Was there a "sensitive moment" in human evolution history which might have changed the course of evolution?

Question

Like a moment.... where there was a chance that we could be having six fingers/ three eyes/ one ear etc if one thing would have gone wrong.


let your imagination fly

Answer 1

One obvious moment has to be the extinction some 25,000 years ago of Homo neanderthalensis, Neanderthal man, displaced by Cro Magnon man, the earliest known European examples of Homo sapiens sapiens.

Another moment may be said to be occurring now, as sperm counts continue to drop in males in modern countries with co-occurant drops in population growth rates to below "replacement"rate.

The next catastrophic world pandemic may very well drastically alter the course of the human tide.

Of course, that big space rock may finally arrive and settle our hash but good.

Answer 2

Yes, there were undoubtedly many such chance moments.

You can look at that in terms of paleogeology and paleoclimatology: the warming trend in Asia 12 million years ago allowed descendants of Ramapithecus to migrate into Europe and evolve into a diversity of great apes, and then the cooling trend that started 10 million years ago pushed the ape ancestors of gorillas, chimps and humans to migrate back to Africa. Further, the drying out of East Africa 5 million years ago helped to further result in reproductively isolated groups which became humans/chimps.

You can look at it in terms of nucleobase transcription errors in the genome. Humans have some 70 genes involved in intellectual functiong which are different from those of chimps; but only 12 of those genes account for 95% of the variance in chimp/human intellectual functioning and just 3 genes account for some 75% of the difference.

Answer 3

Sorry, but doubtful. The basic vertebrate body plan is well established. Even key features like the opposable thumb are not uniquely human.

Probably the key moment was that a small - very small - population didn't get wiped out in a drought or something very simple.

Answer 4

Well, if Eve (the real Eve, who lived 140,000 years ago), had married Billy instead of Joe, we all might have better teeth today.

But alas! Billy, with his good teeth, never had any kids. So we have to put up with our bad teeth and trips to the dentist.

Sound funny, but it's true. The teeth of modern humans are one of the bad choices of human evolution. We got just too many of them, in too small a jaw, and they get decay too easily. Ask any dentist. Most other animals don't have the problem with teeth that humans do.

Answer 5

Yes there indeed was!. And it was the period when human language developed expressions to symbolise ownership. Word like I , mine and its varieties of possessive cases created distance between members within one's own surroundings and between communities of differnt language speakers. If you think carefully you will agree that the advent of lingustic experience, instead of forging amity between human beings have created rivalry. Therefore the moment of evolution in human societies which started dissention was the time when we began using the language!!

Answer 6

Periods of low population with extreme environmental stress are the pressure cookers of eveolution.

Answer 7

Evolution is a mirage.
All energy forms develope
around their own centers,
which are a series of genetic
frequencies triggered when
quarks explode.

We don't come from our parents.
We come through our parents.

Here's one for your imagination:
Where did your ancestry get your
genes, if they didn't get them from
you?

Answer 8

You're talking about genetic disorders which is an everyday occasion already...

Answer 9

I think that this could happen at anytime with all the chemicals, pollution and the other stuff out there.

Answer 10

if u had one ear ...three eyes and sis fingers..would u like them...