You searched for: “orthogenesis
1. a biological principle that the evolution of an animal species is in a given direction, governed by intrinsic factors, and independent of external factors.
2. The doctrine that the phylogenetic evolution of organisms takes place systematically in a definite direction and not accidentally in many directions; variation is predetermined by the germ plasm.
This entry is located in the following units: geno-, gen-, genit-, gener-, -gen (page 18) ortho-, orth- (page 4)