The question of exactly how humans fought their way to the top of the food chain may have become a little easier to answer.  As KJZZ's Tony Ganzer explains, all humans had to do was stand-up.

TG: In the late 1960s Rod Searling's Twilight Zone kicked off a kind of monkey madness, with groundbreaking insights into the Planet of the Apes.  In this scene, planet leaders try a man for being a man,

Ape cut:  "This exhibit is a man, and therefore has no rights under ape law.  He is a man isn't he? He's unlike any man you know..ANSWER THE QUESTION DOCTOR."

Man stands on trial before the Ape court.

TG: Fortunately this is not the way things turned out.  Humans may have gotten a leg-up along the way.

Reichlan:  "It was probably one of the first adaptations that made homonids more human."

TG: David Reichlan is an assistant professor of anthropology at the University of Arizona.  He was part of a team of researchers looking at how much energy chimpanzees use while walking, as compared to their human counterparts.

Reichlan: "Humans use 75 percent less energy than chimpanzees giving huge benefits over chimps."

TG: These benefits over chimp energy usage would've allowed early humans to move more efficiently, and thus spend energy elsewhere.

Reichlan: "Some savings would then have been used on reproductions which is the name of the game when it comes to evolution."

TG: If this is such a good idea, why haven't the chimps figured it out?  Reichlan says chimpanzees were probably never under the pressure to change their movement, and a move toward walking may have taken away from their tree climbing skills.  But still, understanding why bipedalism, or two-leg walking, evolved may give a look into early humans.

Reichlan: "Understanding why bipedalism evolved is understanding why humans evolved essentially."

TG: And fortunately humans made it to the top of the food chain.

Ape cut:  "He is not being tried, he is being disposed of..."

For KJZZ, I'm Tony Ganzer.

Avoiding Apes...on KJZZ