[Taxacom] Homo floresciensis phylogeny

[John Grehan]

Some of you may be aware of the cladistic analysis of Homo floresiensis
relationships published in the Journal of Human Evolution. The authors
propose that their evidence support two equally parsimonious trees, both
of which place floresiensis as a relatively basal member of Homo (with
only H. habilis and H. rudolfensis being more basal). But the analysis
turns out to be quite problematic to say the least. At first glance it
would seem to be a thorough study with a total of 60 characters. But the
details undermine their validity. 

 

Of the 60, 17 characters have cladistically invalid character states -
i.e. the character states for the ingroup (hominids including hobbit)
are all in the outgroup. This means that the similarity between any of
the ingroup may be due to primitive retention. A further 25 characters
were uninformative (even if they are correctly documented) for the
hobbit because the hobbit character state is either in the outgroup
(most cases) and therefore not a cladistic feature, or is missing for
the hobbit, or autapomorphic for the hobbit. 

 

One character appears to be incorrectly documented or and
problematically compared (character 3). 

 

This leaves only 17 characters (less than a third of the total) that
have the appearance of conforming to cladistic requirements and
informative for similarities between the hobbit and other hominids. But
even here the comparison are marred by the lack of descriptive
documentation (actual measurements and illustrations) as well as an
outgroup being limited to the African apes.

 

 So whether the remaining 17 have any validity remains to be seen. But
at this point the description of 'cladistic' is somewhat misleading and
the result far from providing any confidence about its phylogenetic
placement.

 

John Grehan

 

 

Dr. John R. Grehan

Director of Science

Buffalo Museum of Science1020 Humboldt Parkway

Buffalo, NY 14211-1193

email: jgrehan at sciencebuff.org

Phone: (716) 896-5200 ext 372

 

Panbiogeography

http://www.sciencebuff.org/research/current-research-activities/john-gre
han/evolutionary-biography
<http://www.sciencebuff.org/biogeography_and_evolutionary_biology.php> 

Ghost moth research

http://www.sciencebuff.org/research/current-research-activities/john-gre
han/ghost-moths
<http://www.sciencebuff.org/systematics_and_evolution_of_hepialdiae.php>


Human evolution and the great apes

http://www.sciencebuff.org/research/current-research-activities/john-gre
han/human-origins