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By comparison, the term paraphyly, or paraphyletic, uses the ancient Greek prefix παρά (pará), meaning "beside, near", [4] [5] and refers to the situation in which one or several monophyletic subgroups are left apart from all other descendants of a unique common ancestor. That is, a paraphyletic group is nearly monophyletic, hence the ...
The term paraphyly, or paraphyletic, derives from the two Ancient Greek words παρά (pará), meaning "beside, near", and φῦλον (phûlon), meaning "genus, species", [2] [3] and refers to the situation in which one or several monophyletic subgroups of organisms (e.g., genera, species) are left apart from all other descendants of a unique common ancestor.
In biological phylogenetics, a clade (from Ancient Greek κλάδος (kládos) 'branch'), also known as a monophyletic group or natural group, [1] is a grouping of organisms that are monophyletic – that is, composed of a common ancestor and all its lineal descendants – on a phylogenetic tree. [2]
Cladogram (family tree) of a biological group. The green box (central) may represent an evolutionary grade (paraphyletic), a group united by conservative anatomical and physiological traits rather than phylogeny. The flanking red and blue boxes are clades (i.e., complete monophyletic subtrees).
While paraphyletic assemblages are popular among paleontologists and evolutionary taxonomists, cladists do not recognize paraphyletic assemblages as having any formal information content – they are merely parts of clades. Polyphyly: A polyphyletic assemblage is one which is neither monophyletic nor paraphyletic.
Again, while not disagreeing with the notion that only monophyletic groups should be named, empiricist systematists counter this ancestry essentialism by pointing out that pelycosaurs are recognized as paraphyletic precisely because they exhibit a combination of synapomorphies and symplesiomorphies indicating that some of them are more closely ...
In taxonomy, a group is paraphyletic if it consists of the group's last common ancestor and all descendants of that ancestor excluding one or more subgroups. See also the categories Polyphyletic groups and Obsolete taxa
Phylogenetic groups: A monophyletic taxon (in yellow, the clade Sauropsida grouping "reptiles and birds") contains a common ancestor and all of its descendants. A paraphyletic taxon (in cyan, the "reptiles") contains its most recent common ancestor, but does not contain all the descendants of that ancestor.