Does Interbreeding and Domestication Increase or Decrease Genetic Diversity?

[diatom]

If all the different races or cultures of mankind began to intermingle and reproduce with one another until there was just one homogenous culture or race, would the genetic diversity of the species as a whole have lessened or grown. Would the species as a whole be more robust before or after the homogenization occurred?

I realize there's probably something wrong with saying "one homogenous race" because it's not really clear what that means, but my question was inspired by someone else's comments made on another site, so I don't know how else to phrase it.

Is there more genetic diversity within the wolf species (including domesticated dogs) now that dogs have been bred by man? Is there more genetic diversity within the wolf population (not including domesticated dogs) than there is within the population of domesticated dogs?

 

[Ryan_m_b]

If all the different races or cultures of mankind began to intermingle and reproduce with one another until there was just one homogenous culture or race, would the genetic diversity of the species as a whole have lessened or grown. Would the species as a whole be more robust before or after the homogenization occurred?

I realize there's probably something wrong with saying "one homogenous race" because it's not really clear what that means, but my question was inspired by someone else's comments made on another site, so I don't know how else to phrase it.

Is there more genetic diversity within the wolf species (including domesticated dogs) now that dogs have been bred by man? Is there more genetic diversity within the wolf population (not including domesticated dogs) than there is within the population of domesticated dogs?

You are asking two very separate questions.

Firstly regarding humans; "homogeneous race" really doesn't make much sense to me. We are already one species with pretty low diversity and we do intermingle and reproduce. However to answer your question if we were all one ethnicity then yes our diversity will have gone down.

Secondly I'm not an expert on the subject but I know that through domestication we have caused the speciation of http://en.wikipedia.org/wiki/Origin_of_the_domestic_dog#Specialization", so yes we have increased their diversity.