Interesting indeed but I was not able to find the source or any other reports on this monkey. Take it with a grain of salt. Scientists have recently published a report in PNAS that indicates that bipedal humans came from tree living apes. Could it be that our tree living ancestor had a mutation (like Natasha, the Israeli monkey) that allowed them to become bipedals. Being bipedal gave them benefit in the flat sub-Saharan Africa as they had vision much farther down and also could throw weapons such as spears better. This may have lead to the rise of the Homo? Of course this is a speculation but not entirely untrue.