> How come we aren't like chimps, with eternally shredded bodies and cheese grater abs, provided we get the protein to support them?
There are several reasons: Chimps have a higher density of testosterone receptors with a higher sensitivity than humans. Compared to humans, they are essentially roided out all the time.
Humans are also hairless endurance hunters so we naturally have much larger fat reserves (15-25% of body weight vs <10% for chimps) in order to retain body heat and have enough energy to hunt prey till they collapse from exhaustion.
Not to mention that we really are much more similar to chimps than they’re giving us credit for. If we ate a relatively low calorie, high protein diet, and maintained an active lifestyle, we’d all be pretty damn muscular and lean. Not roided out muscular, but far more so than I think the average person expects. Our body composition is significantly determined by relatively near-zero fitness demands in modern life and an overabundance of the wrong kinds of calories
Yes just 150+ years ago most field work was done by hand, including moving rocks from fields, plowing with an animal (and a lot of human strength too). Just clearing new roads was mostly manual work.
(Sure, you could blow up things, but then you still had to clear the bits and level the road. Yes horses existed, but mostly it was just people.)
Every activity took more physical effort, everything was maintained manually. Even if you were a bookkeeper, it was all hand written, and any math was with a slide rule or on paper, or in your head. It takes more calories to move a slide rule than work a calculator, more to write than type.
And all the while, the muscles of the arm, and the upper body are being used as you press against that paper. Moving over a page meant arm and shoulder and back and more got a bit of workout. Every little bit added up.
Now we often type without moving our upper arms or shoulders. Without a change in back or upper torso movement.
It takes more calories to read than just sit still, more calories to think deeply than not.
Even going to the bathroom meant putting on boots and coat, and walking to the outhouse.
Yes indeed. People 100 years ago were more or less jacked on average from necessity alone. Better or worse I don't know but I do like me some menial labor on the reg.
Heat retention would benefit an ambush hunter in a cold climate whereas heat exhaustion is one of the ways endurance hunters catch their prey in hot climes.
> Humans are also hairless endurance hunters
It's something we can do but the diversity of habitats, prey and techniques humans feed themselves with is far greater than what feels like an over-indexing on specific extant savannah tribes as if they are proto-human relics. Do you need to out run a fish or an oyster? Why would you run after a rabbit instead of waiting for it near it's burrow? etc.
Personally I bear little resemblance to an endurance runner so one might assume no shortage of forest/mountain dwellers in my genes given short thick legs. Built for sprinting, climbing and carrying but, to my despair, incurably injury prone at endurance running.
> Humans are also hairless endurance hunters
really? who said that? just one of many tactics we use. and obviously weve evolved to be good runners, we're bipedal. i imagine ostriches are similarly built for long distance running
There are several reasons: Chimps have a higher density of testosterone receptors with a higher sensitivity than humans. Compared to humans, they are essentially roided out all the time.
Humans are also hairless endurance hunters so we naturally have much larger fat reserves (15-25% of body weight vs <10% for chimps) in order to retain body heat and have enough energy to hunt prey till they collapse from exhaustion.