Cladistic Phylogenetic Analysis is Circular Reasoning Based on Personal Bias.

I did not realize it at the time but this was the first nail that I hammered into the lid of the coffin of my academic career. 25 years ago I was an eager Ph.D. candidate at The University of North Carolina at Chapel Hill, taking a class in Phylogenetic Systematics at Duke University under Brent D. Mishler and John G. Lundurg. I inadvertently showed that cladistic phylogenetic analysis is circular reasoning based upon personal bias.

Abstract

Archaeopteris is now known as a whole plant (Beck, 1960) that is characterized by having gymnospermous secondary wood (pycnoxylic) and pteridophytic (free sporing) reproduction. These characteristics also serve to delimit the progymnospermopsida, a lineage arising from Trimerophyte ancestors before the mid-Devonian, and extending Into the early Carboniferous. The progymnosperms as a whole are regarded as the ancestors of all gymnosperms, the Aneurophytales possibly giving rise to the Pteridospermales and Glossopteridales, and the Archaeopteridales to the Coniferales.

Considerable variation exists within the genus Archaeopteris, in terms of both reproductive and sterile appendage morphology, which has caused Beck (1961) to suggest that the variation may represent more than one genus, and possibly several. However, no estimate is currently available that adequately assesses the interspecific, and intraspecific variation, not to mention the variation that may exist within a single individual.

*** Read more ***