[LukeL]

Being a biped goes against evolution. You are taller thus easier to spot in tall grasses and in thick cover, your center of gravity changes making it easier to knock you over or trip, you can't run as fast, you will naturally have a smaller upper body thus and thus be weaker.

The only real advantage could be that your hands are now free, but how often do we use our hands when in motion? Most hunting and gathering can be done while sitting or standing in place

[Resolute Conservative]

... or maybe God knew what he was doing :)

[lastchance]

“but how often do we use our hands when in motion?”

You don’t drive on 195 in Miami during rush hour do you?

[Blue State Insurgent]

Unless, of course, it was an aquatic adaptation. Only in aquatic mammals do we find other mammal species with femurs aligned with spines.

The ‘aquatic ape theory’ also accounts for adaptations such as lack of body hair, prominent noses and webbed fingers.

[Reeses]

Most hunting and gathering can be done while sitting or standing in place

A hunting attack is quick, either you caught it or you didn't, but tribal warfare requires wielding weapons for extended periods of time since your battle opponent is about the same in capabilities. Armpit hair and sweat under stress provides needed lubrication for an extended fight, which no other animal has a need for. War is a special high speed form of evolution in that any advantage in genetics, culture, technology, teammanship is selected for in a few years rather than the many thousands of years natural selection takes. The losing side is often decisively and entirely killed off.