Orthogenesis (Gr. Orthos - Direct, Gennan - Generate)

Orthogenesis

Orthogenesis (from the Greek words orthos - “straight” and gennan - “to generate”) is evolution moving in one specific direction, “straightforward” evolution.

The term "orthogenesis" was introduced into biological literature at the end of the 19th century by the German zoologist and paleontologist Theodor Eimer. According to his ideas, the evolution of species obeys certain laws and follows a predetermined path.

Orthogenesis presupposes the presence of internal driving forces that determine the direction of evolutionary development regardless of environmental conditions. It was believed that these internal factors set evolution in a strictly defined, “direct” direction.

As evidence of the existence of orthogenesis, examples of “straightforward” evolution in the history of certain groups of organisms were given - an increase in body size, a progressive complication of the dental system, etc.

However, later the concept of orthogenesis was criticized, since it could not explain many facts and patterns of the evolutionary process. Currently, orthogenesis is rejected by the synthetic theory of evolution, according to which the direction of evolution is determined by natural selection depending on environmental conditions.