Wiktionary
n. (context biology English) A series of similar mutations in successive generations, producing evolutionary change.
Wikipedia
Orthogenesis also known as orthogenetic evolution is an obsolete biological hypothesis that organisms have an innate tendency to evolve in a unilinear fashion due to some internal mechanism or "driving force".
American paleontologist George Gaylord Simpson (1953) in an attack on orthogenesis described it as "the mysterious inner force". Classic proponents of orthogenesis rejected the theory of natural selection as the organizing mechanism in evolution for a rectilinear model of directed evolution. The term orthogenesis was popularized by Theodor Eimer.
With the emergence of the modern evolutionary synthesis, in which the genetic mechanisms of evolution were discovered, the hypothesis of orthogenesis was refuted, especially with Ronald Fisher's argument in his 1930 book The Genetical Theory of Natural Selection in favour of particulate inheritance.
Usage examples of "orthogenesis".
There are dozens of theories,--mutation, orthogenesis, Weismanism, Mendelianism, etc.
Or if Natural Selection did it, or orthogenesis or epigenesis, or any other genesis, have we not in any of these found a god equal to the occasion?
There are dozens of theories,--mutation, orthogenesis, Weismanism, Mendelianism, etc.