Excavating at Olduvai to find whether climate changes 2 million years ago may have contributed to human evolution

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Permalink Reply by Scott Bidstrup on October 18, 2010 at 4:19pm

Recent studies have suggested that humankind is still rapidly evolving; the presumption that because we are not under environmental stress (at the moment) does not mean we are not under selective pressure.

Indeed, who among us would not prefer to marry (and parent our children by) a mate that we find highly attractive and intelligent? As long as those preferences are predominant or at least very common in mate selection, and the traits being preferred are at least in part genetically determined, there is selective pressure in the human species selecting for those traits - evolution towards their more common expression.

Given enough generations, we as a species are going to change as a result of this selective pressure. Those traits being selected against may still exist in the genome, but will become less predominant until they finally die out and the genes coding for them become extinct. At that point, it can be truly said that we have evolved - even in the absence of environmental stressors.

Remember that even Darwin bristled at the use of the phrase "survival of the fittest." He never said any such thing (the phrase was invented by a journalist), but what he said, over and over, was survival of the most reproductively successful. The peacock being the obvious example of the latter being more accurate a description of evolution than the former. Genghis Khan allegedly had over a thousand children by the hundreds of women in his harem - and now something like 16% of the Mongolian population can trace ancestry to him. Was he that much more fit than the rest of the Mongols of his time? I don't think so. He was just more reproductively successful.

Scott B.

Permalink Reply by Jim DePaulo on October 18, 2010 at 5:33pm

Evolution, in its simplest definition, is the change over time. in the frequency of a gene, or genes, within a population's gene pool. By that definition we are constantly evolving even if we can't see it in the phenotype.

Permalink Reply by kiki on October 19, 2010 at 5:42pm

I would think @Gavin Sullivan.. "that our technical develoment has allowed us to partially reduse those selective pressures on our evolution" I would agree with that statement in that without the technical development our evolution would probably elvolving in a completly different direction..would there be less people, more people? I often wonder having the information concerning nature developments have we lost the ability to adapt as well as our ancestors did in the past? I dont know as much about this as I would like to so any comments to this are appreciated.