Assuming the Evolution Theory to be true, could it be...?

Question

That mankind evolved from several lineages in parallel, instead of the one line of possible ancestors so frequently shown

Perhaps if different people evolved from different species of apes, or whatever, that would probably explain a lot of physical, structural and/or other differences between people in our present day world?

Answer 1

There is a theory that when our common ancestor split with chimps that there were several million years where the species interbred forming hybrids.  I am skeptical of that particular theory but it is certainly possible.  Sometimes speciation, where species form separate species, is not perfect, and there might be other similar examples in our past.  Typically, there is what might be thought of as a line of evolution, a branch that leads to one species, but it is actually from a large diverse population so to think of it as a single line or branch is not quite accurate either.

Answer 2

1) very interesting

2) while it might be possible I would doubt it as the genetics of humanity are way too close to be from different lines

3) There is an idea called the Bottleneck Catastrophe that is gaining support under new evidence suggesting that most of early humanity died off and that basically all of humanity today is from one surviving tribe....it is still in its very early stages of being worked on so not saying this is proof but an idea that would relate.

Answer 3

The 'Recent African Origin' theory, the one that says we are all evolved from a small group of Africans,has some major problems with it. There's mounting evidence from study of the X chromosome that we do have some 'other lineages' in our ancestry, to explain our racial differences. Some of the X chromosomes separated from the African ones over a million years ago, and can't be found in Sub Saharan Africa at all.

http://mbe.oxfordjournals.org/cgi/conten...

There's very little internal structural difference between groups of humans, no matter how far apart they live, barring Pygmies. Now, there is a case for classifying Pygmies as a sub-species because they are so different, not just in height, but in lifespan (24years, menopause in the late teens).

http://www.physorg.com/news117456722.htm...

And I got a thumbs down for that because...?

Answer 4

Evolution isn't a straight forward linear process.  A species will often have discreet populations of individuals that are isolated from the others by behavior (nocturnal vs diurnal), physical traits (chihuahua and Great Dane), or geography.  The less the degree of isolation, the more likely these are to interbreed, and vice versa.

If the isolation persists long enough, mutations will accumulate in one or both to the point where they can still interbreed but will produce sterile offspring.  At this point we say that speciation has occurred.

Equines provide a good example.  Horses, zebras and donkeys are all separate species but can all interbreed.  Horse + donkey = mule (sterile).  Horse + zebra = zorse (sometimes sterile).  Zebra + donkey = zedonk (usually fertile).  if zebras died out, horses and donkeys would go their separate ways evolutionarily, because zebras are an evolutionary missing link.  This is really how missing links function; within a differentiating group of closely related species at a point in time, rather than across points in time.

We almost certainly did the same thing, while we were sharing the planet with other closely related hominids, but at some time divergence and isolation prevailed and we became a truly distinct species.  

There seems to be good evidence that we went thru an evolutionary bottleneck and were all very similar at one time.  As we moved into different habitats we once again began to differentiate and it's that episode that accounts for the differences we see now.  Had civilization not intervened, we would have diverged into several subspecies and eventually into several species.  native Tasmanians were so different from Inuits both in time and space that even tho they both lived in cold and difficult environments, they had accumulated enough in the way of mutations that they could fit a definition of subspecies, and were probably within 500,000 years of definite speciaton.  

Unfortunately, the Tasmanians were seen as so different from other humans that the Austrailian govt considered them a game animal and sold hunting licences and established a hunting season for them.  The last legal hunting was discontinued only 100 years ago, because there were none left except in zoos or as household pets.  The last one died in about 1918.

Answer 5

We can interbreed so we are closer than a horse and a donkey.

Answer 6

If that were true, then there would be several species of humans. There ISN'T. It's not about "different species of apes". It's about apes and man having a COMMON ancestor. Somewhere along the line, human beings and apes diverged. The so-called "Missing Link" is supposed to be the evidence needed to show exactly WHEN they diverged. Homo Sapiens adapted different physical characteristics depending on the areas they settled in as they moved out from Africa.

Unlike primates, human beings basically look the same, with only superficial differences.

Answer 7

It has been the case, but it appears that the last remaining lineage is ours... The last one was probably the homo florensis that died out about 12 000 years ago, but still some rumors say that those are still alive in some remote Islands of Indonesia!

Actually, there is a new theory that point out that the Neantherdal was another lineage, but evolve in combinaition with the sapiens to become himself a sapiens!! Look like those lineages have got the capacity to aggregate to each others!

Even if in theory it is impossible to breed outside your specie... Some environmental pressures may allow this time to times...

Answer 8

As you have phrased the question, no.  All human beings are members of the same species, H. sapiens and are most closely related to members of the genus Pan.

The view that comes closest to your question is the Multiregional hypothesis, which argues that these was one hominid migration out of Africa at about 1-1.5 MYA and that the selective forces for modern humans acted on all the human populations simultaneously.  

Smaller-scale adaptation to local environments caused the variations that some today call "racial" ("race" is a social concept, not a biological concept , but that is another topic for another time).  Some of those variations can be seen in situ from H. erectus through to H. sapiens.  See below for a more through look at the hypothesis.

wl

Answer 9

You can assume any theory is true, by definition a theory is not a fact. Here is a problem where we hold on to what we believe not what we see and know. Is evolution a theory or  fact. Do not let people tell you what the truth is, find it.