That is quite possibly one of the weakest and least thought out arguments I have ever heard. No offense, since you don't appear to be racist in any other way.... so let me explain.
The genetic difference between a chimp and a silverback does not even allow them to produce offspring, as far as I know anyway... even if they could produce a hybrid it would likely be sterile, like a mule (horse / donkey). Humans of all races are genetically similar enough to produce fertile offspring... the total genetic difference between a white and a black person (or between any two races) is incredibly small.
"Subspecies are closely related by definition, and human races appear to be less genetically distant than the major phylogroups of many other species.[113] While FST values for neutral variation are by no means negligible from a population genetics point of view, it’s significant that the overwhelming majority of genetic variation is found within populations, reaffirming the importance of treating people as individuals. It’s also significant that the FST value for the most prominent racial trait - skin color - has been estimated to be about 0.60,[114] which means that the visible variation between races greatly exaggerates overall genetic differences."
http://www.goodrumj.com/RFaqHTML.html
* Fairly interesting read
I can't believe this argument still exists in modern times with all of the knowledge we have about genetics.