Selection of endurance capabilities and the trade-off between pressure and volume in the evolution of the human heart
Robert Shave, Daniel Lieberman ... 2019
PNAS 116:19905-10
https://doi.org/10.1073/pnas.1906902116

Unlike other great apes, humans evolved multisystem capabilities for moderate-intensity EPA, but it is unknown if selection acted similarly on the heart. We present data from a sample of humans, chimpanzees, and gorillas showing that the human (LV)
evolved numerous features that help to augment stroke volume (SV), enabling moderate-intensity EPA. We also show that phenotypic plasticity of the human LV trades off pressure adaptations for volume capabilities, becoming more similar to a chimpanzee-
like heart in response to physical inactivity or chronic pressure loading. Consequently, the derived human heart appears partly dependent upon moderate EPA and its absence, in combination with a highly processed diet, likely contributes to the modern
epidemic of hypertensive heart disease.

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This is a beautiful example of traditional anthropocentric just-so thinking, that apes leaving the forests evolved into "hominins" running bipedally over open plains:
the authors assume that human ancestors initially hunted & gathered, and then try to collect data that fit this unscientific idea.
In fact, their data (e.g. stroke volume, cardiac plasticity) are better explained by a littoral lifestyle (incl. wading bipedally & shallow-diving), which they didn't even consider:
early-Pleistocene Homo dispersed intercontinentally along African & Eurasian coasts, rivers & islands, collecting different waterside & shallow-aquatic foods, rich in brain-specific nutrients (DHA etc., absent in savannas).



Endurance Running Versus Underwater Foraging:
An Anatomical and Palaeoecological Perspective
Stephen Munro 2013 Hum.Evol.28:201-212

The dominant theory of human evolution has long been that humans evolved as a result of leaving the forests and becoming better adapted to life in more open, arid habitats (terrestrial model). This idea pre-dates Darwin's ideas on natural selection, has
never been subjected to rigorous scientific scrutiny, and is far less credible than the alternative model proposed here: that human evolution occurred as a result of adaptations to a littoral environment in which ancestral populations for part of the
time foraged under water for slow moving, immobile and sessile resources such as shellfish; dispersed around coasts; and moved up rivers to inland wetlands, including savannas.
It is argued here that the combination of anatomical and palaeoecological data are incompatible with the idea that 'erectine grade' hominids (characterised by relatively heavy cranial and post-cranial bones and a long, low braincase) were long distance
runners over arid landscapes, but completely compatible with a waterside dwelling lifestyle, including slow, part-time underwater foraging in relatively shallow waters.

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