Races may be defined as populations which differ in their gene frequencies. The frequencies of nonadaptive traits, such as hair color and blood types, may have gradually changed in small, isolated populations during prehistoric times. Today, these genetic differences are reflected in different racial populations. A blood in the Blackfoot Indian population of the northern United States and Canada. Basque people from the Pyrenees Range between France and Spain have predominantly Rh negative blood, while this blood type is relatively uncommon among Asian people.
Genetic drift can also result in the loss of genes from a population.
When populations become greatly reduced in size, some genes may not be passed on to the next generation. As a result, genetic variability may be severely reduced in succeeding generations. Protein analysis of the pines in Torrey Pines State Park show practically no variability between individual trees. This could seriously threaten their survival if the climate changes significantly. For a simplified demonstration of genetic drift, make 24 random matings from a container filled with 24 red beads and 24 white beads.