Suppose that approximately 2 million years ago, a mutation developed in hominids that allowed males (and only males) to access magic-type abilities. For the purpose of this question, consider this to be telekinesis (TK) that's roughly twice as efficient as using muscles, energy wise. It rapidly spreads through the population and is carried through until something similar to modern humans develop.
- TK does not depend on how in-shape the body is at all, it's an entirely separate system. It does draw from your body's reserves but in a different way.
- It's not efficient for long-ranged travel. You're better off using a horse or your own legs.
- TK is powerful but not a trump card in combat, it has strengths and weaknesses just like any other technique. The best groups at fighting and hunting combine the two, so for example 10 TKs + 10 normals would beat 20 TKs or 20 normals. TK requires enough mental concentration that it's not effective to try and combine it with regular combat techniques, any single individual can only use one or the other.
Presumably this mutation would change evolutionary selectors. Specifically, I'm wondering the following:
Would this reverse the "classic" human sexual dimorphism? Would females develop as larger and stronger without access to TK (or at least stay the same), with males becoming smaller and more efficient? Would it be the same as we are, for different reasons? Or would something else happen entirely?
Edit: The current answers could very well be correct, but I wanted to address my logic specifically since I'm not seeing it considered yet. (So basically, if I am wrong, please tell me why in your answer).
Evolution isn't strictly better/faster/stronger. It's about the fittest, and fittest can also mean things like adaptive and efficient.
TK would act as a replacement for physical muscles in many situations. It seems to me that this would favor smaller males, as they would be better long-distance runners who require less food in times of scarcity, while still being just as capable due to their TK.
Secondarily, due to Comparative Advantage, females would start selecting to be stronger and larger. It's more efficient to have 5 TK/5 normals than just 10 TKs, so primates would have an advantage if females took over the less-efficient big/strong role while males concentrated on their more powerful TK role.
It is also possible that my timeline is too short, and 2 million years isn't enough time for these differences to develop - if that's the case I'd be interested in knowing how long it would have to be.