Re: What are the benifits of humans interbreeding with near relatives??

Well, with humans, inbreeding is not good at all. Through the ages 
humans have come to realize that inbreding causes detrimental 
effects. This is mainly due to the fact that we have two copies of each 
gene in our cells.

If a brother and a sister are heterozygous (in this case heterozygous 
will mean that we have one good allele and one bad allele) for a 
particular gene they will probably live healthy lives with respect to 
those genes. Remember an allele is an alternate form of a gene. 
However, if the brother and sister (or any close relatives) were to 
mate, there is a good chance that their offspring would contain 2 
copies of a detrimental gene that may exist within their family blood 
line.

So, when close relatives mate they increase the chances that a 
particular 'bad' allele will appear twice within their cells. Since, there 
is no 'good' copy of an allele for the cells to rely on these alleles may 
end up causing a disease or disorder for the organism in question.

Pure-breed pets are full of disorders. Many pure-breed dogs have 
bad hip joints. The term "pure-breed" doesn't say anything about how 
many detrimental mutations that breed has. Pure-breed animals are 
only pure with respect to the characteristics the breeder has chosen. 
For example, if you want a dog with long hair you may look for a dog 
that has been purely (soley) breed for having long hair, nothing else 
matters. 

The sad thing is that a dog may be a pure-breed for a set of features 
but end up having disorders or 'bad' features because the breeder 
was not concerned with them. Some dogs and cats continually 'cry' 
because they were breed to have 'flat' faces. These flat faces squish 
the tear glands to the point that it appears that the animals are crying.

-Hope this Helps
-Mike