Marc Verha
Tue, Apr-22-08, 17:16
Thanks, m3d.
http://biology.plosjournals.org/archive/1545-7885/3/11/figure-
/10.1371_journa
l.pbio.0030380.g001-L.jpg
I don't think the gorillas learned from humans how to use a
stick to measure the depth of the water. Orangs use tools,
chimps use tools, humans use tools: no wonder gorillas use
tools. Tool use in mammals is often correlated to durophagy &
thick enamel. Early hominids-pongids typically had thick
enamel (eg, Heliopith, Austriacopith in coastal forests) or
super-thick enamel (eg, Ouranopith, Samburupith, Nakalipith,
Chororapith, A.boisei//robustus in open wetlands), but those
in wet forests often had thinner enamel (Dryopith, Oreopith,
Ardipith...).
It's striking how the early hominids in Africa c.10-7 Ma
were large wetland-dwellers with thick enamel (gorilla-sized
or almost): Nakali-Chorora-Samburupith-Sahelanthr. It's
possible that all hominids (not only gorillas, but also
chimps, bonobos & humans) had gorilla-sized ancestors,
possibly in +-open wetlands, probably wading bipedally,
possibly with a diet overlapping that of gorillas: AHV
(aquatic herbaceous vegetation), fruits, sedges, papyrus &
perhaps bamboo, but the much thicker enamel than in gorillas
suggests also nuts & hard-shelled fruits &/or hard-helled
invertebrates, see the work of Shabel (AAPA abstracts 2007 &
2008) on durophagy in hominids.
--Marc
> Gorilla wading, feeding in water ... She began to cross the
> pool walking bipedally, but after her first steps the water
> quickly became waist deep and she returned to the pool edge.
> Leah then re-entered again bipedally and grabbed the
> straight branch in front of her with her right hand .
> Relative to Leah's body size we estimated the leafless
> branch as being approximately 1 m long and 2 cm thick. Leah
> then detached the stick and, stretching forward with it in
> her right hand, seemed to use it to test the water depth or
> substrate stability: she grasped the stick firmly and
> repeatedly prodded the water in front of her with the end of
> the stick. First Observation of Tool Use in Wild Gorillas.
> Thomas Breuer, Mireille Ndoundou-Hockemba1, Vicki Fishlock
> PLoS 2005 http://tinyurl.com/5tcz7p ... The people who
> documented the behavior suggest that the gorillas possibly
> learned their unusual behavior from interactions with
> humans. Captive gorillas have been documented picking up
> stone throwing from their chimpanzee neighbors, so it's not
> too improbably that wild gorillas could pick up grass and
> branch hurling from human neighbors. Non-Human Primate Tool
> Use: Gorillas Weilding Weapons, Macaques & Mirror Neurons
> Primatology.net January. 2008 http://tinyurl.com/6pw3ka
> Are we observing the behaviour of gorillas and other apes,
> or are they observing ours ... ---m3d
http://biology.plosjournals.org/archive/1545-7885/3/11/figure-
/10.1371_journa
l.pbio.0030380.g001-L.jpg
I don't think the gorillas learned from humans how to use a
stick to measure the depth of the water. Orangs use tools,
chimps use tools, humans use tools: no wonder gorillas use
tools. Tool use in mammals is often correlated to durophagy &
thick enamel. Early hominids-pongids typically had thick
enamel (eg, Heliopith, Austriacopith in coastal forests) or
super-thick enamel (eg, Ouranopith, Samburupith, Nakalipith,
Chororapith, A.boisei//robustus in open wetlands), but those
in wet forests often had thinner enamel (Dryopith, Oreopith,
Ardipith...).
It's striking how the early hominids in Africa c.10-7 Ma
were large wetland-dwellers with thick enamel (gorilla-sized
or almost): Nakali-Chorora-Samburupith-Sahelanthr. It's
possible that all hominids (not only gorillas, but also
chimps, bonobos & humans) had gorilla-sized ancestors,
possibly in +-open wetlands, probably wading bipedally,
possibly with a diet overlapping that of gorillas: AHV
(aquatic herbaceous vegetation), fruits, sedges, papyrus &
perhaps bamboo, but the much thicker enamel than in gorillas
suggests also nuts & hard-shelled fruits &/or hard-helled
invertebrates, see the work of Shabel (AAPA abstracts 2007 &
2008) on durophagy in hominids.
--Marc
> Gorilla wading, feeding in water ... She began to cross the
> pool walking bipedally, but after her first steps the water
> quickly became waist deep and she returned to the pool edge.
> Leah then re-entered again bipedally and grabbed the
> straight branch in front of her with her right hand .
> Relative to Leah's body size we estimated the leafless
> branch as being approximately 1 m long and 2 cm thick. Leah
> then detached the stick and, stretching forward with it in
> her right hand, seemed to use it to test the water depth or
> substrate stability: she grasped the stick firmly and
> repeatedly prodded the water in front of her with the end of
> the stick. First Observation of Tool Use in Wild Gorillas.
> Thomas Breuer, Mireille Ndoundou-Hockemba1, Vicki Fishlock
> PLoS 2005 http://tinyurl.com/5tcz7p ... The people who
> documented the behavior suggest that the gorillas possibly
> learned their unusual behavior from interactions with
> humans. Captive gorillas have been documented picking up
> stone throwing from their chimpanzee neighbors, so it's not
> too improbably that wild gorillas could pick up grass and
> branch hurling from human neighbors. Non-Human Primate Tool
> Use: Gorillas Weilding Weapons, Macaques & Mirror Neurons
> Primatology.net January. 2008 http://tinyurl.com/6pw3ka
> Are we observing the behaviour of gorillas and other apes,
> or are they observing ours ... ---m3d