on a slightly different topic, but still related to prolonged slumps, these clever fellows have unearthed the history of slump busting,
New scientific findings indicate that ancestral humans split from chimpanzee forebears more recently than previously thought and raise the possibility that the two nascent species hybridized before making their final separation. ...
Under the hybridization scenario, the ancestors of humans and chimpanzees split from their common ancestor. After that initial separation, however, members of the two new species interbred an unknown number of times.
The Link