The close kinship between humans, chimpanzees, gorillas, and orangutans is a central theme among participants in the debate about human treatment of the other apes, and it is a point emphasized by numerous contributors to the Great Ape Project. Richard Dawkins (1994) makes the point vivid by imagining a chain of daughters holding their mothers' hands starting on the African coast. Barely 300 miles inland would be an individual ancestor of both humans and chimpanzees. In a subsequent issue of Etica & Animali dedicated to the Great Ape Project, Maxine Sheets Johnstone (1996) chides philosophers for failing to recognize the importance of evolutionary history for a proper understanding of who we humans are, and where we have come from. What we need, she says, is "not a different conception of nonhuman animals ... but a different conception of ourselves." By delivering the message that we humans are apes, these authors and others seek to establish an empathetic bond between ourselves and our primate cousins. Empathy is probably the single most important determinant of actual human moral behavior, including the treatment of nonhuman animals. Given the applied nature of questions about the treatment of captive apes, it is entirely appropriate that the close relationship between us should be highlighted. But the role that relatedness should play in ethical theory is less clear (a point Dawkins acknowledges). To the extent that legal and regulatory challenges to keeping apes in captivity are likely to be based on principles of theory, it is important to understand what roles evolutionary theory can play in deriving such principles. In the ethical literature on animal rights, phylogenetic relatedness plays no direct role in determining the moral status of animals. Rather, various capacities such as the ability to experience pain, to suffer, to be an intentional agent, to participate intentionally in reciprocal social arrangements, and to be self aware have been put forward as the relevant factors for moral consideration...