why do we not see evolution in humans?

[Data]

What about in terms of brain power, I'm sure progressing from domesticating horses to the Industrial Revolution to splitting an atom have something to do with our brains evolving. If I'm wrong, then tell me what would be a factor in that?

Wrong - that isn't evolution, it's just the case of accumulated knowledge. You'll find the people 10,000 years ago would be just as smart as you an I, if they were raised the same way as us. Every one of us goes to school for over 15-20 years, remember.

 

[ServantofTheOne]

does anyone have a reference for the avg size of humans throughout recorded history?

I would think that the size of humans would continually get smaller since there are fixed resources and large population growth. smaller people need less food to survive etc.

 

[Mad Arab]

Contrary to popular opinion, evolution has not stopped with humans. When you only consider natural selection, there are several gene frequency shifts that you can talk about to distinguish between modern urban humans and earlier human populations. For example, the genes that control insulin production (and give people who are no longer hunter gatherers diabetes) are greatly reduced in the modern populations (though with modern medicine that is less of an issue). The same is true for the genes that give resistances to many diseases (like plague). I am not sure how to factor other evolutionary processes than natural selection like "mate selection" into this, but I would think it too has and will always have a significant impact on our evolutionary heritage.

 

[Vance]

If 1470 [Homo habilis fossil ER 1470] was an ape, it would be a truly extraordinary one. The brain is far larger than that of any ape, with the possible exception of extremely large male gorillas. The braincase is far more rounded and gracile than that of any ape, and the brain has a human rather than an apelike pattern.- Tobias P.V. (1987): The brain of Homo habilis: a new level of organization in cerebral evolution. Journal of Human Evolution, 16:741-61.

Not to mention the fact that it was bipedal, and there is evidence it may have had rudimentary speech.

There is a reason why the hominids are not considered "apes".

 

[Vance]

Has anyone mentioned that 6,000 years is simply too short of a time period to see any noticable change even if evolution was in full swing?

 

[Physics_guy]

I would think that the size of humans would continually get smaller since there are fixed resources and large population growth. smaller people need less food to survive etc.

Resources are far from fixed. We produce vastly more food today than we did even 50 years ago and many many times as much as we did 1000 years ago. Resources grow drastically with technology.

 

[JohnR7]

smaller people need less food to survive etc.

They do? You have never seen my wife eat then, she eats more than I do, but then she works harder than I do. When I was doing construction work, I would burn up to 3500 calories a day. People trying to survive in the artic can burn up to 4500 calories a day. So, it has a lot more to do with how active you are.

 

[JohnR7]

if evolution is continuous why have we not seen it these last 6000 years?

The four minute miles comes to mind. People break records all the time.

 

[michabo]

Has anyone mentioned that 6,000 years is simply too short of a time period to see any noticable change even if evolution was in full swing?

I seem to recall a PhD who, judging by his name, was an expert in dinosaurs and evolution saying that we should expect to see about 1100 species of bats come from even a single pair in only six thousand years. He seemed quite critical of evoultion, so I'd trust him to give estimates that are very conservative.

 

[michabo]

If I'm wrong, then tell me what would be a factor in that?

Written language, scientific method, industrial revolution.

 

[brightlights]

yeah seriously avimov, evolution in education and theories that progress over time is far from ape to man.

 

[Split Rock]

Contrary to popular opinion, evolution has not stopped with humans. When you only consider natural selection, there are several gene frequency shifts that you can talk about to distinguish between modern urban humans and earlier human populations. For example, the genes that control insulin production (and give people who are no longer hunter gatherers diabetes) are greatly reduced in the modern populations (though with modern medicine that is less of an issue). The same is true for the genes that give resistances to many diseases (like plague). I am not sure how to factor other evolutionary processes than natural selection like "mate selection" into this, but I would think it too has and will always have a significant impact on our evolutionary heritage.

Another example is the ability of adults to digest the lactic acid in milk. This is a recent adaptation to the domestication of cows.

 

[Vance]

I seem to recall a PhD who, judging by his name, was an expert in dinosaurs and evolution saying that we should expect to see about 1100 species of bats come from even a single pair in only six thousand years. He seemed quite critical of evoultion, so I'd trust him to give estimates that are very conservative.

Well, you have to be skeptical of assertions *about* evolution from someone who is avowedly an opponent of it. I would be interested to hear his background.

The evolution of any species will depend on their reproductive rate and the amount of evolutionary pressure it is experiencing. We can see evolution at work even in our lifetime in rapidly reproducing bacteria under strong evolutionary pressures. In slow reproducing species (like humans), under much less evolutionary pressures (like humans given our greater ability to control our environment), I would expect to see much, much slower change.

Also, evolution expects species to often have very long periods of no change whatsoever when they are particularly well adapted to a particular environment that changes little.
.

 

[ego licet visum]

Immunities also. I can understand how if only someone who has been exposed to a disease becomes resistant to it. But what about their children? Why is it that the children of people that have developed certain resistances retain these same resistances? Even if the children are never exposed to the virus. Immunities must be genetic, and the developement and inheritance of them is an example of evolution.

And it is not just that children that have the same immunities as their parents because they were raised in similiar enviroments and got the immunites from being exposed to the same diseases all of their lives.

Why didn't Native American children pick up the same sort of resistance to smallpox immediately as the Europeans had after the Europeans had already exposed their society to the disease? If European children could pick the immunities up from simply being exposed to the disease from birth, why couldn't the native Americans?

 

[michabo]

Well, you have to be skeptical of assertions *about* evolution from someone who is avowedly an opponent of it. I would be interested to hear his background.

I must be feeling oblique today.

I was referring to that champion of hyper-evolution, Dr. Dino. For all of his critiques, he's not actually an opponent, but one of the staunchest supporters. He'll claim that evolution can work wonders even Dawkins and Gould would never dream of claiming.

 

[Freodin]

I have to wonder: what kind of changes do you expect? Six fingers? Wings? A second pair of arms?

 

[Sanguine]

A hopeful monster.

 

[Karl - Liberal Backslider]

yeah seriously avimov, evolution in education and theories that progress over time is far from ape to man.

Yes. And 6,000 years is far from five million

 

[Nathan David]

Immunities also. I can understand how if only someone who has been exposed to a disease becomes resistant to it. But what about their children? Why is it that the children of people that have developed certain resistances retain these same resistances?

They don't.

If European children could pick the immunities up from simply being exposed to the disease from birth, why couldn't the native Americans?

European children didn't "pick up" the immunities from being exposed to the diseases from birth. They inherited stronger resistance to the diseases.

 

[brightlights]

I have to wonder: what kind of changes do you expect? Six fingers? Wings? A second pair of arms?

anything