Human intelligence and physiology still increasing, keeping up with technological and cultural advance?

Question

We've come a long way from hairy cavemen who managed to wield fire and survive in a harsh, predator-infested world. But, other than losing more and more hair and some other physiological body parts/functions, is the human race still evolving its intelligence and overall fitness (fitness as in overall genetic purity and resistance to diseases, (toxic?) chemical substances, radiation, and mechanical damage) like it has been for tens of thousands of years, or has our success eliminated the effects of evolution, now that even the weakest and/or less intelligent members of the human race have plenty of resources and possibilities to reproduce? Can our intelligence and fitness keep up with our society's advancement into the space age, or will the human race eventually perish out of accumulated genetical imperfections? What screening methods of evolution still apply to the human race, other than weeding out the obvious inheritable diseases? Is the human race going forward, or standing still?

Answer 1

Max, we are currently experiencing rapid population growth & natural selection does not occur during those periods.  Natural selection is often confused with evolution, which is a never ending situation.  During natural selection, something happens to reduce the reproductive or survival chances of a species causing a "bottle neck" through which only a few of the species will fit.  This may be some disease, climate change or other adverse situation that limits the survivability of a species.

Because those with an IQ of below 90 produce 3 times the number of offspring as those with an IQ of over 115, one might assume we are naturally selecting for a lower IQ, but scores don't seem to reflect this, as of yet.  This is a puzzle where the mitigating factor may be cultural rather than genetic factors.  We need more data on this & the way we measure intelligence.  

While we are still evolving, abeit in many differing directions, only a calamity of some sort will make the selection for the future of humanity... be it pure chance or some evolved characteristic can't be determined.

Answer 2

I liked mathildas answer. While I agree that human intelligence has gone up to do to better education and access to information via the internet I think people have become dependant upon technology to think for them more and more. I think this might eventually lead to the cybernetic human coupled with genetic enginering.

Intelligence is only one factor determined by DNA. Just because you're smart doesn't mean you have good DNA. I think Steven Hawkin is a prime example. In the next couple of decades I think we will see the emergence of artificial intelligence and this may play a key role in how humans develope. In the mean time I think over population will eventually force conflict and those with the most and best technology will likely prevail.

Ultimately in my opinion I think technology will determine our future evolution and that even though we will become increasingly more dependant upon it I think our over all intelligence and mental functioning will grow. I also think that technology will allow us to combat cancer and disease.

We as a species have taken a much more excellerated path. Normal evolution takes a minimum of decades to emerge, and thats just simple things like behavioral trends. We with our intelligence have made it so that we will evolve far more faster than most other live forms. (save the common cold and fleu bugs ;-)

Answer 3

with any luck evolution will screen humanity out of existance...

they are a unpleasant creature...

Answer 4

I think our success has limited evolution, but we are also learning to evolve purposely.  We can now have our eggs and sperm tested for genetic diseases so that we can eliminate some accumulated genetic imperfections by choice.  Cool, huh?

Answer 5

Ed...The average IQ of the western world has gone up by 30 points in the last hundred years(Flynn effect), it's probably hidden any dysgenic effect from low reproductive numbers in the high IQ crowd. Also,contraception has only been a major force in the past 50 years or so.

We're are always evolving, more so now than before because the huge population gives more opportunities for beneficial mutations to occur. Lactose tolerance is still in the process of spreading itself, it's only a few thousand years old.

I'd imagine a little mild genetic engineering will creep in by embryo selection in the next couple of decades, picking the best of a few hunded conceptions, like in the story Gatttaca. It would counteract any problems from the sickly surviving. Unnatural selection.