One could argue that law is used to preserve our own species. Almost all living species put their own kind first. This is a function of evolution; nothing metaphysical. Everybody "thinks" their own "team" is superior. Superiority can be biased and subjective.
Law it's not biased a priori towards humans.
If a hypothetical strong AI could pass the Turing test our Law would accept it.
Actually there are political groups that want to give legal status to some primates. But always failing...