All of our extant relatives are quadrupedalism, but humans are not. Does anyone know why we evolved to be bipedal? I always assumed it was because of preventing heating absorption.

It saved fuel.

We went through a semi-aquatic period, forced to walk upright.      That's why we have downward slanting noses.   You can't actually smell better that way, no predator has a downward slanting nose.   In fact, when you smell a bar-b-que, you'll tend to tilt your head back to take in the whole aroma.   The only thing a downward slanting nose allows is for someone to swim forward in water, without the water rushing up the nasal cavity.      No other primate has a downward slanting nose.     We also cry copious saltwater tears, same salinity as ocean water.     And, we have lots of subcutaneus fat, like dolphins and other aquatic mammals.     Bipedalism makes us easy prey on land, fortunately we had big brains and held our own with faster/stronger predators.

Because thats the way God made us.

Hehe, I was coming to post the exact same thing. Better prepare for a flamestorm good buddy!

It is easier to play soccer that way.

Lol I have already adorned my anti-flame suit so I should be good

sigh I should go and get my evolution notes to make sure i'm not making stuff up but basically becoming bipedal gave one really significant evolutionary advantage... use of our hands. Being able to use our hands, well... is pretty huge haha... can protect from predators from afar by throwing things, communication, using tools, etc... Mind you bipedal locomotion has quite a few flaws in itself but nontheless we're still better off by having the use of our hands.

As an aside, because of bipedal locomotion humans are born several months premature compaired to other animals (think about it.... newborn babies are pretty useless and don't even move) because the shape of our pelvis was adapted to bipedal locomotion and human head would not be able to fit through. :)

I could explain this much better but I don't feel like finding my notes :)

And it makes it easier to turn around and walk away because nobody wants to watch.

Ancestors of primates, enough said. If you don't like that the only other reasonble response is some supreme being made us that way.