Humans: 2 Legs or 4?

I got in a silly dispute with a guy named Chad posting over at Formosa Neijia, I'm not even sure where it is now, so don't bother going to look for it, but it did get me thinking.

Why am I so sure we are four legged creatures?  His argument was that we have evolved into a two legged creature, that our bones are all oriented differently, that our pelvic structure is quite different from what it was when we were four legged.  Presumably our minds have evolved quite a bit too.  No doubt there is some truth there.  I remember reading a study somewhere about evolutionary divergence between people wearing shoes and people going barefoot.

But I assure you, if you could overcome the taboo of walking on all fours, each and everyone one of you could make the transition very quickly.  People under 40 could easily go 6 hours on all fours, today,  without any training what-so-ever.   People over 40 might need a week to adjust.

If people gave up the taboo against walking on all fours, every workout gym in the country would be shut down over night.  I'm thinking that if I ever have a kid I'm going to teach him/her to catch a Frisbee with his/her mouth while running and jumping on all fours.

I wonder just how much of the structural change in human bones is due to usage and training.  The fact that we walk on two legs all the time may be the more significant factor in our development.  There may be very little actually evolutionary difference.  We could test this if we were to raise a few kids to only walk on all fours.  Would they actually develop the structural differences Chad was referring to?

Anyone want to volunteer their kids for that?

Oh yeah, I left something out of this story.  How do I know all this?

Back when I was in my early twenties, me and a bunch of anarchy inspired dancers made up some fake letterhead that said, "Community Health Study Group."  On the letterhead we wrote to the San Francisco Police Department asking for a permit to parade through the Financial District.  The letter said, "We are planning an educational procession to draw attention to the contemporary and traditional medicinal uses of clay on the skin." They gave us the permit and a police escort.

After collecting about twenty buckets of high quality mud from a nearby ocean side, open space, about 40 of us gathered in a park on the edge of the Financial District and  started to cover our bodies in mud.  We made two rules before starting.

  1. No speaking any known language.

  2. No walking upright.

I participated in the "event" five years in a row.  After the first year we figured out that tennis shoes, knee pads, and underwear were a good idea.  No one ever had any trouble becoming a four legged animal for 4 hours.  After covering yourself in mud, the "stuff" on city streets doesn't register as "dirt" anymore.  (Not speaking any known language probably helps with that too.)  As far as I know it's still going on.

UPDATE: Unfortunately this particular video shows some people "cheating," shame on them. Anyway, what I said is true!