In biology, homoplasy is the existence of similar characters (morphological, genetic) in different taxa without direct shared ancestry. A homoplasy, or homoplastic character state, is therefore a trait possessed / displayed by two or more taxa because of the occurrence of three phenomena: convergence, parallelism, or reversion.[2]
Homoplasy is opposed to homology.
Homoplastic character states require extra steps to explain their distribution on a most parsimonious cladogram. Homoplasy is only recognizable when other characters imply an alternative hypothesis of grouping, because in the absence of such evidence, shared features are always interpreted as similarity due to common descent.[3]
Caption — Four cladograms showing the terminology used to describe different patterns of ancestral and derived character states. Note that in this example the branching pattern is assumed to be "true" (based on other evidence).[1]
See also
edit- Morphology (biology)
- Analogy & "analogous dna sequences" : https://books.google.fr/books?id=Ofw5w1yuD8kC&pg=PA527
References
edit- Page, Roderic D.M. and Holmes, Edward C. Molecular evolution: a phylogenetic approach. Wiley-Blackwell, 1st edition, 1998.
- Régis Chirat, Derek E. Moulton and Alain Goriely. Mechanical basis of morphogenesis and convergent evolution of spiny seashells. PNAS 2013 April, 110 (15) 6015-6020. https://doi.org/10.1073/pnas.1220443110.
- Hennig, W., Phylogenetic Systematics. University of Illinois Press, Urbana IL, 1966.
Categories :Evolutionary biology terminology