[Taxacom] Which Australopithecus species (garhi or africanus) is closest sister group to genus Homo

[Kenneth Kinman]

Hi all,
         I have decided that Australopithecus sediba probably clades with A. africanus (together forming the sister group to Homo), rather than A. sediba being the sole sister group to Homo.  More specimens are needed.    The placement of A. platyops (originally placed in a separate genus) is still very problematic due to distortion of the skull.   My revised classification is given below.
                             ------------------Ken

Australopithecus%
1  A. anamensis
2  A. afarensis
?  A. platyops
3  A. aethiopicus
B  A. robustus robustus
C  A. robustus boisei
4  A. garhi
5  A. africanus
B  A. sediba
6  {{Homo}}

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From: Taxacom <taxacom-bounces at mailman.nhm.ku.edu> on behalf of Kenneth Kinman via Taxacom <taxacom at mailman.nhm.ku.edu>
Sent: Monday, February 17, 2020 8:35 PM
To: taxacom at mailman.nhm.ku.edu <taxacom at mailman.nhm.ku.edu>
Subject: Re: [Taxacom] Which Australopithecus species (garhi or africanus) is closest sister group to genus Homo

Followup:
       I found the Introduction article to a 2018 special issue on Australopithecus sediba.  It indicates that it uncertain whether the features that A. sediba shares with genus Homo are synapomorphies (showing that they form a clade that excludes A. africanus) or if those features are convergent.  If convergent, that would presumably mean that A. sebida instead clades with A. africanus, and that together they are the sister group of genus Homo (rather than only A. sediba being the sister group to Homo).
                                  -------------Ken

http://www.paleoanthro.org/media/journal/content/PA20180049.pdf


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From: Taxacom <taxacom-bounces at mailman.nhm.ku.edu> on behalf of Kenneth Kinman via Taxacom <taxacom at mailman.nhm.ku.edu>
Sent: Monday, February 17, 2020 6:52 PM
To: taxacom at mailman.nhm.ku.edu <taxacom at mailman.nhm.ku.edu>
Subject: [Taxacom] Which Australopithecus species (garhi or africanus) is closest sister group to genus Homo

Hi all,
      I was rereading a 2015 paper on the oldest known fossil (mandible and teeth) of the genus Homo dated at about 2.75 million years in age.  It seems to argue against Australopithecus garhi being the closest sister species to genus Homo, and provides some evidence that A. africanus is perhaps instead the nearest sister group to Homo (and A. garhi splitting off before an A. africanus-Homo clade).  Are there any papers since 2015 which dispute this?
      Since there are remains of Australopithecus africanus that are both older and younger than 2.75 million years, I suppose that one could hypothesize that an unknown population of A. africanus actually gave rise to genus Homo, thus making Australopithecus africanus a paraphyletic "ancestral" species.
                                     ---------------Ken

https://science.sciencemag.org/content/347/6228/1352.full
[https://science.sciencemag.org/sites/default/files/highwire/sci/347/6228.cover-source.gif]<https://science.sciencemag.org/content/347/6228/1352.full>
Early Homo at 2.8 Ma from Ledi-Geraru, Afar, Ethiopia | Science<https://science.sciencemag.org/content/347/6228/1352.full>
The fossil record of humans is notoriously patchy and incomplete. Even so, skeletal remains and artifacts unearthed in Africa in recent decades have done much to illuminate human evolution. But what is the origin of the genus Homo ? Villmoare et al. found a fossil mandible and teeth from the Afar region in Ethiopia. The find extends the record of recognizable Homo by at least half a million ...
science.sciencemag.org

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