Quote of the day

G. Ledyard Stebbins, on p. 241 of "The role of hybridization in evolution," Proceedings of the American Philosophical Society 103:231-251, 1959:

We inevitably reach the conclusion, therefore, that introgressive genotypes not only persist indefinitely, but that also, like polyploids, they can migrate far beyond the areas in which they originated, and can actually survive after the non-introgressed parental species has become extinct.

(quoted in our own paper, "Dynamics of adaptive introgression from archaic to modern humans," available as free full text):