Will we cease to be human if we can no longer breed with isolated tribes?

[binbots]

I was reading about a tribe in Africa and how they have not changed there ways for thousands of years. There are a few of these tribes left in the world. All these tribes can only have 3 outcomes. They breed with us, they go extinct, or they remain the way they are. If the third prevails then it is just a matter of time before we can no longer call ourlseves human. They will be the humans as they are the ones not changing. After some time we will not be able to breed with these people. (I hope no one takes any of this as racist). What I want to know is how much of our DNA has to be different before we can no longer breed. Have then been DNA testing on any of these tribes? Do we know how long this will take? do we already know what we are going to call ourselves?

 

[BoomBoom]

Careful not to confuse society/technology with genetics. I think it would be safe to assume that these tribes would be really no different from you genetically than your next door neighbor.

 

[binbots]

Yes that is true for bnow. But evolution says that a species divided by say a river will eventually become 2 different species. So we may be similair now but at some point we will be different.

 

[hypatia]

Maybe in another hundred thousand years we may be different. So its a little premature to come up with names.

 

[binbots]

Yes but some of these tribes have already been isolated for thousands of years. Wouldnt it be wise to start mapping this change now. If not now when. Are we that confident that it will take hundreds of thousands of years. what about taking a tribe from south america and another from africa. They have been separated for even longer. even if we find tiny differences would it not help in predicting how long it will take?

 

[russ_watters]

According to this timeline: http://en.wikipedia.org/wiki/Timeline_of_human_evolution#Homo

...our genus appeared 2.5 million years ago
...homo erectus appeared 1.8 million years ago and if you passed him on the street, you might not recognize that he's not quite human
..."archaic" homo sapiens appeared 500,000 years ago
...and modern humans 200,000 years ago.

These are the types of timeframes likely needed for new species evolution in humans. So a tribe that has been isolated for a few thousand years has a long way to go to have a substantial alternate evolutionary path. However, there are some minor yet more obvious traits such as skin/hair/eye color and size that have had noticeable variation over just a handful of generations.

 

[lisab]

Yes that is true for bnow. But evolution says that a species divided by say a river will eventually become 2 different species. So we may be similair now but at some point we will be different.

I'm not a biologist, but I think you need more than just separation. I think there has to be different environmental pressures on isolated populations, in order for those populations to diverge into different species.

 

[Andy Resnick]

I wonder why nobody has mentioned the pod people... maybe because it's already too late!

 

[zomgwtf]

Careful not to confuse society/technology with genetics. I think it would be safe to assume that these tribes would be really no different from you genetically than your next door neighbor.

You know that African tribes, are significantly more genetically different from one another than any other group of people? Even amongst Europeans you could have two Africans living right next to each other basically be more genetically different than any two Europeans with any two different origins. I highly doubt what you say is true.

This is a large support for the 'out of Africa' model. Africa has the greatest genetic diversity whereas native Americans have the least. Makes sense if you think about it. The amount of genetic diversity goes down as you follow our ancestors migration.

 

[MotoH]