Re: bipedalism and AAH

9 May 1995 18:20:25 GMT

Pat Dooley ( wrote:
: >And as I noted elsewhere recently, Joel Brown did some good work back in
: >the '80s figuring out the ecological roles of quadrupedal, bipedal, and
: >flying species in the Arizona desert. (See JTB about 1985.) Bipedal
: >species (Kangaroo Rats) are adapted to longer-range search than the
: >quadrupedal species (and birds take that strategy even further). They
: >might not have been more efficient (in fact there's a theorem in
: >mathematical biology that they cannot be more efficient), but they are
: >dependent on their bipedalism to make their living.

: Bogus.

: Kangaroo rats, like their convergent Australian relatives, have large
: counter-
: balancing tails that are integral to their bipedalism. Cut off their tails
: and they
: go no place fast.

: Are their spines parallel to their legs? No.

: Are their pelvises parallel to their legs? No.

: Are they tail-less? No.

: Are they bipedal in the human sense? No.

: Pat D

Read the damn paper first before you comment, please. Joel did some good
work. The key parameter is not movement efficiency, but search
efficiency. You can get that with saltatory movement (with a tail
required) and eyes held high off the ground or with tree climbing (no
tail) and eyes held high off the ground.

Harry Erwin
PhD student in comp neurosci: "Glitches happen" & "Meaning is emotional"