Reproductive Isolation in Humans?.......

[alextemplet]

I think reproductive isolation occurs on a very small scale, since certain people simply don't want to marry people without certain physical or cultural characteristics, but I doubt that anything biologically major will come of that. For example, I wouldn't want to marry a non-Catholic, simply because I don't want my children raised in a multi-religious home; however, I don't think my decision will lead to some major biological/evolutionary revolution.

[sachin]

Same in most of the countries too.........

Thats the reason I thought of that...

[David George]

well if the conditions what sachin said prevails then homozygosity will increase and so will the genetic diseases and each unit[country] will have its own species but this will take a very long time but if any mutaion occurs in the group then the whole unit can perish or diversify into a new species with rare cases having a positve gene.And that is why I don't want to marry any women in my caste,religion and race.

[mith]

We had reproductive isolation back when we didn't have modern transportation, and nothing really happened except created "races" if that archaic term can still be used. But I think with the rate at which we're growing and reproducing, it could very well be possible that we start having problems with infertility and other types of incompatibilities.

[alextemplet]

I've also wondered if the rising rate of migration and inter-racial marriages across the globe might lead to the combination of all races into one, global race.

[sachin]

"Global race"... right ..

[MrMistery]

not likely... plus, even if it were to actually happen, it would be so slow that global warming would kill us first...

[sachin]

not likely... plus, even if it were to actually happen, it would be so slow that global warming would kill us first...

[David George]

Yes global warming I am so afraid of it
Hope our earth's scientist will somehow find a way to save us.

[sachin]

Hope our earth's scientist will somehow find a way to save us.

You should say we, David, We should include ourselve in this mission....

We can not sit and wait another to do it for us... ....... we are science people and we have full power to do that for us and for other who are waiting for others to do that for them....... OK

[AstusAleator]

Amen

Also, I agree that globalization will just lead to more homogeneity among humans, which may or may not be a good thing.

I believe we've managed (so far) to break the cycle of speciation.
We adaptively radiated, and specialized to our local climates, but now instead of facing local extirpation due to overspecialization, we are mixing our genes back up.

However, a lack of "extreme" phenotypes may be a bad thing in the future, when global climate change begins putting new selective pressures on us. It could be that the one phenotype/genotype that could survive such change is being diluted by our ability to travel farther than we could before.

[sachin]

Ya; we require new selective pressure......