Meaning of orthogenesis


Pronunciation: (ôr"thu-jen'u-sis), [key]
— n.
    1. Also calledorthoselection.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.
  1. a hypothetical parallelism between the stages through which every culture necessarily passes, in spite of secondary conditioning factors.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.