ELISABETH LICKINDORF 20.12.99 Mail & Guardian <https://ntz.info/gen/b00583.html#id03294>
Ronald Clarke used circus chimpanzees to prove his theory about the Laetoli footprints in Tanzania.


20 years ago, Ronald Clarke was invited by Mary Leakey to continue an excavation begun at Laetoli in Tanzania.
Paul Abell had discovered a hominid heel impression in 3,6-Ma volcanic tuff. Subsequent excavation by Tim White uncovered the first footprints of a trail made, apparently, by 2 individuals.
Clarke accepted Leakey's invitation - and inadvertently entered an arena of fierce debate.
The prints were clearly made by individuals walking bipedally,
but Leakey and Clarke differed in their interpretations.
Clarke:
"I was struck by the fact that the prints did not seem fully human:
there was separation of the big toe from the other toes,
and, behind the end of the big toe, a smallish round impression that looked like a toe.
Mary (advised by other experts) insisted it was Homo,
and that the 2nd of the 2 trails must have been made by 1 individual walking in another's footprints.
I, OTOH, thought the prints were [made by 1 creature:] ape-like with long toes - not fully human."

Public outcry greeted Clarke when he stated his views in 1985 at the conference celebrating the 60th anniversary of the Taung discovery,
and he didn't publish them.
But he was not convinced he was wrong.

Later that year, he arranged an experiment with the Boswell Wilkie Circus in J'burg (& a friendly trainer) to coax a female & a male chimpanzee to walk next to each other bipedally over wet sand:
"The circus chimps produced prints that looked like the Laetoli footprints.
Not only did those of the male look similar
(big toe aligned with the others + the 'apparent' toe within, caused by the imprint of a joint),
but also the female had a completely different footprint.
She was more timid:
she dug her heels in, and spread her big toe wide, and kicked up a lot of sand, he was confident, and tended to walk with his big toe most often close to the other toes:
"The circus prints showed that apes with toes capable of opening up to a wide degree can also bring that toe into alignment when they walk upright:
they are capable of doing both."
The conclusion (Clarke 1999 S.Afr.J Sci.95:477):
"when the chimpanzee walked bipedally in a confident manner, it preferred to align its big toe with the others, presumably for more efficient locomotion".

The foot bones of the 3,33-Ma skeleton at Sterkfontein have inadvertently given Clarke a further (perhaps clinching) argument.
Comparing the evidence of the foot-bones, the footprints in Tanzania & those made by the circus chimps, Clarke has announced:
"The Laetoli footprints could have been made by feet with slightly divergent big toes as represented by the StF Australopithecus StW 573."

____


AFAICS, some of the footprints most resemble the foot soles of a mountain gorilla female (Schultz).
IOW, there's nothing that shows that "human ancestors" made the footprints: google "incredible logical mistakes PA 2019 Verhaegen"

--- SoupGate-Win32 v1.05
* Origin: fsxNet Usenet Gateway (21:1/5)