Talk:Monophyletic
From Academic Kids
- In fact, biologists are discussing this issue with regards to the genus Homo at this very moment, though for different reasons. For example, H. heidelbergensis and H. neanderthalensis are thought to be subspecies of H. sapiens. Therefore, Homo is not strictly monophyletic!
That's wrong. If H. heidelbergensis and H. neanderthalensis were subspecies of H.sapiens, then they would by definition HAVE common ancestral form, and that wouldn't interfere with monophylecity of Homo in any way. --Taw
One way or the other, folks, Homo is not a good example. More enlightening quibbles are found in the Dinosauria/Aves cladistics, no?
This entry must mention cladistics/clades to be intelligible. User:Wetman
definition of polyphyletic as distinct from paraphyletic
The definition of polypheltic, as distinct from paraphyletic, doesn't make sense to me. Could someone help clear up the following points and/or update the article.
- In phylogenetics, a group is monophyletic (greek: of one stem) if all organisms in that group are known to have developed from a common ancestral form, and all descendants of that form are included in the group.
How is possible for the organisms in the group to not have a common ancestral form? If the evolutionary tree really is a tree then this will always be the case, and removing this condition would make no difference to the definition.
- Taxonomic groups that contain organisms but not their common ancestor are called polyphyletic, and groups that contain some but not all descendants of a given form are called paraphyletic.
Every subset of the set of extant species will always have a latest common ancestor, so what does it mean for a taxonomic group to contain organisms but not their common ancestor?
The difference is whether the last common ancestor is in the group. For instance warm-blooded vertebrates all evolved from the ancestral reptile, but it wasn't itself warm-blooded, so they form a polyphyletic group.
Move to monophyly?
Should this article not be moved to 'monophyly'? Should articles not preferably have a noun as the subject instead of an adjective? Fedor 08:19, 31 Aug 2004 (UTC)
