The nagging question about evolution?

Question

If we evolved from ape-like ancestors, why did that evolution stop? Why don't we still witness apes or ape-like species evolving into humans still today?

Answer 1

There are three problems with your question.

First, why do you imagine that evolution has "stopped"? This is like standing in front of a tree for ten minutes and concluding that it has stopped growing.

Second, apes or ape-like species that we see today are not precursors to humans. It is a common misinterpretation of evolution to think that apes are "intermediate forms of humans" or "unevolved humans". They are not. Apes are *fully evolved apes*. They are every bit as fully evolved as we are. They are every bit as adapted for their environment as we are for ours.

Third, it's not like the "goal" of evolution is to produce humans. Just because one branch of primates evolved to be humans, doesn't mean that *all* branches are doing, or ever will do, the same.

Answer 2

This comes from a poor understanding of how it worked. Think of this classic analogy:

In the modern era, there was a very large emigration of people from Europe and, to a lesser extent, Asia to the new world. These people came to be known as Americans, and they developed a culture that differs in some respects from that of their ancestors.

Now, we certainly don't ask the question "If Americans have European and Asian ancestors, why did that change stop? Why are people still European and Asian today?"

I think this is a useful analogy, but it's not a perfect one. The change from European to American isn't a form of evolution. Moreover, modern Europeans can still cross the Atlantic and become American.

Evolution is different. First, we didn't evolve from chimps. We just have some common ancestor with them. Second, chimps have evolved from that common ancestor just as we have. Third, to expect all the different steps between that ancestor and modern human beings to be repeated in chimps (who've already moved off in another direction) is like expecting two babies born to different parents to both turn into identical adults. There are practically infinite evolutionary paths open to any organism; chimps could evolve to become just like human beings, but that would just be one in an uncountable number of possibilities. It's about as likely as a coin coming up heads a billion times in a row.

Answer 3

Why do you think it has stopped? Our ancestors were a lot shorter than us even 500 years ago. Evolution is very slow but still going on. We don't see other apes or ape like species evolving into humans because as they evolved we killed them. They were competition. The last one died out about 20,000 years ago and was called Neanderthal.

Answer 4

Fair question as is the "missing link". You possibly know one of the "missing links " was fictiocious- guess it takes all sorts..
After all we have history of sorts going back~6,000 years, during which time the Egyptians who were the main okes have dropped off the map. Abraham's descendants are the only one who have always been in contention. Guess there has been some development, as in Southern Africa there was only the spoken word until ~300 years ago while Egypt & China had the written word & intelect 6,000 years ago at least!
However it is fair comment that "human physiology" has not changed a jot. That is why we have the problems we do. We were "designed" for fight or flight & to use or bodies to get our food - as is stated in Genisis when Adam was barred from Eden. We now have found other ways, in concequence we do not eat enough as we do not physically work enough & we are under nourished unless we take suppliments!
There is evidence that the celeocanth was the predecessor to some land animals, but the human link in the evalution chain is to the best of my understanding still missing.

Answer 5

There are many reasons one can think of.
I will give you 3 main ones.

1. 6000 years of human civilisation, is nothing compared
to the vastness of time in which evolution occurs.
And the time passed since Darwin amounts to nothing at all
in evolutionary terms.
So to say that evolution has stopped is a very premature
conclusion.

2. The idea that the apes of today would evolve into something like human beings is completely wrong.
Is is based on the Idea that us humans,are the inevitable
end result of evolution, the thing evolution has been 'working
towards' so to say. This is complete nonsense!!.
Evolution is blind,it has no goals! it just happens,and
we are just a lucky bunch of so and so's that happened to
evolve the way we did.
There is no such concept as progress, it's adaptation to
( changing )circumstances that drives evolution.

3.There is a theory called 'Punctuated Equilibrium'
which sort of states that unless a species is under evolutionary pressure ( Changing Habitat for example )
it is not very likely to change as it is already well adapted
to the circumstances it lives in.
( sort of ; If it ain't broke, don't fix it )
Chimps / Gorillas / and Orang Utans are perfectly adapted
to living in the Forest and there is very little pressure for
these species to change at all, so evolution may be even
have slowed down to a crawl and become unnoticable for
hundreds of thousands of years.

And before you give me the argument, that they are under
pressure now and nothing seems to be happening.
That is because us humans are cheating them out of existence,it may take hundreds of generations for them
to adapt, and we'll have them properly killed off before they
have a chance to react.
You can't duck a bullet at point blank range.

Answer 6

evolution didn't stop. Its still happening today, in apes and humans and all other living things.
Some organisms change faster than others and changes can occur quickly (geologically speaking ) eg over a million years or so.
The evidence of the earliest human like "creature" is about 10 million years ago...so its been while since we were more ape like than human like. This is the earliest example of a animal able to walk on 2 legs, which the apes of today are unable to do (normally)

There have actually been quite a few different human-like (homonids) animals found, most of them in Africa, and all but us are here today.
They are mainly divided into about 3 genera. Australopithicus, paranthopus, Homo, but some even earlier genera are Ardipithicus, Orrorin and sahelanthropus.
There are about 20 different species of homonids that we have found and not all were directly involved in leading tp us, some were evolutioary dead ends eg Parathopus

Quite a few of these species were around at the same time as other ones too!! The last being H.neanderthelensis (neaderthal man.....not a direct link to us, but a relative). We know neaderthal man was around in Europe during the ice ages and it was well adapted to it, being sturdy, big nose to stop cold air getting into the lungs etc.
But the early H.sapeins (also called Cro magnun man) started to arive in the same areas as neaderthal man. Like with any other species, no 2 species can survive in the same habitat......1 will success over the other (the other will move away or die out).
H.sapiens is a pretty resourcful and adaptive animal. We were able to survive better than the neaderthals, which slowly (over thousands of years) reduced in number and eventually dies out. There is also evidence of "hybrids" between H.sapiens and H.neaderthalensis!!!
Our features have changed even more since the early Cromagnum man, in particular we have got taller (and still are, we see eveidence in Japan where milk products have reduced in price in the last 50years and are actually getting taller faster than in other places.....even in western coutries a very tall woman 40-50years ago was about 5-10 or 5-11....today we get more even taller, more often)
Our chin is more pronounced (receeded chin is a feature of all other homonids), we have a more forward protruding brain (whereas earlier ones have a more sloping forehead and protruded brow ridge). There are other more subtle things as well. If you see the evidence with gradual changes in the earliest millions of years ago (eg teeth, muscles (in head and body), skeleton shape, height, knee/hips (for walking on 2 legs), brain size etc etc etc.

Answer 7

Because evolution is an incredibly slow process. It takes long periods of time for one species, or a subset of the population of one species to evolve into another, distinct species, people do not always agree how long but hundreds of thousands of years at a minimum for the changes you are describing.

Answer 8

Yes, evolution is extremely slow and much of it is in response to environmental factors. You see evidence in areas where there is a nutrition deprivation or a need to adapt. A good example is how much taller people are today than a few hundred years ago. Thomas Jefferson and George Washington were over 6ft - which was very abnormal in their day. Today, that height is relatively normal. (But it does make me wonder about the added hormones in the food we eat. How is that going to affect our future generations?).

Answer 9

Humans are not the "next step" in evolution for modern apes. Humans, chimps, gorillas, monkeys, and other primates share a common ancestor.

Here is a simple, generalized illustration:
http://home.clara.net/rfthomas/papers/images/primtree.gif

Answer 10

Some species continue to evolve (such as myself).

Others, like the guy who broke into my car and stole my overhead DVD player last week, have probably quit evolving.