Talk:Polyphyly

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This is a nice image, but I don't think it actually describes a polyphyletic group. The common ancestor of amphibians and mammals was a land vertebrate, and although the illustration does not show this, the lower land vertebrates are usually meant to include it. As such, this is a paraphyletic group, comprising all its descendants except the mammals (and I would think the birds). Might a better illustration might be the warm-blooded animals, highlighting Mammalia and Aves separately? Josh

Well, are you sure that the warm-blooded animals are a polyphyletic group? Was the most recent common ancestor of birds and mammals warm-blooded or cold-blooded? I think this picture actually shows a paraphyletic group, doesn't it? Because the yellow curve includes the fork between Mammaila and Aves? I don't know, I'm no biologist. Keenan Pepper 19:50, 21 July 2005 (UTC)

I'm not sure what to make of that picture. It's generally understood that the ancestral amniotes were cold-blooded, and crocodylians are too. Also, although it technically falls under the definition we give for paraphyletic, that group would still be polyphyletic since it leaves out connecting forms - the difference is whether the tree is topologically connected. I'm not entirely sure how to word this. Josh

How about this text? A picture highlighting mammals and birds separately would go great with it. Keenan Pepper 23:12, 22 July 2005 (UTC)

That sounds fair. The image would be easy to adapt, but it's on the commons and I don't know where the update should go. Josh

New image, based on the discussion here. There is also an svg source for the image on commons, so it should be very easy to correct. Zeimusu | Talk page 15:40, 30 September 2005 (UTC)

[edit] Examples of Polyphyly

These examples aren't clear to me. The definition of polyphyly here requires not including the common ancestor, but these examples don't state whether the nearest common ancestor is a member of the group or not. Rather, these examples say that the descendants of the common ancestor are not all included. Isn't that just paraphyly? Octavo (talk) 20:10, 26 November 2007 (UTC)

Yeah, it sure seems that way. Let me think about that. — the Sidhekin (talk) 17:11, 6 February 2008 (UTC) Meanwhile ...

Last example is misleading... seems to imply that primates are the descendants of birds and bats. This is not true - the MRCA was a non-flying reptile of some sort. 75.110.136.111 (talk) 16:18, 6 February 2008 (UTC)

Seems to me it's saying birds and bats are descended from primates ... but then, the second example seems to say plants and bacteria are descended from animals. Seems a few "descendents of" have gone missing ... hang on ... fixing ... better now?

Of course Octavo's objection still stands. — the Sidhekin (talk) 17:11, 6 February 2008 (UTC)