Tuesday, June 6, 2023

Story Of Human Evolution Not Actually Rewritten

Deep inside a South African cave, researchers say they have discovered graves dug by our ancient, small-brained relatives more than 100,000 years before the oldest known human burials, a claim that would revise the story of our evolution.
From the Washington Post.

Yes, this story about Homo naledi is cool.

Does it revise our story of evolution? 

No.

Does it spark debate among people who knew the existing story prior to this discovery? 

Not really, beyond the fine details of interpretation of the site.

This is a side story about a dead end hominin species that existed contemporaneously in Africa with the most direct ancestors of modern humans. It is basically a story from The Silmarillion of hominin evolution. It is entertaining, especially for hard core human evolution fans, but it doesn't really advance the plot.

Meanwhile, John Hawks discusses another recent paper he has co-authored on Homo Naledi from ten years after the original find about H. Naledi teeth.
More than 150 hominin teeth, dated to ∼330–241 thousand years ago, were recovered during the 2013–2015 excavations of the Dinaledi Chamber of the Rising Star cave system, South Africa. These fossils comprise the first large single-site sample of hominin teeth from the Middle Pleistocene of Africa. Though scattered remains attributable to Homo sapiens, or their possible lineal ancestors, are known from older and younger sites across the continent, the distinctive morphological feature set of the Dinaledi teeth supports the recognition of a novel hominin species, Homo naledi. This material provides evidence of African Homo lineage diversity that lasts until at least the Middle Pleistocene. Here, a catalog, anatomical descriptions, and details of preservation and taphonomic alteration are provided for the Dinaledi teeth. Where possible, provisional associations among teeth are also proposed. To facilitate future research, we also provide access to a catalog of surface files of the Rising Star jaws and teeth.
Delezene, L. K., Skinner, M. M., Bailey, S. E., Brophy, J. K., Elliott, M. C., Gurtov, A., Irish, J. D., Moggi-Cecchi, J., de Ruiter, D. J., Hawks, J., & Berger, L. R., "Descriptive catalog of Homo naledi dental remains from the 2013 to 2015 excavations of the Dinaledi Chamber, site U.W. 101, within the Rising Star cave system, South Africa." 180  Journal of Human Evolution 103372 (2023) 

8 comments:

neo said...

how is Homo naledi distinct from H habilis

andrew said...

https://en.wikipedia.org/wiki/Homo_naledi v. https://en.wikipedia.org/wiki/Homo_habilis

One obvious point is brain size:

H. Naledi 465–610 cm3
H. Habilis 500–900 cm3
H. Sapiens 1,270–1,330 cm3

Neanderthals are a bit bigger than Sapiens and we have no Denisovan skulls to measure.

Naledi averaged averaged 4'9" in height and 88 lbs. in weight. Habilis would have been similar in height (maybe 4'10") but mean lean (maybe 77 lbs.)

Naledi teeth indicate that they ate extreme tough foods. Habilis teeth indicate much softer foods.

Naledi made more primitive Acheulean tools, while Habilis made more sophisticated Oldowan tools.

The time frames are also different. Habilis was in East and South Africa about 2.31 million years ago to 1.65 million years ago (mya). Naledi is found South Africa dating to the Middle Pleistocene 335,000–236,000 years ago in South Africa but not so far in East Africa.

neo said...

One obvious point is brain size:

H. Naledi 465–610 cm3
H. Habilis 500–900 cm3

that is a large overlap

The time frames are also different. Habilis was in East and South Africa about 2.31 million years ago to 1.65 million years ago (mya). Naledi is found South Africa dating to the Middle Pleistocene 335,000–236,000 years ago in South Africa but not so far in East Africa.

could be a relic population of Habilis migration

andrew said...

@neo

Suffice it to say that your speculation is far outside the accepted phylogeny in hominin physical anthropology.

neo said...


Elife

. 2017 May 9;6:e24234.
doi: 10.7554/eLife.24234.
Homo naledi and Pleistocene hominin evolution in subequatorial Africa
Lee R Berger 1 , John Hawks 1 2 , Paul Hgm Dirks 1 3 , Marina Elliott 1 , Eric M Roberts 1 3
Affiliations

PMID: 28483041 PMCID: PMC5423770 DOI: 10.7554/eLife.24234

Free PMC article


"....It is now evident that a diversity of hominin lineages existed in this region, with some divergent lineages contributing DNA to living humans and at least H. naledi representing a survivor from the earliest stages of diversification within Homo. The existence of a diverse array of hominins..."

Ryan said...

"Naledi made more primitive Acheulean tools, while Habilis made more sophisticated Oldowan tools."

I don't believe we have any information to that effect whatsoever.

andrew said...

@Ryan The citations can be found in the top two links in my first comment "June 7, 2023 at 11:19 AM"

Ryan said...

@Andrew - Here's what it says: "Though H. naledi remains are not associated with any stone tools, it is likely they produced Early Stone Age (Acheulean and possibly the earlier Oldowan) or Middle Stone Age industries because they have the same adaptations to the hand as other human species which are implicated in tool production."

So no, we don't know what tools they used (if any) aside from the hearths and other evidence of fire. More to learn and discover!