Thursday, September 10, 2015

Early Homo in South Africa

The New York Times is reporting on a new find out of South Africa, by Lee Berger and his team, that indicates the presence of early Homo there.  John Noble Wilford writes:
The new hominin species was announced on Thursday by an international team of more than 60 scientists led by Lee R. Berger, an American paleoanthropologist who is a professor of human evolution studies at the University of the Witwatersrand in Johannesburg. The species name, H. naledi, refers to the cave where the bones lay undisturbed for so long; “naledi” means “star” in the local Sesotho language.

In two papers published this week in the open-access journal
eLife, the researchers said that the more than 1,550 fossil elements documenting the discovery constituted the largest sample for any hominin species in a single African site, and one of the largest anywhere in the world. Further, the scientists said, that sample is probably a small fraction of the fossils yet to be recovered from the chamber. So far the team has recovered parts of at least 15 individuals.

“With almost every bone in the body represented multiple times, Homo naledi is already practically the best-known fossil member of our lineage,” Dr. Berger said.
Here is the link to the first paper, Homo naledi, a new species of the genus Homo from the Dinaledi Chamber, South Africa, and here is the link to the taphonomic paper, Geological and taphonomic context for the new hominin species Homo naledi from the Dinaledi Chamber, South Africa. Here is the picture from the main paper, as well as the abstract:
Homo naledi is a previously-unknown species of extinct hominin discovered within the Dinaledi Chamber of the Rising Star cave system, Cradle of Humankind, South Africa. This species is characterized by body mass and stature similar to small-bodied human populations but a small endocranial volume similar to australopiths. Cranial morphology of H. naledi is unique, but most similar to early Homo species including Homo erectus, Homo habilis or Homo rudolfensis. While primitive, the dentition is generally small and simple in occlusal morphology. H. naledi has humanlike manipulatory adaptations of the hand and wrist. It also exhibits a humanlike foot and lower limb. These humanlike aspects are contrasted in the postcrania with a more primitive or australopith-like trunk, shoulder, pelvis and proximal femur. Representing at least 15 individuals with most skeletal elements repeated multiple times, this is the largest assemblage of a single species of hominins yet discovered in Africa.


What does this mean?  Well, the principle problem is that we still have no date for these remains, so it is difficult to place them chronologically.  Berger is standing by his contention that early Homo arose from something like Au sediba, despite evidence to the contrary recently uncovered in Northeast Africa.  If the date is late, somewhere on the order of one million years, then a migration model might explain the appearance of such an advanced hominin in this area.  If it turns out to be much older, then other models might have to be entertained.  More thoughts on this find later.

5 comments:

  1. Anonymous1:17 PM

    Isn't is possible that 'Homo naledi' is just another dead-end ape line that has nothing to do with the human lineage?

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    Replies
    1. The problem with this perspective is that it has few to no ape characteristics. That is what puts it in the Homo line. It is very distinguishable from apes, and there are no ape fossils in South Africa, in any event.

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  2. Yes, there are some uncertainties attaching to the details of this find:
    http://forums.bcseweb.org.uk/viewtopic.php?f=9&t=3703
    (P Z Myers and Aron Ra have highlighted these in blogs.)

    But the responses of YECs and other anti-evolutionists should make for interesting reading.

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  3. Actually, there are many uncertainties as there always are with these frequent 'missing link' announcements.

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  4. Are those bones even from the same creature or a match up to suit their discovery?

    Was it an awesome dwelling down by a waterfall with plenty of food and a nice temperature that many animals may have sheltered in for 1000's of years?

    ReplyDelete