Expert: John Shea - 9/13/2004

Question
Hello,

I read in the book "White Racism: The Basics" that everyone is at least 1/50th of a cousin to each other. I was wondering if that is true and if so how it is explained; how can people of different races be related? Thank you.

Answer
Dear Jade
I'm not sure about the 1/50th estimate, but all humans are very closely related.  We are escended from a last common ancestor who lived in Afria no more than around 200,000 years ago (an hypothesis based on the analysis of variation in mitochondrial DNA and confirmed by discoveries of human fossils in the appropriate range of dates, 100,000-200,000 years ago in Africa).
Race is an artificial classification of human variation that subdivides a continuum of genetic variation. It probably made sense to European explorers traveling by ship, -stopping in at ports widely separated in space created the illusion of vast differences between populations.  Had they traveled by land, changes in human appearance would have been too subtle to notice. The notion of race as a meaningful concept persists in non-scientific circles, but biologists who study humans pretty much abandoned it as a serious way of describing human variation nearly 40 years ago.
People can look very different (skin color, stature, hair texture) and yet be very closely related genetically.  This is because the morphological features that define "races" are not linked to reproductive behavior. The ultimate test of this that all living humans can interbreed with each other and produce viable offspring.
Cheers,
John Shea