Review:
The different adaptive trajectories in Neanderthals and Homo sapiens and their implications for contemporary human physiological variation
Emma Pomeroy 2023 doi org/10.1016/j.cbpa.2023.111420 open access

•Hn are one of our closest evol.relatives.
•Contrasting & parallel evol.trajectories of Hn & Hs offer potential for insight into the evolution of physiology, anatomy & behaviour in both spp.
•Hn morphology has classically been interpreted as adaptation to cold climate, but high activity levels & muscle mass + a power/strength phenotype & diet may be implicated.
•Challenges in interpreting Hn adaptations highlight limitations to our understanding of current human diet, metabolism & physiology.
•Understanding Hn adaptations & evolution may ultimately help us gain greater insight into Hs variation & variability in diet, metabolism, physiology, morphology & activity.

Hn are our closest evol.cousins, but while Hn evolved in Eurasia, Hs (AMH) originated in Africa.(uncertain IMO --mv)
This contrasting evol.history has led to morphol. & genetic distinctions between our spp.
Hn are characterised by
- a rel.stocky build, high body mass,
- proportionally wide bodies & shorter limbs,
- a bell-shaped rib-cage & wide pelvis,
- a long, low cranial vault vs Hs.
Classic readings of Hn morphology link many of these traits to cold climate adaptations,
but these interpretations have been questioned:
alternative hypotheses incl. behavioural factors, dietary adaptations, locomotor specialisations, evol.history & neutral evol.processes have been invoked.
Hn (cf Hs) may have been adapted for strength & power, rather than endurance, and may have consumed a diet high in animal products.
But reviewing these hypotheses highlights a nr of limitations in our understanding of contemporary human physiology & metabolism, incl.
- the relationship between climate & morphology in Hs & Hn,
- physiol.limits on protein consumption,
- the relationship between gut morphology & diet.
Various relevant factors are clearly linked (e.g. diet, behaviour, metabolism, morphology, activity):
ultimately, a more integrated approach may be needed to fully understand Hn biology.
Variation among contemporary Hs may offer (with caveats) a useful model for understanding the evolution of Hn & Hs characteristics,
these in turn may further deepen our understanding of variability within & between contemporary humans.

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Short Communication:
Estimation of the upper diaphragm in KNM-WT 15000 (Homo erectus s.l.) and Kebara 2 (Homo neanderthalensis) using a Homo sapiens model
José M López-Rey cs 2023 JHE 185 doi org/10.1016/j.jhevol.2023.103442

•The diaphragm of extinct Homo might have been deeper & flatter than that of H.sapiens.
•Size of fossil diaphragm estimations are within the H.sapiens range of variation.
•Breathing kinematics might have been different in fossil Homo.

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Hn had still pachy-osteo-sclerosis (less than H.erectus = always in salt water?):
IOW, they still frequently dived (slow+shallow diving), probably mostly for shellfish.
This is confirmed by their
- even larger brain >Hs (DHA etc. in aquatic foods),
- projecting mid-face, big nose + large paranasal air-sinuses (frequent back-floating?),
- no chin & platycephaly (flat, dosally-shifted brain-skull) cf. streamline,
- large & wide thorax (O2 underwater),
- platypelloidy + longer & more horizontal femoral necks (lateral thigh movements+),
- platymeria (dorso-ventrally flattened femora) & shorter tibias & flatter feet,
- fossilisations along coasts & rivers (seasonally following the Meuse, Rhine... inland?).

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