Why should we treat people with any respect?
They’re just an “accident of evolution”, of no more value than monkeys or pigs or rats...
And that whole “think of others before yourself” is such a religious concept, and religion is just a crutch for the weak minded.
We are to respect our self and others for we were created in the image of God.
If we are just like the rodents, we are operating only on survival, and eating and mating. No joy. No wonder. No seeking for higher things, and no inventions, discoveries, cures, etc. Why bother. Man has choice, animals do not ... they are instinctive.
Your premise as stated is wholly wrong.