Subject: why do we look the way we do?

What I mean is, if on the same earth, although not the same climate, there once 
were dinosaures, and after armagadon we slowly evolve.
Now could that be because it's more energy sufficient being like we than a 
dinosaure today and if so why.

p.s: I don't know if you saw the movie K-Pax, but if you did you'll recall when 
he said: "on earth I look like a human, on my planet K-Pax I look like a K-
paxian" and he compared this phenomenon to a soap buble. Like he said: "why is 
a soap buble spheric, because it's the most energy sufficient in its 
conditions".

So do all of this apply to us also? And if so, why did more simple organisms 
not evolve to a different shape, like bateria and other creatures? 

Re: why do we look the way we do?