How Reliable Are Human
Phylogenetic Hypotheses?
Posted: October 6, 2005
"The upsurge in paleoanthropological field research over the past quarter century has resulted in the recognition of many new hominin species, including Australopithecus afarensis (1), Paranthropus aethiopicus (2), Ardipithecus ramidus (3, 4), Australopithecus anamensis (5), Australopithecus bahrelghazali (6), Homo antecessor (7), and Australopithecus garhi (8). This has led to commensurate interest in the generation of reliable hypotheses about human phylogeny (8-14). Without a reliable phylogeny, little confidence can be placed in hypotheses of ancestry, or in scenarios linking events in human evolution with environmental and ecological influences. However, the phylogenetic relationships of the dozen, or so, species whose remains comprise the hominin fossil record are far from certain. Despite, in paleontological terms, a relative abundance of fossil evidence, cladistic analyses of the hominins have so far yielded conflicting and weakly supported hypotheses of relationships (9-14, 15, 16). Conventionally, this state of affairs has been attributed to poor character choice, taxonomic disagreements, or flaws in the available analytical methods (10, 12, 14). A fourth possibility, namely, that the type of qualitative and quantitative craniodental characters normally used to reconstruct the phylogenetic relationships of hominin species and genera are not reliable for this purpose, has only recently been entertained (8, 13, 17-21)."
"Vol. 97, Issue 9, 5003-5006, April 25, 2000
Anthropology
How reliable are human phylogenetic hypotheses?
Mark Collard*, and Bernard Wood
* Department of Anthropology, University College London, London WC1E 6BT, United Kingdom; and Department of Anthropology, George Washington University, Washington, DC 20052
Communicated by David Pilbeam, Harvard University, Cambridge, MA, January 28, 2000 (received for review May 27, 1999)
Cladistic analysis of cranial and dental evidence has been widely used to generate phylogenetic hypotheses about humans and their fossil relatives. However, the reliability of these hypotheses has never been subjected to external validation. To rectify this, we applied identical methods to equivalent evidence from two groups of extant higher primates for whom reliable molecular phylogenies are available, the hominoids and papionins. We found that the phylogenetic hypotheses based on the craniodental data were incompatible with the molecular phylogenies for the groups. Given the robustness of the molecular phylogenies, these results indicate that little confidence can be placed in phylogenies generated solely from higher primate craniodental evidence. The corollary of this is that existing phylogenetic hypotheses about human evolution are unlikely to be reliable. Accordingly, new approaches are required to address the problem of hominin phylogeny."
The entire paper can be found online here.