The current consensus among biologists and archaeologists is that the dating of first domestication is indeterminate.[4][21] There is conclusive evidence that dogs genetically diverged from their wolf ancestors at least 15,000 years ago,[22][23][24] but some believe domestication to have occurred earlier.[4] It is not known whether humans domesticated the wolf as such to initiate dog's divergence from its ancestors, or whether dog's evolutionary path had already taken a different course prior to domestication. The latter view has gained proponents, such as biologists Raymond and Lorna Coppinger;[5] they theorize that some wolves gathered around the campsites of the paleolithical man to scavenge refuse, and that associated evolutionary pressure developed that favored those who were less frightened by, and keener in approaching, humans. The bulk of the scientific evidence for the evolution of the domestic dog stems from archaeological findings and mitochondrial DNA studies. The divergence date of roughly 15000 years ago is based in part on archaeological evidence that demonstrates that the domestication of dogs occurred more than 15,000 years ago,[4][21] and some genetic evidence indicates that the domestication of dogs from their wolf ancestors began in the late Upper Paleolithic close to the Pleistocene/Holocene boundary, between 17,000 and 14,000 years ago.