Monday, October 06, 2008
Leading geneticist Steve Jones says human evolution is over. Steve Jones has an appointment in the Galton laboratory, and has written several books on human genetics (e.g., Y: The Descent of Man and Darwin's Ghost: The Origin of Species Updated). But he says things like this:
"Small populations which are isolated can evolve at random as genes are accidentally lost. World-wide, all populations are becoming connected and the opportunity for random change is dwindling. History is made in bed, but nowadays the beds are getting closer together. We are mixing into a glo-bal mass, and the future is brown."
First, we're nowhere close to panmixia.* Second, there is going to be a large variance around the expectation. Even if you remove new mutations, there are a lot of variants out there for selection to pick up from the extant genetic background I would think. The future will not be brown for the same reason that people in an English village do not all have the same hair color despite there being a lot of intermarriage.
Lots of other things to point to that leave you confused in that piece, but I'll leave it as an exercise for the readers....
* And what about the lack of importance of population size as a parameter effecting substitutions in Neutral Theory? I know there are ways you can object to this, but Jones' quote seems to garble many issues here.
Update: I emailed an academic who I suspected would know if Jones was being quoted out of context or misrepresented. But they say that this is probably an accurate representation of his views (and they also seem to think that his coherency leaves a bit to be desired).
Update II: Here is Chris Stringer's rebuttal to Jones:
But Professor Chris Stringer, research leader in human origins at the Natural History Museum, London, said the idea that evolutionary pressures were no longer taking their toll on humanity was true of only western civilisation.
*roll eyes* Someone should tell these guys that you don't need to die to not reproduce.