Human Evolution still in progress?

[Michael]

Here's an interesting development.

For decades the consensus view—among the public as well as the world’s preeminent biologists—has been that human evolution is over. Since modern Homo sapiens emerged 50,000 years ago, “natural selection has almost become irrelevant” to us, the influential Harvard paleontologist Stephen Jay Gould proclaimed. “There have been no biological changes. Everything we’ve called culture and civilization we’ve built with the same body and brain.” This view has become so entrenched that it is practically doctrine. Even the founders of evolutionary psychology, Leda Cosmides and John Tooby, signed on to the notion that our brains were mostly sculpted during the long period when we were hunter-gatherers and have changed little since. “Our modern skulls house a Stone Age mind,” they wrote in a background piece on the Center for Evolutionary Psychology at the University of California at Santa Barbara.

So to suggest that humans have undergone an evolutionary makeover from Stone Age times to the present is nothing short of blasphemous. Yet a team of researchers has done just that. They find an abundance of recent adaptive mutations etched in the human genome; even more shocking, these mutations seem to be piling up faster and ever faster, like an avalanche. Over the past 10,000 years, their data show, human evolution has occurred a hundred times more quickly than in any other period in our species’ history.
Source (http://discovermagazine.com/2009/mar/09-they-dont-make-homo-sapiens-like-they-used-to)

This is very interesting and suggests that humans (and human culture) is much more adaptive in short time frames than scientists have previously given credit to.

Any thoughts on this?

[Dominick]

That thesis seems perfectly logical to me. Evolution is nothing more than a reaction to changing circumstances and when those change more rapidly, evolution is bound to increase too. It's that or extinction. The whole thing is really that simple.

I suppose the claim that 'evolution had stopped' stems from politico-religious backgrounds. Such a statement requires a belief in exceptionalism for humans and/or a belief that 'progress', specifically technological progress, has some exceptionalist characteristic that would make humans immune to evolution. But it's that very technological progress that has increased the rate of change of environmental factors, and thus of any corresponding evolution,

That doesn't mean to say that current evolution would be catastrophic or revolutionary in nature. It would be as gradual as ever. Nothing carnivalesque is to happen to humans in the near future.

[dilettante]

I doubt there's a "politico-religious background" to claims that human evolution has slowed/stopped so much as there is an assumption that humanities' ability to rapidly evolve culturally has more or less rendered its much (MUCH) slower biological evolution obsolete.

That said, one might suggest that a multitude of changes in human genes over the relatively recent millennia is not necessarily evidence of evolution but possibly evidence of the decline of natural (biological) selection.

For example: Whereas in the past environmental changes might have given a particular biological subset of the species enough of an advantage to out-perform, out-reproduce, and eventually out-survive other subsets, cultural adaptation allows those subsets to make up for their biological deficiencies (to some extent) by changing their survival practices and techniques. Consequentially, they survive as well and their genetic diversity is not eliminated from the species. I.E. Survival of the (biological) fittest becomes survival of the (biological & cultural) fit, a potentially larger and more diverse group.

Given enough data, one could theoretically test for such a process by looking for cases in which genetic traits entered the species (or remained in the species) even though they were disadvantageous because the bearers of those traits had devised cultural adaptations sufficient to make up for their disadvantages.

EDIT: I should mention that I haven't read the article in the OP, I'm just giving first thoughts based on the quotation.

[SMadsen]

The start of the article sounds more like an appeal to the general American connotation of evolution shaped by an 80% consensus of the you-know-what idea. To me this is a rather indifferent as far as human evolution is concerned and as the article progresses, the focus fortunately shifts to more important issues.

However, the start is of course interesting enough, but as Dominic says, only as far as socio-political views are concerned. For example, in my half a decade here on earth I've never heard the claim that human evolution has actually stopped (except of course from religious nuts). I've heard plenty, though, that humans have defied natural selection but that has more to do with what we allow ourselves to call "natural" - or even biological - with regard to ourselves than it has to do with evolution as such.

For example, if termites develop a change in skills rather than a visible physical change, then we would say it was a biological change. If humans develop a change in skills rather than a visible physical change, we say it's a cultural development. Or even a technological development.

Dominic is right that this is based purely on a socio-political persuation of a notion of exceptionalism (unlike Dominic, though, I'm not so sure exceptionalism ows all that much to religion but that's another discussion).

From there, it's not all that far to assert that natural selection has been defied, simply because humans consider their own position to be outside nature. What it doesn't mean, of course, is that evolution has somehow magically stopped.

Anyhow. Although the article sporadically gets back to the notion that evolution has stopped for humans, there's some rather interesting info along the way. Thanks for the link.

[Michael]

That thesis seems perfectly logical to me. Evolution is nothing more than a reaction to changing circumstances and when those change more rapidly, evolution is bound to increase too. It's that or extinction. The whole thing is really that simple.
Yes, I agree with you entirely here. :agree:

(testing new smilies)

I suppose the claim that 'evolution had stopped' stems from politico-religious backgrounds. Such a statement requires a belief in exceptionalism for humans and/or a belief that 'progress', specifically technological progress, has some exceptionalist characteristic that would make humans immune to evolution. But it's that very technological progress that has increased the rate of change of environmental factors, and thus of any corresponding evolution,

That doesn't mean to say that current evolution would be catastrophic or revolutionary in nature. It would be as gradual as ever. Nothing carnivalesque is to happen to humans in the near future.
Actually, the claim that 'evolution had stopped' is only a paraphrase of a general theory that is held through academia regarding evolution. That is to say, that it has always been understood that evolution was a slow process that occured over long periods of time. Thus, for all intents and purposes, biological evolution is 'assumed' to have stopped, but that's only relative to our short human awareness timeframe (of only about 5000 years of recorded history). There's no specific theory that states that 'evolution is finished' or anything like that - except for some specific religious-political viewpoints.

I doubt there's a "politico-religious background" to claims that human evolution has slowed/stopped so much as there is an assumption that humanities' ability to rapidly evolve culturally has more or less rendered its much (MUCH) slower biological evolution obsolete.
Yes, this theory is also quite commonly held as well. It is complimentary to the one above.

However, the start is of course interesting enough, but as Dominic says, only as far as socio-political views are concerned. For example, in my half a decade here on earth I've never heard the claim that human evolution has actually stopped (except of course from religious nuts). I've heard plenty, though, that humans have defied natural selection but that has more to do with what we allow ourselves to call "natural" - or even biological - with regard to ourselves than it has to do with evolution as such.
Well, Greendruid has advanced a common form of the theory in one of the threads about modern society - that the human brain is physically 'wired' for for our hunter-gatherer lifestyle. Thus, you have encountered this 'claim'... :D

Indeed, a heck of a lot of our 'human' sciences is built on the assumption that human physiology is essentially 'static' to our time perspective, though the concept is rarely stated in such a bold way as to say 'evolution has stopped' (because to assume it has totally stopped is totally illogical). But it is a general or common viewpoint found in the human sciences - or it was when I went to school. ;)

That's why I think this potential scientific breakthrough could be VERY significant for a wide variety of scientific disciplines, though perhaps not in the more popular sense of the general theory of evolution.

For example, if termites develop a change in skills rather than a visible physical change, then we would say it was a biological change. If humans develop a change in skills rather than a visible physical change, we say it's a cultural development. Or even a technological development.
An excellent point to keep in mind here. Humans tend to use 'double standards' when viewing human vs animal behavior.

Dominic is right that this is based purely on a socio-political persuation of a notion of exceptionalism (unlike Dominic, though, I'm not so sure exceptionalism ows all that much to religion but that's another discussion).
As I noted above, some socio-political-religious notions of exceptionalism may be complimentary to this general theory, but I should think that several other ones object to the whole evolutionary thing entirely. And yes, an assumption of homocentric exceptionalism 'by default' ought not to be surprising to anyone. We are humans after all and inventing our culture is something we like to do. ;)

From there, it's not all that far to assert that natural selection has been defied, simply because humans consider their own position to be outside nature. What it doesn't mean, of course, is that evolution has somehow magically stopped.

Anyhow. Although the article sporadically gets back to the notion that evolution has stopped for humans, there's some rather interesting info along the way. Thanks for the link.
I figured the article was a reasonably good report on the topic. :shrug:

Enough for us to discuss the topic anyway and that's the main point isn't is?

Anyway, I do think this bit of 'science' if it holds up in replication with other future studies, may have some rather significant impact on the human sciences - for the reason that I've given above. The idea that human eviolution may be changing at such a rapid pace is a rather revolutionary idea (though not entirely radical). ;)

[Dominick]

From experiences in the fields of physics, astronomy, cosmology et al I have zero confidence in articles such as this, so I tracked down its origin. It turns out that the article is largely based on a recently published book by Henry C Harpending. You know, a book that needs sales ;)
But there are also actual papers on the subject, though a few years old, that are accessible : http://www.pnas.org/content/104/52/20753.full.pdf+html and http://dx.doi.org/10.1016/j.meegid.2005.04.002. I'll get back on this after reading those.

Edit : the latter one isn't free either :mad:

[SMadsen]

And yes, an assumption of homocentric exceptionalism 'by default' ought not to be surprising to anyone. We are humans after all and inventing our culture is something we like to do.
Yes. If I had to ponder it, I'd say that it's exceptionalism that gives rise to religion rather than religions giving rise to exceptionalism. That of course belongs in the religious section, though :)

Anyway, I do think this bit of 'science' if it holds up in replication with other future studies, may have some rather significant impact on the human sciences - for the reason that I've given above. The idea that human eviolution may be changing at such a rapid pace is a rather revolutionary idea (though not entirely radical). ;)
You're right that it might give rise to some rather revolutionary ideas .. as some particular themes with pretty distorted but allegedly scientific origins have been known to in the past :)