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Is Evolution Over In Humans?
BrianGa writes: "Is evolution over? Are current humans the final version? This
article presents a number of interesting theories, including the theory that
'Our species has reached its biological pinnacle and is no longer capable
of changing.' Professor Steve Jones believes this, in part, because
'human populations are now being constantly mixed, again producing a
blending that blocks evolutionary change.'"
I read the article just becase I don't like to reply without giving the benefit of the doubt.. but in this case it was a waste of time.
QUOTE: 'Things have simply stopped getting better, or worse, for our species.'
Then the Atomic Scientists wouldn't have a Doomsday Clock. And we wouldn't be worried about destroying our coastal cities with rising tides.
The article is only saved by Stringer who says the obvious, that 'Evolution goes on all the time. You don't have to intervene. It is just that it is highly unpredictable.'
I'd say that any mind that thinks evolution is over, is destined to become roadkill due to 'evolutionary' causes.
In our near future we have the prospect of mutations spreading which fight against aids, tropical diseases spreading north, and resistance to biowarefare or radiation. Somewhere along the way we will likely have changes in populations due to great artificial genes which can be passed on. Robotics and other technologies will enhance humans at some pace or another, there seems little doubt of that or you can read Hans Moravec if you are still unsure about that. We will have plenty of stresses on our populations and our genes, no worries about that. Homo Sap's going to have to advance a heck of a lot more for that.
The problem with a guy like Jones is that when people start to base strategies or policies on such delusions, we all lose out. Do you think we are losing no great artistic or scientific minds in the African tragedy of AIDS? Does it really matter if the makeup of populations change by one outliving the other, or being more procreative, or eating better, or what if they just ethnically cleanse, water war, bomb, poison, or otherwise do each other in? And are we all so homogenous now? I'd rather not consider myself as the least common denominator.
I think the battles of evolution require a lot of creative thinking to elucidate if you are thinking about your own time, and even then all bets are off. If anything evolution will accelerate as we become able to modify/improve our genes more quickly than the natural rate. And lots more people in the world will gain the means to exterminate those with genes they dislike. Finally, Natural Selection is always in operation. You can't turn it off just because increased mobility makes it difficult to measure.
Evolution is sort of like a saying of Buckaroo Banzai's: Just remember, wherever you go, there you are.
But this is also a problem. Educated and intelligent people have few children. Stupid people breed like mad. They not only pass along stupid in their genes, their environment sucks (no decent home fostering of learning so the kids have double strikes against them).
This actually argues for the statement that evolution is still in progress. (BTW, I think the article that started all this is as silly as saying "gravity doesn't apply to us now that we have rockets.")
The thing to note is that optimal reproduction is having as many offspring as you can afford to rear into your ecological niche. Flies can lay lots of eggs, because raising a baby fly is very, very cheap. Lions have orders of magnitude fewer cubs because raising baby lions (who must be defended, fed, taught to hunt, etc.) is a prolonged and time consuming enterprise. (Just try it some time if you doubt this.)
So the observed birth ratios are perfectly consistent with the notion that there is a lot more competition to be "wealthy" and "successful" than there is to be "poor"--and as a consequence, it takes disproportionately more effort to raise a successful child that to raise a luser.
Not only have we not "escaped evolution" we haven't even escaped this simple definition of "optimal" family size; Bill Gates could certainly afford to follow the "fly" strategy produce an army of tens of thousands ill educated brats that would assure his success in the gene pool, but instead (as we all do, on average) he follows the logic of optimal family size and chooses the "lion" strategy. Likewise, I had my first child at 40. I could have started at eighteen at had dozens of "I can count to twenty 'cause I ain't go no shoes!" kids, but I preferred to raise one that will be more likely to someday explain the zeta function.
-- MarkusQ
OK, let's reword this. Warning - there really isn't a PC way to say this, no matter how hard I try. I'm not being prejudiced here, REALLY, but the asbestos modem is out.
:-)
Defining success purely on the basis of bank balances is, indeed, daft. However, the poster was observing that those who are socially successful - the managers, the top people in their domains and so on - have fewer children, on average, than those who are less socially successful - the mediocre, those who do not stand out at all or those who only stand out by being worse at what they do than most others.
It is also noticeable that those who meet this criteria of social success have a higher mean IQ than those who do not. Anecdotally, I would observe that they also tend to have fewer congenital health problems.
To put it in purely scientific terms, the mean quality of the breeding stock amongst the socially successful is higher than amongst the socially unsuccessful, yet it is the unsuccessful who product more young.
The interesting question is what effect this has. The likely supposition would be that humanity as a whole would devolve because our current system was almost producting 'survival of the weakest'. However, I'm told that point scores on US military IQ tests have been consistently rising for some time. The distribution remains the same and the IQ scores don't change because they're generated fromt he distribution, but the raw scores on the graph are apparently rising...
All in all it's interesting, and the original poster certainly wasn't talking bunk, but I'm not sure what the end result is
Greg
(Inside a nuclear plant)
Aaaarrrggh! Run! The canary has mutated!