Fortunately the case for upholding the equality of human beings does not depend on equality of intelligence, moral capacity, physical strength, or any other matters of fact of this kind. Equality is a moral ideal, not a simple assertion of fact. There is no logically compelling reason for assuming that a factual difference in ability between two people justifies any difference in the amount of consideration we give to satisfying their needs and interests. The principle of equality of human beings is not a description of an alleged actual equality: it is a prescription of how we should treat human beings.

~ Peter Singer (1946-07-06 age:71)

So the fact that antelope cannot do calculus is no excuse to mistreat them or steal their habitat.