Editing Paraphyly (section)

=== Uses for paraphyletic groups ===

{{anchor|Cladistics generally discourages paraphyletic groups}}

When the appearance of significant traits has led a subclade on an evolutionary path very divergent from that of a more inclusive clade, it often makes sense to study the paraphyletic group that remains without considering the larger clade. For example, the [[Neogene]] evolution of the [[Even-toed ungulate|Artiodactyla]] (even-toed ungulates, like deer, cows, pigs and hippopotamuses - [[Cervidae]], [[Bovidae]], [[Suidae]] and [[Hippopotamidae]], the families that contain these various artiodactyls, are all monophyletic groups) has taken place in environments so different from that of the [[Cetacea]] (whales, dolphins, and porpoises) that the Artiodactyla are often studied in isolation even though the cetaceans are a descendant group. The [[prokaryote]] group is another example; it is paraphyletic because it is composed of two Domains (Eubacteria and Archaea) and excludes (the [[eukaryotes]]). It is very useful because it has a clearly defined and significant distinction (absence of a cell nucleus, a [[plesiomorphy]]) from its excluded descendants.{{citation needed|date=October 2020}}

Also, some systematists recognize paraphyletic groups as being involved in evolutionary transitions, the development of the first tetrapods from their ancestors for example. Any name given to these hypothetical ancestors to distinguish them from tetrapods—"fish", for example—necessarily picks out a paraphyletic group, because the descendant tetrapods are not included.<ref>{{cite web|author1=Kazlev, M.A.  |author2=White, T. |name-list-style=amp |title=Amphibians, Systematics, and Cladistics |url=http://palaeos.com/vertebrates/tetrapoda/amphibians.html |publisher=[[Palaeos]] website |access-date=16 August 2012}}</ref> Other systematists consider reification of paraphyletic groups to obscure inferred patterns of evolutionary history.<ref>{{cite journal |last=Patterson |first=Colin |title=Morphology and interrelationships of primitive actinopterygian fishes |journal=American Zoologist |volume=22 |issue=2 |year=1982 |pages=241–259|doi=10.1093/icb/22.2.241 |doi-access=free }}</ref>

The term "[[evolutionary grade]]" is sometimes used for paraphyletic groups.<ref name="Ancestors_Tale">{{Cite book | first=Richard | last=Dawkins | author-link=Richard Dawkins | title=The Ancestor's Tale, A Pilgrimage to the Dawn of Life | chapter=Mammal-like Reptiles | publisher=Houghton Mifflin | location=Boston| year=2004| isbn=978-0-618-00583-3 | title-link=The Ancestor's Tale }}</ref>
Moreover, the concepts of [[monophyly]], paraphyly, and [[polyphyly]] have been used in deducing key genes for [[DNA barcoding|barcoding]] of diverse group of species.<ref>{{cite journal |doi=10.1016/j.gene.2019.143967 |pmid=31279710 |title=Diagnosis of mitogenome for robust phylogeny: A case of Cypriniformes fish group |journal=Gene |volume=713 |pages=143967 |year=2019 |last1=Parhi |first1=J. |author2=Tripathy, P.S. |author3=Priyadarshi, H. |author4=Mandal S.C. |author5=Pandey P.K. |s2cid=195828782 }}</ref>