Free Republic
Browse · Search
News/Activism
Topics · Post Article

To: allmendream
Actually classifying animals phylogenetic relationship based upon genetic homology is ‘easy’, ‘simple’ and ‘clear’; and it confirms the Linnean classification system based upon morphology in most cases.

A facile assurance that requires for its acceptance the ability to completely ignore the long, raging conflict in systematics between molecular and morphological phylogenies.

“No consistent organismal phylogeny has emerged from the many individual protein phylogenies so far produced. Phylogenetic incongruities can be seen everywhere in the universal tree, from its root to the major branchings within and among the various taxa to the makeup of the primary groupings themselves.”
Woese, Carl. 1998. The Universal Ancestor. Proceedings of the National Academy of Sciences USA 95:6854-6859.

A"s morphologists with high hopes of molecular systematics, we end this survey with our hopes dampened. Congruence between molecular phylogenies is as elusive as it is in morphology and as it is between molecules and morphology. . . . Partly because of morphology’s long history, congruence between morphological phylogenies is the exception rather than the rule. With molecular phylogenies, all generated within the last couple of decades, the situation is little better. Many cases of incongruence between molecular phylogenies are documented above; and when a consensus of all trees within 1% of the shortest in a parsimony analysis is published (e.g. 132, 152, 170), structure or resolution tends to evaporate."
Patterson, Colin, and others. 1993. Congruence Between Molecular and Morphological Phylogenies. Annual Review of Ecology and Systematics 24:153-188.

Cordially,

73 posted on 09/21/2007 12:02:44 PM PDT by Diamond
[ Post Reply | Private Reply | To 71 | View Replies ]


To: Diamond
Woese’s paper is on the search for the universal common ancestor, not a simple phylogenetic analysis of two species.

Moore and Wilner also conclude that...

“Complementary use of molecular characters shows promise”

and that...

“combination of morphological and molecular methods has made much progress.”

It has made even more progress in the decade since 1995 when the authors made that statement.

Please refer to this and THOUSANDS of other studies done since 1995 that use this graceful, easy, clear and simple method ...

Ray DA, Xing J, Hedges DJ, Hall MA, Laborde ME, Anders BA, White BR, Stoilova N, Fowlkes JD, Landry KE, Chemnick LG, Ryder OA, Batzer MA.
Department of Biological Sciences, Biological Computation and Visualization Center, Center for Bio-Modular Multi-scale systems, Louisiana State University, 202 Life Sciences Bldg., Baton Rouge, LA 70803, USA.

Short INterspersed Elements (SINEs) make very useful phylogenetic markers because the integration of a particular element at a location in the genome is irreversible and of known polarity. These attributes make analysis of SINEs as phylogenetic characters an essentially homoplasy-free affair. Alu elements are primate-specific SINEs that make up a large portion of the human genome and are also widespread in other primates. Using a combination wet-bench and computational approach we recovered 190 Alu insertions, 183 of which are specific to the genomes of nine New World primates. We used these loci to investigate branching order and have produced a cladogram that supports a sister relationship between Atelidae (spider, woolly, and howler monkeys) and Cebidae (marmosets, tamarins, and owl monkeys) and then the joining of this two family clade to Pitheciidae (titi and saki monkeys). The data support these relationships with a homoplasy index of 0.00. In this study, we report one of the largest applications of SINE elements to phylogenetic analysis to date, and the results provide a robust molecular phylogeny for platyrrhine primates.

PMID: 15737586 [PubMed - indexed for MEDLINE]

74 posted on 09/21/2007 4:14:26 PM PDT by allmendream (A Lyger is pretty much my favorite animal. (Hunter08))
[ Post Reply | Private Reply | To 73 | View Replies ]

Free Republic
Browse · Search
News/Activism
Topics · Post Article


FreeRepublic, LLC, PO BOX 9771, FRESNO, CA 93794
FreeRepublic.com is powered by software copyright 2000-2008 John Robinson