The concept of the EEA, the Environment of Evolutionary Adaptedness, never made much sense. In its strong form it is based on the misunderstanding that we evolved during the Stone Age, and then we more or less stopped evolving.
World Science reports on a study by Greg Cochran and John Hawks,
The traditional picture of humans as a finished product began to erode in recent years, scientists said, with a crop of studies suggesting our evolution indeed goes on. But the newest investigation goes further. It claims the process has actually accelerated.
It also downplays the importance of a much-scrutinized era around 200,000 years ago, when humans considered “anatomically modern” first appear in the fossil record. In the study, this epoch emerges as just part of a vast arc of accelerating change.
“The origin of modern humans was a minor event compared to more recent evolutionary changes,” wrote the authors of the research, in a presentation slated for Friday in Philadelphia at the annual meeting of the American Association of Physical Anthropologists. [...]
Hawks and Cochran said some of the most notable physical changes in humans have been ones affecting the size of the brain case.
A “thing that should probably worry people is that brains have been getting smaller for 20,000 to 30,000 years,” said Cochran. But brain size and intelligence aren’t tightly linked, he added. Also, growth in more advanced brain areas might have made up for the shrinkage, Cochran said; he speculated that an almost breakneck evolution of higher foreheads in some peoples may reflect this. A study in the Jan. 14 British Dental Journal found such a trend visible in England in just the past millennium, he noted, a mere eyeblink in evolutionary time.
Research published in the Sept. 9, 2005 issue of the research journal Science by Lahn and colleagues found that two genes linked to brain size are rapidly evolving in humans.