and other factors would have had no effect, and we might have become just another extinct ape…
In summary, evolution was occurring, transforming us into bipedal hominins with larger skulls and brains; this newfound intelligence gave us the ability to make tools and utilize them. Then natural selection and a rapidly changing climate kicked in, splintering various populations of apes, and spurring us toward exceptionally fast evolution.
It’s not surprising that Tattersall concludes that humans are an evolutionary accident. Interestingly, he ends with a dose of morality, saying that we have free will and can choose how we behave, and we must accept responsibility for those choices.
My main criticism is that this model doesn’t consider if evolution is even possible- it just assumes it and demands it, despite the absurdity. In contrast, believing that God created us fully human is a much more reasonable explanation. I think it’s easier to believe that we were created intentionally by a loving God with the intelligence necessary to manipulate our environment. The reason why there’s such a tremendous gap between us and apes (and all other animals, for that matter) is because we’re not related to them- not because we just happened to evolve really fast.