Given that all life is related in a giant family tree, how might this fact influence ethical considerations, especially with regard to our relationships with other species? Should we give greater...

Given that all life is related in a giant family tree, how might this fact influence ethical considerations, especially with regard to our relationships with other species? Should we give greater consideration to species closely related to us? How close is "close"? What criteria should we use-shared biological characteristics? the same branch of the family tree?