Interspecies Conflict/comparative strength
My question is basically all about strength. Why is it, on a physiological level that we humans are weaker pound for pound than other apes? Is it in our structure, our muscles, or is it simply a distribution of musculature? For example, I'm a powerlifter, and I weigh roughly 138-143 lb.s at any given time of the year. Now I can bench press roughly 320, squat around 410 and I deadlift about 430. Now take a chimpanzee of roughly the same weight, and he would absolutely destroy me in strength. Now besides being beside myself in jealousy, I'm curious as to how it is that these apes seem to be that much stronger than us, or even someone that trains like me. Also, I've heard that neanderthal man may have been way stronger, and way more athletic than us today. Especially us today. So how much more would you estimate a neanderthal man or any other early human's strength and athleticism to be?
This boils down to muscle usage for a particular species. Chimpanzees (as well as other wild animals) have evolved to have the muscle strength to accomplish what they need to do to survive. There are certain events (hunting, fighting, locomotion through challenging areas of habitat, escaping from enemies, etc) animals must deal with in life, and their bodies have been fashioned to handle these events to ensure survival of the species. Humans have the ability to reason (and create tools and devices) and are able to accomplish these goals without having or needing the great strength most animals possess. When humans hunt deer, we don't chase them down, tackle them, and overpower them. We simply use a rifle. If threatened by a large animal, we use a tool or device to effect our escape or retreat into a vehicle or structure. Humans survive in this world using brains over brawn, and animals don't have the same luxuries our brainpower has afforded us. Lions tackle buffalo to obtain beef; humans have it handed to them through a drive-thru window.
You, as a powerlifter, have probably made the muscles you have as strong as you can make them. In many ways you are twice as strong as most people your size (how many people weighing 143lbs can bench 160lbs?). Estimates for chimpanzees' strength compared to humans varies greatly (as low as 2 times as strong and as high as 7 times as strong). I would guess that 4 times as strong (lb for lb) is a reasonable estimation. The muscles chimpanzees have are geared for strength more so than our own. Our muscles aren't inferior, they are just used differently (imagine a chimpanzee trying to thread a needle or swiftly solve a Rubik's cube).
Neanderthals, because of their livelihoods, needed to be stronger than humans of today. It's much the same reason that chimpanzees are stronger than we are, but to a lesser degree. Neanderthals used fire and tools to make surviving easier, but obviously didn't have the modern conveniences (or level of intelligence) of today's humans. They didn't need a chimpanzee's strength, but enough to operate in their habitat. Twice as strong as modern humans would be my guess. A powerlifter (such as yourself) is probably on par with the average Neanderthal in regards to strength. I imagine Neanderthals were more athletic than today's humans based on the running, jumping, lifting, and throwing they had to everyday to accomplish their survival goals, but people that train for triathlons probably aren't far behind.
Every animal (including humans) have muscles suited for what they need to do. The average construction worker is probably stronger than the average accountant (not an example of muscle evolution, just usage). A leopard is stronger than a cheetah of equal weight because it needs to be able to drag large prey up into trees (which a cheetah can't do). However, a leopard can't attain the speed of a car on the highway in 3 seconds to mow down a gazelle (which a cheetah can do). It all about having the right muscles for the job.