This is Komen, who may hold New Hampshire state records for both the fastest 5K (17:18) and the fastest unauthorized consumption of a large pizza (about 90 seconds). But more interesting to most is how he came to assume the most popular — but not the most likely– hue of America’s most popular breed.
So the breakdown goes like this: If left to mate at random (and this is decidedly not the case), 3/4 of Labs would show color (i.e., black or chocolate) and 1/4 would be yellow. Of the 3/4 showing color, 3/4 of these would be black and 1/4 chocolate, so overall, (3/4)*(3/4) = 9/16 of dogs in the population would be black and (1/4)*(3/4) = 3/16 would be chocolate.
Also, without knowing anything about individual dogs’ genotypes, we see that two yellows can only breed yellow puppies, two chocolates might produce either chocolates or yellows, and blacks might produce pups of any color. Of course, a knowledgeable breeder would be able to guarantee the arrival of a given color after a number of generations through a simple enough process of manipulation.
This site gives a basic, illustrated breakdown of the predicted results of matings between all permutations of Labs; below, courtesy of Labbies.com, is a 4 x 4 Punnett cross between a pair of F1 (diheterozygous) dogs.
One of these days, I’m going to have three Labs, one of each flavor. I’ll name the chocolate one Ebony, the black one Tawny, and the yellow one Cocoa, ’cause I’m funny like that, and no one except for the dogs themselves will be able to keep their names straight.