April 01, 2016

Zhiren cave human remains: 116-106 ka old

Quaternary International doi:10.1016/j.quaint.2015.12.088

The age of human remains and associated fauna from Zhiren Cave in Guangxi, southern China

Yanjun Cai et al.

Zhiren Cave in southern China is an important site for the study of the origin and the environmental background of early modern humans. The combination of Elephas kiangnanensis, Elephas maximus, and Megatapirus augustus, indicates an early representative of the typical Asian elephant fauna. Previous U-series dating of flowstone calcite has pinpointed an upper age limit for the fossils of about 100 ka. In order to achieve a better comprehension of the chronology of the modern human and contemporaneous faunal assemblage, paleomagnetic, stratigraphic, and optically stimulated luminescence (OSL) dating methods have been applied to the cave sediments. Paleomagnetic analyses reveal that there is a reversed polarity excursion below the fossiliferous layer. This excursion can be regarded as the Blake excursion event, given the U-series ages of the overlying flowstone calcite, the OSL measurements, the virtual geomagnetic pole (VGP) path of the excursion, the two reverse polarity zones within this excursion event, and the characteristic of the fauna assemblage. The human remains and mammalian fauna assemblage can be bracketed to 116–106 ka. Application of OSL dating leads to erroneous ages, largely due to the uncertainty associated with the estimation on the dose rates.

Link

9 comments:

Ronald Demos said...

Thank you for this information

redzengenoist said...

Do you think this is credible, Dienekes? 100ka would predate the human West/East lineage split, would it not?

eurologist said...

That appears to solidify the dates.

The specimen could be of a person exemplifying the admixture of AMHs with heidelbergensis ("Denisovans").

sykes.1 said...

Is there any possible connection between these remains and the long lost Pekin Man?

terryt said...

Many will find this interesting, I'm sure:

http://biorxiv.org/content/biorxiv/early/2016/04/06/047456.full.pdf

Seems mt-DNA M entered south Asia from the east, not the west. That makes the dates in this post quite possible. A northern route east. The final nail in the coffin of the great southern coastal migration.

andrew said...

"heidelbergensis ("Denisovans")."

Now that we have ancient DNA from an individual who can be verifiably determined from skeletal remains to be a heidelbergensis, and we have learned that ancient DNA does not share a clade with Denisovans, it is no longer accurate to equate H. heidelbergensis and Denisovans. They are pretty much irrefutably members of different species based upon very direct and solid ancient DNA evidence.

terryt said...

"Now that we have ancient DNA from an individual who can be verifiably determined from skeletal remains to be a heidelbergensis, and we have learned that ancient DNA does not share a clade with Denisovans"

I haven't seen that Any information? Or link?

eurologist said...

Andrew,

Nothing is ever straightforward. The genetically defined "Denisovans" lived much, much later than early or mid-time heidelbergensis - in fact, during a time when heidelbergensis fossil records dwindle to nothing.

However, the first paper by Meyer et al.
http://www.nature.com/news/hominin-dna-baffles-experts-1.14294
shows that Denisovans are related to heidelbergensis and/ or early Neanderthals via mtDNA, while we know that mainstream Neanderthals have mtDNA with much more recent relations to either Africa or the SE Europe/ SW Asia/ NE Africa triangle (i.e., modern humans).

Western Europe developed differently from the rest of Europe, and all the early signs of developing Neanderthal features are there. So, in my opinion, Sima de los Huesos is not characteristic of heidelbergensis in general - just of those western heidelbergensis that were already on their way to morph toward Neanderthals for quite some time (>~200,000 years). Given the time frame involved, it is clear that from there, many of the characteristic autosomal SNPs evolved that then later define genetically-sampled Neanderthals.

In summary, I think of Neanderthals as those who developed in western Europe from heidelbergensis, and only made it into E and SE Europe (and eventually into W Asia) at a much later time (~200,000 to 60,000 ya, respectively), while heidelbergensis also had those same ~600,000 years to differentiate and occupy E and SE Europe and much of Asia much earlier than Neanderthals.

Many fossils over a huge time frame can be and have been classified as heidelbergensis, long after the emergence of Neanderthals. Of course they evolved, but as a separate group from Neanderthals. But since they don't have the characteristic derived phenotype features of Neanderthals, I have no problem calling them the same name over their ~700,000 years existence.

If you have different papers in mind, please let me know.

terryt said...

"Now that we have ancient DNA from an individual who can be verifiably determined from skeletal remains to be a heidelbergensis, and we have learned that ancient DNA does not share a clade with Denisovans, it is no longer accurate to equate H. heidelbergensis and Denisovans".

I think I've found your source. Maju lists the paper.

http://www.nature.com/nature/journal/v531/n7595/full/nature17405.html

However I think you draw the wrong conclusion. The Sima de los Huesos fossils actually have Denisovan mt-DNA. Doesn't that show an intimate connection between heidelbergensis and Denisovan? The paper indicates that the Denisovans were quite widespread through northwestern Eurasia before being replaced by an expanding Neanderthal population. This tends to suggest a close connection between Denisovan and heidelbergensis.

"A mitochondrial DNA recovered from one of the specimens shares the previously described relationship to Denisovan mitochondrial DNAs, suggesting, among other possibilities, that the mitochondrial DNA gene pool of Neanderthals turned over later in their history".

Further:

"the Sima de los Huesos hominins were related to Neanderthals rather than to Denisovans, indicating that the population divergence between Neanderthals and Denisovans predates 430,000 years ago".

I seem to remember that the mt-DNA indicates that the common ancestor of Neanderthal and modern split from the Denisovan line around one million years ago. That's certainly more than 430,000 years ago.