Inbreeding?

Question

I have read that Inbreeding leads to several complications.

if so How evoultion leads to a species with complex gene pool if the species evovles thoru inbreeding?. I mean to ask how from a limited gene pool one species can develop with huge gene pool.

For example All humans might have evloved from limited set of popluation. In that case inbreeding cannot be avoided and the genepool will be also limited. But we humans have huge genepool as of now. How could we have evolved into such complex organism. Or Humans evolved simultaneously in different part of the world?

Yep, i too thought of Simultaneous evolutions. But how come many such simultaneous evolution can lead to a same species in the world. (i.e) All are homo spaiens.

Answer 1

MUTATION!

This is why they say, mutation is the ultimate cause of variation. It is how every living being has evolved. Without mutation, there would be no basis for natural selection.

Ignore the first moron who answered.

Answer 2

No, it's not simultaneous evolution, and it's not mutation.

First, while inbreeding is not good, it doesn't have to be fatal. Many species can bounce back from even a small population (as we know from many species that have bounced back from the brink of extinction). In fact, if they all have some characteristic that provides some advantage, then it can accelerate evolution to have this small population genetically isolated from others who don't have it. Such a characteristic could be the result of a mutation, but it doesn't have to be ... it could just be a part of normal variation.

Second, there are many different ways that speciation can occur. The most common way is something called 'allopatric speciation.' It works like this:

Species have multiple subpopulations. If one subpopulation gets separated somehow from the rest, this can lead to speciation if they are separated long enough. The separation can be though a river separating a valley, a migration, a lake drying into two lakes (for the fish in that lake), a bad winter causing the subpopulation to lose contact with the other members, any of a number of things.

The isolated subpopulation could be as small as a handful of individuals, or it could be thousands. If it's just a handful, then yes, inbreeding can cause problems, but it doesn't have to be fatal ... a large population can bounce back from just a few individuals.

The important thing is that this subpopulation is genetically isolated for enough generations that even if they are reintroduced to the original species, they have lost the desire to interbreed ... and eventually they lose the ability to interbreed ... they are now two species (by definition).

As far as the human race is concerned, the evidence is that we split off from the other primates about 6 million years ago. Even if this was originally from a small troop of foundation individuals, 6 million years is more than enough to have reintroduced a substantially rich gene pool, with many different migrations that took us to all corners of the world, and in fact, several other speciation events that produced branches (like Neanderthal) that went exinct.

By the way ... there is no such thing as "simultaneous evolution" of a species (if by that you mean the simultaneous birth of the same species in multiple locations). A species is born once, and only once, by branching from another species.

Answer 3

Inbreeding concentrates deleterious rececive mutations (founder effect). The mitochondrial Eve suggests that there was a population bottleneck at the time she lived. Humans came through the bottleneck, and their populations grew. New mutations appeared and many disappeared. Some were favorable and became established in subpopulations. Interactions between groups allowed the favorable genes to migrate into other subpopulations. If they lived in areas where the gene was also favorable, it was more likely to establish itself over time. The isolation of subpopulations is well established. For example, native South Americans are all blood type O, and blood type B is all but unseen in the Americas and Australian native populations.

Answer 4

simultaneous evolution is the only logical answer...how else are we all different looking,,,,with different skin characteristics and physical features?...
or are you like the christian fundamentalists....when asked how the earth was populated if not by incest,,,they say: God allowed that kind of thing in order to populate the world...
Truth be known...smarter minds than mine have not come up with an answer...GOOD LUCK !!!!