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In the article they mention exercise. Basically your muscles squish your bones while you do physical activity.

What evolutionary pressure led to that? If I have to guess animals that were still able to hunt/move/... for longer were also able to mate for longer.

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This reminds me of the relatively recent discovery/realization of the “second heart” in our calves that pumps blood from the legs.

I thought that was pumping the lymph system. For which there is no heart (other than the muscle pumping?)

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