controversial fossil hominin relationships.
Mana Dembo, Nicholas J. Matzke, Arne O. Mooers, Mark Collard.
The phylogenetic relationships of several hominin species remain
controversial. Two methodological issues contribute to the
uncertainty—use of partial, inconsistent datasets and reliance on
phylogenetic methods that are ill-suited to testing competing
hypotheses. Here, we report a study designed to overcome these issues.
We first compiled a supermatrix of craniodental characters for all
widely accepted hominin species. We then took advantage of recently
developed Bayesian methods for building trees of serially sampled tips
to test among hypotheses that have been put forward in three of the
most important current debates in hominin phylogenetics—the
relationship between Australopithecus sediba and Homo, the taxonomic
status of the Dmanisi hominins, and the place of the so-called hobbit
fossils from Flores, Indonesia, in the hominin tree. Based on our
results, several published hypotheses can be statistically rejected.
For example, the data do not support the claim that Dmanisi hominins
and all other early Homo specimens represent a single species, nor
that the hobbit fossils are the remains of small-bodied modern humans,
one of whom had Down syndrome. More broadly, our study provides a new
baseline dataset for future work on hominin phylogeny and illustrates
the promise of Bayesian approaches for understanding hominin
Also, Australopithecus sediba "groups with Homo and may be its
ancestor" (but implying a stratigraphic gap of 300.000-800.000 years),
and Sahelanthropus is the most basal hominin, followed by Ardipithecus
(Orrorin was not included in this study).