In March, I wrote a post on some tantalizing new findings about the secrets of human evolution lurking in our genome. In brief, researchers at the University of Pennsylvania studied a gene called MYH16 that helps build jaw muscles in primates. In our own lineage, the gene has mutated and is no longer active in jaw muscles. Perhaps not coincidentally, we have much smaller, weaker jaws than other apes. The researchers estimated that the gene shut down around 2.4 million years ago–right around the time when hominid brains began to expand. They suggested that shrinking jaw muscles opened up room in the hominid head for a larger brain.
Contempt is never wise in biology. The creature that you look down on as lowly, degenerate, or disgusting may actually turn out to be sophisticated, successful, and–in some cases–waiting to tell you a lot about yourself. That’s certainly the case for lice.
Congratulations to Linda Buck and Richard Axel for winning the Nobel Prize for Medicine today. They won for their pioneering work on the 600 or so receptors that we use to smell. As is so often the case these days, the research that wins people the Nobel for Medicine also reveals a lot about our evolution. This February, for example, Buck published a paper in the Proceedings of the National Academy of Sciences, in which she and her colleagues charted the evolutionary history of human olfactory receptors.
Every now and then you come across a scientific hypothesis that is so elegant and powerful in its ability to explain that it just feels right. Yet that doesn’t automatically make it right. Even when an elegant hypothesis gets support from experiments, it’s not time to declare victory. This is especially true in biology, where causes and effects are all gloriously tangled up with one another. It can take a long time to undo the tangle, and hacking away at it, Gordian-style, won’t help get to the answer any faster.
I am sure that in 50 years, we are going to know a lot more about how the mind works. The fusion of psychology and genetics will tell us about how our personality is influenced by our genes, and they’ll also show exactly how the environment plays a hand as well. The preliminary evidence is just too impressive to seriously doubt it. Likewise, I am sure that we will have a deeper understanding how our minds have evolved, pinpointing the changes in DNA over the past six million years have given us brains that work very differently than apes. Again, the first results can’t help but inspire a lot of hope.