Evolution and Plumage Traits in Pheasant Hybrids, Phasianus x Chrysolophus

It has been amply demonstrated that hybridization affords an effective means for analyzing some of the problems that confront students of evolution and systematics. One such problem concerns the nature of genetic complexes back of those traits which serve to distinguish between related forms and another is the frequently encountered reticular distribution of traits that makes it possible to group the same array of organisms in several different ways; e.g., A, B, and C as AB-C, AC-B or A-BC. Such an apparent classificatory triad might reflect a misinterpretation, or it might be explained by convergent evolution, by enduring effects of past hybridization, or by the phylogenetic persistence of traits which early in the process of speciation became sorted more or less at random. There is always the possibility that hybridization may partially break down some of the established complexes and render their elements more accessible to apalysis. While work of this sort can usually be -carried out more quickly and efficiently with rapidly reproducing lower forms, it nevertheless is important to secure data whenever possible from higher, animals, even though the process is more laborious and the results less numerous. Various interspecific and intergeneric hybrdis have been studied in the pheasant family, Phasianidae, especially by Haigh Thomas ('14) and her associates, by