30 



BIOCHEMICAL SYSTEMATICS 



B 



1 



Fig. 2-10. Two ways by which parallelisms can develop in evolu- 

 tion Parallel selection is assumed in each case. (A) Independent 

 parallel mutations at homologous loci. (B) Hybridization foUowed 

 by segregation in the direction of one or both parental species (Bi), 

 or followed by backcrossing, viz. introgression (B2), V. Grant, 

 Natural History of the Phlox Family. Systematic Botany. Inter- 

 national Scholars Forum A Series of Books by American Scholars, 

 Sciences 1. The Hague: Martinus Nijhoff, 1959. 



