Cleaning off my desk this evening, I found an interesting paper I’d printed and set aside to read weeks ago by Alison Smith in Holocene about the relationship between climate change and human evolution. Smith uses data from the human genome project on the timing of major bits of human evolution to argue that pressures from abrupt climate change during the last 10,000 years can be linked in time to major steps in human evolution:
For example, 5000 to 6000 years ago, changes occurred in the human genome, including among others
the development in some populations of lactose tolerance, the development of malarial resistance and an increase in brain size. These changes occurred in regionally distributed populations responding to some strong positive selection pressure. I suggest that the source of the selection pressure may have been the abrupt climate change documented as occurring at the close of the mid-Holocene hypsithermal climatic optimum), 5000–6000 years ago.
Many years ago, selection pressure was enforced, probably, because the affected humans could not move away from the changing climate. This time many humans could move and so the selection pressure, if there is any, should be much different.
Oh, I think there will be selection pressure all right in a materials-limited world. Look at how competive Murrican parents are becoming in getting their children’s resumes started at 7 years old. Societies evolve too, and societal evolution occurs at scales we can comprehend and measure, unlike episodic mutations (well, for now anyways and this paper appears to be getting closer).
Best,
D
John:
William Calvin at UW in Seattle has been writing on the topic of climate bottlenecks and the evolution of modern man for some time.
http://williamcalvin.com/1990s/1999intelligence-chapter.htm
Here’s a better link: http://williamcalvin.com/2004/FFF.htm
i disagree. humans have been controling thair enviroment since way before Neolithic times, since then, humans have not changed much, because we do not have the “survival of the fittest” elements. as if we cant out-run a tiger, a human pickes up a spear and turns it into a meal. the evolution of man as far as inteligence goes is the only element which i consider to still be in eveloution, if, however civalisation were to collapse, evolution would show it’s mark on humanity once more. As i say, social and Technological evolution are still in operation, yet physical evolution does happen in isolation, say, Differing race, eventually, the gene pool will merge and produce humans very alike, this could be dangerous, as with a limited gene pool, new threats could rise and the human race destroyed by a simple sickness, such as HIV/AIDs, which i now believe some people have an immunity to. so big WOOP for human aduptartion and survival!