Homology vs. Homoplasy

Homologynoun

A homologous relationship.

Homologynoun

(topology) A theory associating a system of groups to each topological space.

Homologynoun

(algebra) A certain system of groups associated to a chain complex.

Homologynoun

(chemistry) The relationship between the elements in the same group of the periodic table, or between organic compounds in a homologous series.

Homologynoun

(evolutionary theory) A correspondence of structures in two life forms with a common evolutionary origin, such as flippers and hands.

Homologynoun

(genetics) The presence of the same series of bases in related genes.

Homologynoun

The quality of being homologous; correspondence; relation; as, the homologyof similar polygons.

Homologynoun

Correspondence or relation in type of structure in contradistinction to similarity of function; as, the relation in structure between the leg and arm of a man; or that between the arm of a man, the fore leg of a horse, the wing of a bird, and the fin of a fish, all these organs being modifications of one type of structure.

Homologynoun

The correspondence or resemblance of substances belonging to the same type or series; a similarity of composition varying by a small, regular difference, and usually attended by a regular variation in physical properties; as, there is an homology between methane, CH4, ethane, C2H6, propane, C3H8, etc., all members of the paraffin series. In an extended sense, the term is applied to the relation between chemical elements of the same group; as, chlorine, bromine, and iodine are said to be in homology with each other. Cf. Heterology.

Homologynoun

the quality of being similar or corresponding in position or value or structure or function

Homoplasynoun

(evolutionary theory) A correspondence between the parts or organs of different species acquired as the result of parallel evolution or convergence.

Homoplasynoun

See Homogeny.

Homoplasy

Homoplasy, in biology and phylogenetics, is when a trait has been gained or lost independently in separate lineages over the course of evolution. This is different from homology, which is the similarity of traits can be parsimoniously explained by common ancestry.