Beauty by Race

[KendallJ]

Actually it is your analogy to hybrid vigor that is false.

For many genetic diseases, it requires the organism two have TWO copies of defective genes (ie. one from each parent) in order for it to be active. One example I can think of would be the relatively high rate of sickle cell anemia among the black population in the United States. This is obviously much more likely to occur among a smaller gene pool. The concept of HYBRID VIGOR doesn't apply here because in dog breeding, many of the desirable attributes aren't actually genetic defects, but rather normal phenotypes produced by selective breeding. That is why in the case of cross breeding dogs, it is difficult to control the expressed phenotypes for solely the desirable attributes.

So what you should have said was that the health aspect of cross breeding among races led to lower probability ONLY for genetic diseases that are recessive in nature.

Your next task is to validate your claim that this is true of "MANY" genetic diseases, which I don't think it is. Genetics are a component in most diseases (excepting infectious disease) and even health issues, and very few of them exhibit the straight "recessive to turn-on" sort of mechanism of expression. Many genetic issues result from the over expression or underexpression of various proteins and those are not covered under your senario. It is identical to the breeding phenotype senario you describe above, and hybrid vigor as you've described it is a false concept for ALL of those genetic conditions. Cross breeding among different gene pools does not necessarily provide higher levels of health.

[Moebius]

Your next task is to validate your claim that this is true of "MANY" genetic diseases, which I don't think it is. Genetics are a component in most diseases (excepting infectious disease) and even health issues, and very few of them exhibit the straight "recessive to turn-on" sort of mechanism of expression. Many genetic issues result from the over expression or underexpression of various proteins and those are not covered under your senario. It is identical to the breeding phenotype senario you describe above, and hybrid vigor as you've described it is a false concept for ALL of those genetic conditions. Cross breeding among different gene pools does not necessarily provide higher levels of health.

Yes I realize that genetics is a component in many diseases. I am not suggesting that mixed-race people are some sort of super human breed that is immune to diseases. Although once again I'd like to make a distinction between having the various genes that increase the likelihood of heart disease or cancer or what not, and having a straight up genetic defect -- many of which ARE recessive in nature. How many is many? Well that's pretty subjective, so let's just agree that being biracial does hedge you somewhat against those kinds of conditions -- at least when compared against either side of the parent population.

That said, I am not really interested in debating whether biracial people are in fact more healthy. That is only tangential to the fact that one research resulted with two groups of people -white and Japanese- both identifying biracial faces as more beautiful. Better health is offered as one plausible explanation, which may or may not be the true (or only) reason. However, note that in the case of sexual selection you do not need to actually BE more healthy, you just need to LOOK more healthy. Read the article I linked -- it's short and fairly brief. Agree or disagree, I just wanted to provide a relevant perspective.

[Sir Andrew]

Her comment seems logical, but keep in mind that most white Americans are in fact a mixed breed

[Steve D'Ippolito]

...as is almost everyone, you just have to go back far enough.

With ancestry in Sicily, I am sure I have some relatively recent (as in sometime in the last 3000 years--go back far enough and we are all Tanzanians) African ancestry. More recently my ancestry is from all over Southern and Eastern Europe, and the Eastern European almost certainly would have some Tatar and Mongol in it; likely some Uralic (that's an old group that today would encompass Finns, Saami, Estonians, Mordvin, Mari, Komi, Udmurt, Karelian, and Hungarian) as well, as they and the Slavs had have quite a lot of contact. (Geez, I may even have some Scandinavian in the tree (from the Vikings).) And I won't even *start* on my Jewish ancestry, which is most likely a mix of Hebrew and Khazar.

The short answer, from the standpoint of people who take such things too seriously, is I am a mutt. The correct short answer is I am a human.