Nasalis & Homo

[Marc Verha]

"The Proboscis Monkey lifestyle is both arboreal and
amphibious, with its mangrove swamp and riverine environment
containing forest, dry land, shallow water allowing wading,
and deep water requiring swimming. Like other similar monkeys,
the Proboscis Monkey climbs well. It is also a proficient
swimmer, often swimming from island to island, and has been
picked up by fishing boats in open ocean a mile from shore.
While wading, the monkey uses an upright posture, with the
females carrying infants on their hip. Troops have been filmed
continuing to walk upright, in single file, along forest
trails when they emerge on land, the only non-human mammal,
with the exception of gibbons and giant pangolins, known to
use this form of locomotion for any length of time."
http://en.wikipedia.org/wiki/Proboscis_Monkey

Chris Stringer: "I have agreed that we lack plausible models
for the origins of bipedalism and have agreed that wading in
water can facilitate bipedal locomotion (as observed in other
normally quadrupedal primates). I have never said that this
must have been the forcing mechanism in hominids, but I do
consider it plausible."

http://allserv.rug.ac.be/~mvaneech/outthere.htm
http://groups.yahoo.com/group/AAT