Peter Singer
Notes
Peter Singer (b. 1946), Australian moral philosopher and utilitarian, best known for Animal Liberation (1975), which argued that the capacity to suffer, not species membership, is what gives a being's interests moral weight, and coined the modern use of "speciesism". His essay "Famine, Affluence, and Morality" (1972) is the starting point of the effective altruism movement. He appears here because his argument about animals is the one I cannot answer.
Wikipedia: https://en.wikipedia.org/wiki/Peter_Singer