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All content in this area was uploaded by Andrew Planet on Jul 12, 2015
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Human bipedalism evolving through dragging branches as building material or tools
I've noticed in several different videos chimpanzees that walk considerable distances upright and
bipedally when they pull on tree branches by dragging from behind them. I myself used to walk
at very steep angles relative to the rock face I was treading on by pulling on long branches I'd cut
down when I used to work in the local nature reserve. Their weight and drag as they got caught
up with uncut trees would facilitate my standing upright at a very steep angle, balanced by my
grip on them. I'd use the gravity assist of the steep rock face to use less energy in transporting
the branches.
Could have our ancestors have evolved being upright by virtue of their ability to pull branches
from behind? I wonder if evidence for this could be more prone to be found in a formerly hilly
grassland type environment rather than plain flat savanna? Perhaps for either argumentation it
makes no difference as long as the adaptation was for pulling from behind. Maybe they would
have used the branches for habitat construction, as in primeval hominid huts, a step up from
chimpanzee nests. Stronger built habitats would afford them better defense from predation and
impart a more comfortable quality of life during rest periods. Also, carrying a heavy short branch
from behind, as in a club (I've also seen this in a video), would allow walking bipedally.
I first wrote the above in http://www.smithsonianmag.com/science-nature/becoming-human-