orthogenesis

American  

[awr-thuh-jen-uh-sis] / ˌɔr θəˈdʒɛn ə sɪs /

noun

1. Biology.

   1. Also called orthoselection.  evolution of a species proceeding by continuous structural changes in a single lineage without presenting a branching pattern of descent.

   2. a theory that the evolution of a species in a continuous, nonbranching manner is due to a predetermined series of alterations intrinsic to the species and not subject to natural selection.

2. Sociology. a hypothetical parallelism between the stages through which every culture necessarily passes, in spite of secondary conditioning factors.

---

orthogenesis British  

/ ˌɔːθəʊˈdʒɛnɪsɪs, ˌɔːθəʊdʒɪˈnɛtɪk /

noun

1. biology

   1. evolution of a group of organisms predetermined to occur in a particular direction

   2. the theory that proposes such a development

2. the theory that there is a series of stages through which all cultures pass in the same order

---

Other Word Forms

• orthogenetic
  adjective
• orthogenetically
  adverb

Etymology

Origin of orthogenesis

From New Latin, dating back to 1890–95; see origin at ortho-, genesis

Example Sentences

See Examples For:

orthogenesis

The various models proposed for the mechanism of evolution, such as Lamarckian evolution, orthogenesis, and use-disuse, all implied some level of teleology, that there was a directionality inherent in the process.

From Scientific American ● Sep. 5, 2021

There are dozens of theories,—mutation, orthogenesis, Weismanism, Mendelianism, etc.,— and each has its adherents,—but they agree in one thing, that "Natural Selection" does not account for the forms of life on earth to-day.

From Evolution An Investigation and a Critique by Graebner, Theodore

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?

From The Last Harvest by Burroughs, John

In consequence of an interruption of orthogenesis a stoppage ensues in certain stages of the development, and this stoppage is the great cause of the arrangement of forms in different species.

From At the Deathbed of Darwinism A Series of Papers by O'Harra, Edwin V.

We should thus arrive at a demonstration of what Eimer called orthogenesis, or evolution in definite directions.

From Hormones and Heredity by Cunningham, J. T.