On Wednesday, October 5, 2022 at 6:00:18 AM UTC-4, littor...@gmail.com wrote:
Teeth, prenatal growth rates, and the evolution of human-like pregnancy in later Homo
Tesla A Monson cs 2022 PNAS 119 (41) e2200689119
doi org/10.1073/pnas.2200689119
Hs are characterized by having very large brains (endocranial volume ECV) vs body size.
Because gestation is critically linked to ECV, pregnancy is an important, but elusive aspect of hominid evolution.
We developed 2 methods for reconstructing prenatal growth during this earliest phase of life-history, using ECV & dental morphology.
Our results indicate a significant increase in prenatal growth rates (PGRs) throughout the terminal Miocene & Plio-Pleistocene, with the evolution of human-like PGRs in later Homo <1 Ma.
These results
- align with fossilized pelvic & cranial anatomy, to support the evolution of human-like pregnancy in the Pleistocene,
- open up possibilities for novel ways to explore the evolution of hominid gestation via dental variation.
Abstract
Evidence of how gestational parameters evolved is essential to understanding this fundamental stage of human life.
Until now, these data seemed elusive, given the skeletal bias of the fossil record.
We demonstrate:
dentition provides a window into the life of neonates:
teeth begin to form in utero, and are intimately ass.x gestational development.
We measured the molar dentition for 608 catarrhines,
we collected data on PGR & ECV for 19 primate genera from the literature. We found:
- PGR & ECV are highly correlated (R2=.93, P<.001),
- molar proportions are significantly correlated with PGR (P=.004) & log-transformed ECV (P=.001).
From these correlations, we developed 2 methods for reconstructing PGR in the fossil record,
- one using ECV,
- one using molar proportions.
Dental proportions reconstruct hominid ECV (R2=.81, P<.001), a result that can be extrapolated to PGR.
Teeth dominate fossil assemblages: our findings greatly expand our ability to investigate life-history in the fossil record.
Fossil ECVs & dental measurements from 13 hominid spp both support significantly increasing PGR throughout the terminal-Miocene & Plio-Pleistocene, reflecting known evolutionary changes.
Together with pelvic & endocranial morphology, reconstructed PGRs indicate the need for increasing maternal energetics during pregnancy over the last 6 Ma, reaching a human-like PGR (more similar to Hs than to apes) & ECV in later Homo <1 Ma.
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Large brains & longer gestation are typical for aquatic mammals.
The correlation with molar proportions is less clear IMO.
Somebody:
Now MV claims that AMHs is typical for aquatic mammal.
How stupid must you be to deny that aquatic mammals are furless, fat, flat-footed, large-brained etc.?
Only incredible imbeciles deny that our ancestors were semi-aquatic until well into the Pleistocene.
Only incredible imbeciles believe our early-Pleistocene ancestors ran after antelopes over African savannas.
Why don't these idiots inform a little bit befroe trying to say something?? Google
- "aquarboreal" for Mio-Pliocene hominoids evolution,
- "coastal dispersal Pleistoce Homo" for human evolution.
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