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Friday, June 25, 2021

Was a Denisovan skull found in Harbin?


Another species? or maybe a Denisovan? A paper (The Innovation, DOI: 10.1016/j.xinn.2021.100130 and DOI: 10.1016/j.xinn.2021.100132, Massive cranium from Harbin in northeastern China establishes a new Middle Pleistocene human lineage) published today, describes a crania discovered in 1933 in Harbin, northern China, but only re-discovered a few years ago, and studied now.

The paper cautiously suggests in a covert manner that this Harbin skull may be a Denisovan one:

"The sister relationship between Harbin and Xiahe, as identified by Bayesian inference (but not parsimony analysis, see the supplemental information), is particularly interesting. The Xiahe mandible shows some proteomic features of the Denisovans, who were informally called “Homo sapiens altaiensis” or “Homo altaiensis,” and sediments from Baishiya Cave have yielded Denisovan mtDNA. The Harbin M2 also matches the known permanent Denisovan molars in size and root morphology, and, ever since the discovery of Denisovans, Asian Middle Pleistocene hominins, such as Dali, Jinniushan, and Xujiayao, have been suspected to represent an East Asian population of the Denisovans"

The remains have been dated to "a minimum age ... of ∼146 ka"

Regarding divergence from the Homo sapiens line, it has some interesting findings: (bold font is mine)

"The results of the Bayesian tip-dating analyses suggest that the Harbin and Xiahe fossils shared a common ancestor ∼188 ka (397–155 ka), and the clade, including the Harbin cranium and H. sapiens shared a common ancestor at ∼949 ka (1,041.41–875.25 ka). The Neanderthal-H. sapiens divergence time in our analysis was ∼1,007 ka (1,114–919 ka). This estimation falls in the range based on mtDNAs for the split between the basal Neanderthal (Sima de los Huesos) and the H. sapiens lineage, but is much older than the estimation based on nuclear DNAs for the splits between the Neanderthal and H. sapiens lineages. However, it is possible that this younger estimated divergence date is an artifact of statistical averaging between “super-archaic” and “recent gene flow” events. The common ancestor of the H. sapiens OTUs (NOTE: OTU is an "Operational Taxonomic Unit", and the term means that the beings under study share a given set of observed characters). included in our analysis is as old as ∼770 ka (922–622 ka), suggesting that the H. sapiens clade has a much deeper origin time than previously estimated. The Eurasian H. sapiens OTUs share a common ancestor ∼416 ka (534–305 ka) old. Outside of Africa, however, the earliest known H. sapiens fossil is only ∼210 ka.
There is a large time gap between the hypothetical common ancestor of Eurasian H. sapiens and the actual fossil record, from the Bayesian tip-dating analysis. One plausible hypothesis is that the ancestral population of Eurasian H. sapiens may have diversified in Africa for many millennia before they dispersed into Eurasia. Genetic studies on ancient DNA suggest that the initial genetic exchanges between Neanderthals and H. sapiens occurred between 468 and 219 ka, or between ∼370 and 100 ka, and the introgression may have originated through gene flow from an African source. Interestingly, not only does the estimated time of the introgression event between Neanderthals and H. sapiens roughly overlap our prediction for the age of the common ancestor of Eurasian H. sapiens, but the African origin of the introgression is also consistent with our African ancestral population hypothesis.
(...)
Africa is the major source of Homo dispersals. In total, ∼40% of all the dispersals are from Africa, while Africa also receives ∼22% dispersals from Asia and Europe. Instead of a unidirectional “out of Africa” model, a multi-directional “shuttle dispersal model” is more likely to explain the complex phylogenetic connections among African and Eurasian Homo species/populations.
"

Let's hope that DNA can be extracted from the skull, it could confirm that this man was in fact a Denisovan.


Patagonian Monsters - Cryptozoology, Myths & legends in Patagonia Copyright 2009-2014 by Austin Whittall © 

Thursday, June 24, 2021

New homo discovered in Israel a bridge between Neanderthals and Modern Humans?


A paper published in Science (A Middle Pleistocene Homo from Nesher Ramla, Israel) concludes that fossils found in Neshr Ramla (NR), Israel, are a "previously unrecognized group of hominins representing the last surviving populations of Middle Pleistocene Homo in Europe, southwest Asia, and Africa.".

The paper states:

"The NR fossils could represent late-surviving examples (140 to 120 ka) of a distinctive Southwest Asian MP Homo group, predating Levantine Neanderthals from Amud, Kebara, and Ein Qashish (70 to 50 ka). On the basis of their mosaic morphology showing a different degree of Neanderthal features, other MP Levantine fossils, whose taxonomic affinities have long been debated, from the sites of Qesem Cave (19), Zuttiyeh Cave (30), and probably Tabun Cave (31), might also be attributed to this group (supplementary text F). Adopting the cautious approach advocated by Mayr (32), we suggest addressing this Levantine MP paleodeme as the “Nesher Ramla Homo.” Its presence from ~420 to 120 ka ago in a geographically restricted area may have allowed for repeated interbreeding with modern human populations such as the people from Misliya Cave (20), a notion also supported by their shared technological tradition [(6); supplementary text F]. This scenario is compatible with evidence of an early (200 to 400 ka ago) gene flow between modern humans and Neanderthals (3, 4) and helps explain the variable expression of the dental and skeletal features of later Levantine fossils from the Skhul and Qafzeh populations, a phenomenon noted by anthropologists since the 1930s (31, 33). Moreover, a recent study of the Atapuerca SH and Arago dental remains (1) suggested the existence of more than one Homo lineage in MP Europe [see also (34)] and hypothesized the contribution of Levantine Homo groups carrying Neanderthal-like traits to European Homo lineages. The NR Homo, carrying Neanderthal-like traits, could thus represent the “source” population postulated in the demographic “sources and sinks” model (5), according to which Western Europe was repopulated through a series of successive migrations."


Patagonian Monsters - Cryptozoology, Myths & legends in Patagonia Copyright 2009-2021 by Austin Whittall ©