Replies

Genetics has occasionally led to rearrangements of the morphological tree, but I can't think of an obvious contradiction. Care to cite one

From what I've read the contortions of the geneolical tree are at a very basic, fundamental level...

As Doolittle indicates, from the base of the tree of life, it is not "tree-like." In the "bush" below (Figure 3), it is impossible to reconstruct such trees, as the observed distribution of characters create something which looks more like a tangled thicket or a bush. The three major "domains" of life--Bacteria, Archaea, and Eukarya have a distribution of characteristics which does not allow a tree to be constructed to describe their alleged ancestral relationships. This is due to a character distribution which is not what one would predict if they inherited their genes through common ancestry

The father of molecular systematics Carl Woese found that conflicts in phylogenies are present not only at the base of the tree, saying, "[p]hylogenetic incongruities [conflicts] can be seen everywhere in the universal tree, form its root to the major branchings within and among the various taxa to the makeup of the primary groupings themselves."21 For example, de Jong noted that,"the wealth of competing morphological, as well as molecular proposals [of] the prevailing phylogenies of the mammalian orders would reduce [the mammalian tree] to an unresolved bush, the only consistent clade probably being the grouping of elephants and sea cows.12". Cao et al. found that molecular-based phylogenies conflicted sharply with previously established phylogenies of major mammal groups, such as ferungulates, rhodents, and primates22.

Some studies have tried to analyze the general relationships between animals and vertebrate groups through molecular data. One study analyzed molecular data from 10 different vertebrates and found that using different mitochondrial genes, twenty different disagreeing phylogenetic trees were produced, which differed at both recent and ancient divergence points23. Brown and Naylor24 found that trees based off of entire mitochondrial DNA genomes for 19 multicellular (metazoan) organsism did not match the previously accepted phylogeny for chordates, or within chordates, for vertebrates. Finally, a study which compared many proteines in humans, nematodes, arthropods, and yeast found that 2 starkly different trees were produced, depending on which genes were used25. This pattern of different genes yielding very different phylogenetic trees is very common in the scientific literature, and shows that molecular data fail to give a consistent picture of the alleged common descent ancestry of organisms.

but I can't think of an obvious contradiction [between genetic and morphologically derived evolutionary "trees"]. Care to cite one?

Well, Galatians513 wasn't entirely clear, simply referring to "contradictory" morphological and genetic "trees". I've clarified in the angle brackets above, but a couple things might be meant. For instance one might also refer to what might be called "typological" classifications of organisms. These would group organisms according to "type," without regard to evolutionary relationships. Contrasting would be "evolutionary" classifications, which group organisms according to the inferred typology of evolutionary relationships.

Conventional taxonomy tends to conform to patterns of evolutionary relationships, just because it was originally oriented (under the guidance of Linneaus in the 17th Century) to the pattern of "groups within groups" that is a relect of evolution. Of course a creationist might argue that God simply decided to create according to a pattern of groups within groups.

Therefore the most interesting cases are those were "typological" and "evolutionary" classifications do NOT agree. In these instances creationists would expect new lines of comparative data (discovered subsequent to the gross morphological criteria on which classifications were initially based) should conform with typological rather than evolutionary schemes. Evolutionists would expect the opposite.

A couple concrete instances come to mind. (I'm sure that many more would occur to a trained biologist.) For instance (as I mentioned in another context recently) even though crocodiles are classified as "reptiles" along with snakes and lizards, they actually share a more recent common ancestor with birds. This kind of situation can arise whenever a particular lineages "diverges" sufficiently in a particular direction -- as birds did in adapting to their peculiar form of locomotion -- that we decide it should have a new name.

Not surprisingly (to the evolutionists) the proteins and DNA of crocodiles are more similar to those of birds than they are to those of snakes or lizards.

Another example concerns humans. Genetically, chimpanzees are actually more similar to humans than they are to their fellow pongids (great apes) gorillas.

In these crucial cases, the evidence conforms with common ancestry rather than typology, contrary to what would be expected if God created "types within types" (by non-evolutionary means).