Shipman suggests that the animal connection was prompted by the invention of stone tools 2.6-million years ago. "Having sharp tools transformed wimpy human ancestors into effective predators who left many cut marks on the fossilized bones of their prey," Shipman said. Becoming a predator also put our ancestors into direct competition with other carnivores for carcasses and prey. As Shipman explains, the human ancestors who learned to observe and understand the behavior of potential prey obtained more meat. "Those who also focused on the behavior of potential competitors reaped a double evolutionary advantage for natural selection," she said.Really? What did we learn from keeping parrots or rabbits that helped us hunt better? And I should point out that while we certainly may have been keeping pets for millions of years, the earliest evidence pertains to dogs and goes back only 32,000 years.
Pet keeping is quite striking, but does it have to have a purpose? I think it could equally well be an unselected product of other changes related to life among a hunter-gathering band: curiosity, the habit of caring for little animals that aren't our own offspring, the intelligence to figure out how to care for and control members of other species, the desire for validating affection without the need to negotiate the complexities of human society.
Not everything we do has an evolutionary purpose.