there's some really interesting ideas going back as far as lamarck and darwin. federally funded take a nickel tour through some of those ideas that unite mind indulging us. >> it's one of those things where if it was a another mammal that moved on legs regular will be able to catch us more effectively we be able to do some science and say what is this other memo do? what is it eat literate mating patterns in which this form of locomotion is beneficial? and so as a scientist when you're trying to figure outut something about your selfie was want to look out into the natural world and say where else do we see examples like this? the fact that we don't have other mammals that habitually walk on two legs make this a really, really difficult scientific problem to solve. it's one ofro the reasons we haven't solved it. you can go back and take it right up until 2021 people are still hypothesizing why it was selectively advantageous for our ancestors got ideas about seeing over tall grass, that was back to lamarck. very interested in humans being able to stand c off int