[Taxacom] georgicus

[Ken Kinman]

Dear All,

      A paper in this week's issue of Science describing a fifth skull of Homo erectus georgicus is causing quite a stir, not only among anthropologists, but even some of the main stream news outlets.  The authors apparently propose lumping early Homo species even more than I have.
 
       In my 2009 classification of genus Homo, posted here on Taxacom, I lumped Homo rudolfensis (as a subspecies) into Homo habilis, and Homo georgicus, ergaster and even floresiensis (as subspecies) into Homo erectus.  What is now being proposed would lump them all into just a single variable Homo erectus.  I'm not quite ready to go quite that far, but I certainly think it is about time to put an end to needless splitting of such forms into new species.  
 
     It is interesting that the cranial capacity of this male is rather low (about 550 cc).  And the estimated cranial capacity of Homo erectus floresiensis ("the Hobbitt") was raised earlier this year to about 425 cc.   Therefore, it now seems even less of a stretch for me to have theorized that Homo erectus georgicus gave rise to Homo erectus floresiensis.  When an island form shrinks in body size, its brain size would be expected to shrink somewhat as well.  I don't remember offhand, but I'm pretty sure the dwarf mammoths of Wrangel Island (and certain other islands) experienced a similar reduction in brain size (if not more).  
 
     The point is that these populations were more variable than we realized.  Whether I will continue recognizing two species of early Homo (Homo habilis and Homo erectus), or further lump them into just one even more variable species Homo erectus, I am not yet sure.  But it certainly makes me even more skeptical about any new species of Homo being described that lived between 2.0 and 1.8 million years ago (including Homo gautengensis proposed about 3 years ago).  I have no problem with them naming such populations as new subspecies.
 
                            -----------------Ken Kinman