Differences don't. It is the cultures being outdated in today's contemporary moral standards. We know our ancestors didn't respect human and animal lives as much as we do. But those times are changing. Since the behavioral modernity started, we have come a long way to create today's international society whose moral compass has never been so high in global scale. This progress is what makes us human. We want today's protests for Eric Garner and George Floyd to make the racist cops in US think for a second before making a stupid move. And this is how we tell them, how fucked up they are in today's and tomorrow's standards. Life matters regardless of dna or philosophy.