In the conclusion to “Endless Forms Most Beautiful”, Sean “not the astrophysicist” Carroll writes “The evolution of form is the main drama of life’s story”, suggesting we move away from teaching evolution defined as change in gene frequencies. In the previous chapter he notes “most proteins in the body do not affect form – they carry out other roles in physiology. There may be some interesting differences in proteins involved in physiology, such as the sense of smell, immunity, or reproduction, but these do not affect the way mice or humans appear”. Why is the “main drama” about appearance? I understand that there’s little else available in the case of fossils, but it seems to me those other aspects of physiology are quite important. They could well take up most of the evolution (which I’ll define here as non-neutral changes in DNA, whether coding or regulatory) throughout history. Let’s focus on just immunity. The “Red Queen Theory” suggests that we have to keep “running as fast as we can” just so as to not lose ground against simultaneously evolving parasites. For humanity, the neolothic revolution of agriculture, high population densities and travel has meant very intense selection for disease resistance. We can see the dramatic result of different immunological profile in the fate of north american indians (the different fate of Africa & South America is due to the local advantage against tropical diseases). Yes, there has also been strong selection for lighter skin among Europeans & Orientals, but does that make for a more central drama than the aforementioned immune system adaptations or lactose digestion? Carroll puts a lot of attention on the mimicry of butterflies, but the only reason it is advantageous for one butterfly to resemble another is the poison that makes them unpalatable to birds. On second thought, that might also involve a change in “form”, I’m not sure. In case Carroll or someone else knowledgeable reads this, please clarify.
On a sidenote, it’s funny that he writes “Biology without evolution is like physics without gravity”, because theoretical physicists have had such a hard time integrating gravity into a unified theory that already explains the the other forces on the quantum level.