I have heard it said quite often, that a chimpanzee or a gorrilla is so strong that one could rip of a man's arm with one tug. so i typed it into google but i couldn't find anything concrete.  I then wondered if they actually could do this, and if they couldn't could they do it in several tugs, pulling constantly or twisting- no use of teeth allowed. It is not a credible answer to say: "yes, because they are X times stronger than an average human male". And by rip a man's arm off , I don't mean dislocation I mean actual dismemberment. Taking this further, what is the force required to tear off an average man's arm, that is, it's tensile strength. Also i have heard  that the original study that is the source of the 4-5 times stronger figure was flawed and that more recent studies put the bound much lower more like twice ......so........ could a world class human  weigthlifter dismember someone if they had the urge?

I have a theory that may work in conjunction with popular belief that dinosaurs were wiped out by meteor impact. Given the size of animal and plant life during the time and to some the seemingly laughable proportions ie huge bodies and small legs arms of some creatures. If gravitational strength was lower those creatures would not need strength in proportion to body mass or wieght.  Plants would/could grow larger taller without the confines of gravity as we know it. Could it also explain the seemingly impossible feats of strenth we debate over regarding placement of objects and the building of structures by our human ancestors. Scientists research and tell us of THE meteor impact that wiped out the dinosaurs. Could it be that over a period of time there was more than a couple of impacts that we can no longer find evidence of and that, and by changing the density and mass of the earth we now experience gravity at a higher strength. We know that physically we adapt ie loss of hair due to temperature change, creatures in caves being blind etc.