Re: Humans Have Stopped Evolving
Originally Posted by
Bruce
->
Sorry but that shows a complete lack of understanding of the process of evolution.
'Survival of the fittest' does not refer to living longer but whether a trait allows an organism to survive better than one without that trait which over time means that those with that trait will tend to reproduce more and those without tend to reproduce less.
It doesn't matter about living longer because evolution relies on reproduction. Humans don't reproduce longer but they do currently (in the west) reproduce later which is particularly important for mutation. What effect that will have long term who knows?
As for the rest there is no evidence that human intelligence is decreasing not that intelligence is needed for the survival of a specie - bacteria do very well thank you.
Selection can be as you say, a trait that is more successful, better adapted in the habitat that the plant or animal exists in. As the habitat changes the traits that work change.
This can be slow or fast. If there is a catastrophe that eliminates much of the life, then surviving species will fill in the niches that were opened up by that event. Like what happened during the Cretaceous Extinction.
When the dinosaurs became extinct, mammals and birds (left over dinosaurs) took over the "newly" opened habitats and developed traits that worked in those habitats.
Evolution is also slow and incremental. But it is constant and species become extinct or change no matter what.
Humans have not been on earth very long, in fact humans are not even a speck in earth's history.
We have done a lot of changing of habitats by our industry and large population. We have eliminated many species because of these activities. That is in just a speck of geological time.
It's possible that we have changed things enough to insure a change in our situation and we might shrink in population rapidly. In my opinion that is very likely. I don't think we will become extinct in the short term. We have degraded our food sources, water and air. Perhaps enough to create a mass famine, degradation of infrastructure and wars. We will definitely will suffer great consequences.
It might happen in fits and starts. It might take a few generations. It might happen rapidly, even by our standards.
Perhaps some humans will adapt to these changes and succeed or survive for some time. We might evolve into a different species entirely or become extinct.
The earth does not care, it goes on and the geological processes go on and life in general adapts to these things. Life will be on earth long after we are gone. All of our structures and monuments will disintegrate and we will become fossils or remnants in the stratified layers of earth's geology.
Have a nice day!
After reading the initial post, Sir David is wrong in my view. Even if there is a "pause" so to speak we are evolving. Because there is a person that is adapted for the next change in the environment. Let's say transportation, rapid transportation across oceans and from continent to continent collapses. So human populations become isolated. Then adaptation begins again. Humans become more location specific. There are many possible futures and man is still evolving. Could be (take) a couple of thousands of years but that is nothing in earth time.
I say it is happening now. Right under our noses.