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.
The soft spot on a baby’s head may be able to tell us when our ancestors first began to speak.
Evolution works on different scales. In a single day, HIV’s genetic code changes as it adapts to our ever-adapting immune system. Over the course of decades, the virus can make a successful leap from one species to another (from chimpanzees to humans, for example). Over a few thousand years, humans have adapted to agriculture–an adult tolerance to the lactose in milk, for example. Over a couple million years, the brains of our hominid ancestors have nearly doubled. Sometimes scientists distinguish between these scales by calling small-scale change microevolution and large-scale change macroevolution. Creationists have seized on these terms and used them to build one of their central canards: that they accept microevolution but can then reject macroevolution. That’s a bit like accepting microeconomics–how households and firms make decisions and interact in markets–but then denying macroeconomics–how entire societies produce goods, how inflation rises and falls, and so on. Evolutionary biologists debate fiercely about how macroevolutionary change emerges from microevolution. But they continue to find abundant evidence that the two are a package deal.