Homoplasy: Difference between revisions

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'''Homoplasy''' is a term used in [[biology]] and [[genetics]] to describe a trait shared by two or more species that is not due to common ancestry. Instead, it is the result of similar environmental pressures leading to similar adaptations, a process known as [[convergent evolution]], or due to [[genetic drift]].
{{Short description|An overview of homoplasy in evolutionary biology}}


==Definition==
==Homoplasy==
Homoplasy is derived from the Greek words ''homo'' meaning same and ''plasis'' meaning form. In the context of [[evolutionary biology]], it refers to the independent evolution of similar traits in different species or lineages. This is in contrast to [[homology (biology)|homology]], where shared traits are due to common ancestry.
[[File:Apomorphy_-_Homoplasy.svg|thumb|right|Diagram illustrating homoplasy and apomorphy]]
'''Homoplasy''' refers to a phenomenon in evolutionary biology where a trait has evolved independently in different species, not due to shared ancestry but rather as a result of convergent evolution, parallel evolution, or evolutionary reversals. This can lead to similarities in traits among species that do not share a recent common ancestor.


==Types of Homoplasy==
==Types of Homoplasy==
There are three main types of homoplasy: [[convergent evolution]], [[parallel evolution]], and [[reversal evolution]].
Homoplasy can occur through several mechanisms:


===Convergent Evolution===
===Convergent Evolution===
Convergent evolution occurs when different species independently evolve similar traits due to similar environmental pressures. An example of this is the evolution of wings in both birds and bats.
Convergent evolution occurs when different species evolve similar traits independently, often because they have adapted to similar environments or ecological niches. An example of convergent evolution is the development of wings in bats and birds.


===Parallel Evolution===
===Parallel Evolution===
Parallel evolution occurs when two related species independently evolve similar traits after their divergence from a common ancestor. An example of this is the evolution of similar body shapes in dolphins and ichthyosaurs.
Parallel evolution happens when two related species evolve in similar ways for a long period of time in response to similar environmental pressures. An example is the similar development of resistance to a particular pesticide in different populations of insects.


===Reversal Evolution===
===Evolutionary Reversals===
Reversal evolution, or evolutionary reversal, occurs when a species re-evolves a trait that its ancestors had lost. An example of this is the re-evolution of teeth in some species of frogs.
Evolutionary reversals occur when a species reverts to a trait that was present in an ancestor but was lost in intermediate generations. This can result in a trait appearing to be similar in two species, even though it was not present in their most recent common ancestor.


==Implications for Phylogenetics==
==Distinguishing Homoplasy from Homology==
Homoplasy can complicate the reconstruction of [[phylogenetic trees]], as it can lead to the incorrect inference of relationships based on shared traits. Methods such as [[maximum parsimony (phylogenetics)|maximum parsimony]] and [[maximum likelihood]] are used to minimize the impact of homoplasy on phylogenetic analyses.
Homoplasy is often contrasted with [[homology]], which refers to traits inherited by two different species from a common ancestor. While homology indicates a shared evolutionary history, homoplasy indicates independent evolutionary paths.


==See Also==
==Significance in Phylogenetics==
* [[Analogy (biology)]]
In [[phylogenetics]], homoplasy can complicate the reconstruction of evolutionary relationships because it can lead to the incorrect assumption that species with similar traits are closely related. Phylogeneticists must carefully analyze traits to determine whether they are homologous or homoplastic.
 
==Related pages==
* [[Convergent evolution]]
* [[Parallel evolution]]
* [[Evolutionary biology]]
* [[Evolutionary biology]]
* [[Phylogenetics]]
* [[Phylogenetics]]
* [[Homology (biology)]]


[[Category:Biology]]
[[Category:Genetics]]
[[Category:Evolutionary biology]]
[[Category:Evolutionary biology]]
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Latest revision as of 12:09, 15 February 2025

An overview of homoplasy in evolutionary biology


Homoplasy[edit]

Diagram illustrating homoplasy and apomorphy

Homoplasy refers to a phenomenon in evolutionary biology where a trait has evolved independently in different species, not due to shared ancestry but rather as a result of convergent evolution, parallel evolution, or evolutionary reversals. This can lead to similarities in traits among species that do not share a recent common ancestor.

Types of Homoplasy[edit]

Homoplasy can occur through several mechanisms:

Convergent Evolution[edit]

Convergent evolution occurs when different species evolve similar traits independently, often because they have adapted to similar environments or ecological niches. An example of convergent evolution is the development of wings in bats and birds.

Parallel Evolution[edit]

Parallel evolution happens when two related species evolve in similar ways for a long period of time in response to similar environmental pressures. An example is the similar development of resistance to a particular pesticide in different populations of insects.

Evolutionary Reversals[edit]

Evolutionary reversals occur when a species reverts to a trait that was present in an ancestor but was lost in intermediate generations. This can result in a trait appearing to be similar in two species, even though it was not present in their most recent common ancestor.

Distinguishing Homoplasy from Homology[edit]

Homoplasy is often contrasted with homology, which refers to traits inherited by two different species from a common ancestor. While homology indicates a shared evolutionary history, homoplasy indicates independent evolutionary paths.

Significance in Phylogenetics[edit]

In phylogenetics, homoplasy can complicate the reconstruction of evolutionary relationships because it can lead to the incorrect assumption that species with similar traits are closely related. Phylogeneticists must carefully analyze traits to determine whether they are homologous or homoplastic.

Related pages[edit]