I was somewhat surprised that this article at Science Now on the effects that the development of agriculture had on the European genome highlights skin and eye color:
One surprise is that the La Braña man had dark skin and blue eyes, a combination rarely seen in modern Europeans. Although today’s southern Europeans tend to be somewhat darker than their northern counterparts, they are still relatively light-skinned compared with Africans, an adaptation often linked to the need to absorb more sunlight and so produce adequate amounts of vitamin D. That this feature of the La Braña skeleton might have been widely shared and not just a one-off is also suggested by recent findings, as yet unpublished but posted online in preliminary form, that other European hunter-gatherers also had dark skin and blue eyes.
rather than what is to me the most obvious development: the ability to digest milk, i.e. break down lactose. It is mentioned in passing
This is something I did not know:
But the La Braña man did have some talents thought to have originated only with farming societies: His immune system was apparently capable of fighting off a number of diseases, such as tuberculosis, pneumonia, and malaria (which was endemic in southern Europe until modern times), which researchers had assumed were passed to humans from animals once cattle, sheep, and other species were domesticated. Out of 40 genes involved in immunity that the team looked at, 24 (60%) were similar to those of modern Europeans. “It appears that the first line of defense against pathogens was already there,” says Wolfgang Haak, an ancient DNA researcher at the University of Adelaide in Australia. One possible explanation, Lalueza-Fox adds, is that “epidemics affecting early farmers in the [Middle East] spread to continental Europe before they went themselves.”
which would seem to support Jared Diamond’s hypothesis.