Of all the puzzles in xenobiology, perhaps the most remarkable is the existence of large-scale (but very imperfect) social cooperation among the East African Plains Ape of Sol III. Elsewhere on Sol III, large-scale social cooperation is limited to the social insects, in which each (sterile) worker is genetically identical to the (fertile) queen, and thus through standard Darwinian mechanisms treats the queen's children as if they were her own children and sisters. Aside from these social insects in which large-scale cooperative behavior is evolutionarily stable by virtue of genetic identity, cooperation on Sol III is limited to herds or packs of at most 100 individuals--and even there the pack must be closely genetically related.
By contrast, one million East African Plains Apes are involved in the complex social division of labor that we have termed "Toyota"--and those one million engage in complicated acts of social reciprocity with at least twenty times their number of outsiders who are not engaged in the "Toyota" social network.
How can this be?
We have recovered and are analyzing a textual artifact that we hope will provide the answer:
Paul Seabright (2004), In the Company of Strangers: A Natural History of Economic Life (Princeton: Princeton University Press: 0691118213).