I reject the premise: the "question" isn't begged at all. I have never once felt the need to ask what is our "purpose".
Or rather, the "purpose" of our species is exactly the same as the "purpose" of any other form of matter generalçy speaking, and of living organisms if you want to be more specific. There is no special "purpose" beyond the inevitable unfolding of the laws of physics, including those that apply to the self-replicating chemical compounds that constitute "life".
