Nested Hierarchy and Universal Common Descent- Shattering the Myth
Seeing that there was no end to this discussion I went out and did some research.
I found it strange that if UCD led to nested hierarchy it wasn't presented in any biology textbooks. So I dug a little deeper to find out why that is.
It seems the only "source" for this is Talk Origins:
As seen from the phylogeny in Figure 1, the predicted pattern of organisms at any given point in time can be described as "groups within groups", otherwise known as a nested hierarchy.-Douglas Theobald
Two things wrong with that statement:
1) A nested hierarchy is more than merely “groups within groups”.
2) The pattern represents “groups under groups” (Darwin's words). And as Darwin pointed out each horizontal line is equal to a thousand generations or more.
I request the reader to turn to the diagram illustrating the action, as formerly explained, of these several principles; and he will see that the inevitable result is, that the modified descendants proceeding from one progenitor become broken up into groups subordinate to groups.-Charles Darwin (bold added)
But with organic beings the case is different, and the view above given accords with their natural arrangement in group under group; and no other explanation has ever been attempted.-Charles Darwin (bold added)
Not “groups within groups”, as the talk-origins article states it.
So I went and re-read "On the Origins of Species". And just as I have been saying UCD does not predict a nested hierarchy:
The intervals between the horizontal lines in the diagram, may represent each a thousand or more generations.-Charles Darwin chapter 4
In chapter 14:
If, however, we suppose any descendant of A or of I to have become so much modified as to have lost all traces of its parentage in this case, its place in the natural system will be lost, as seems to have occurred with some few existing organisms.-Charles Darwin chapter 14
Extinction has only defined the groups: it has by no means made them; for if every form which has ever lived on this earth were suddenly to reappear, though it would be quite impossible to give definitions by which each group could be distinguished, still a natural classification, or at least a natural arrangement, would be possible.- Charles Darwin chapter 14
There you have it- Darwin's words refute the notion that UCD predicts a nested hierarchy and for the very reasons I have been telling Zachriel since he started spewing his nonsense.