USING MOLECULAR DATA AND COMPUTERS IN SYSTEMATICS: WHAT THE TORTOISE GEOCHELONE TAUGHT US

There has been a recent trend towards increased use of molecular data and computers in systematics and taxonomy. These methods allow scientists to build phylogenies without knowledge of the organisms that they are studying. Scientists who make cladograms thus sometimes show great ignorance both of the fossil record and also of animal morphology, which makes their conclusions suspect. In addition, many scientists who do use morphology have been making questionable conclusions about taxonomy. In this paper, we show this trend with several examples in the literature on Geochelone (Testudinata). New molecular phylogenies make strange claims about relationships within this group. Since few scientists are now studying fossil tortoises, our knowledge of their evolutionary history is very poor and claims about their relationships based on molecular phylogenies have gone largely unchallenged. Finally, during the last twenty years there has been a trend in splitting the once-large genus Geochelone into many new genera based on morphological cladistic analyses. Not only is this disrupting traditional turtle nomenclature but it does not reflect what is known about morphological evolution of the genus Geochelone.