"Although disease and suffering in animals are unpleasant and, perhaps, regrettable, biologists recognize that conservation is engaged in the protection of the integrity and continuity of natural processes, not the welfare of individuals. At the population level, the important processes are ultimately genetic and evolutionary because these maintain the potential for continued existence. Evolution, as it occurs in nature, could not proceed without the suffering inseparable from hunger, disease, and predation. For this reason, biologists often overcome their emotional identification with individual victims. For example, the biologist sees the abandoned fledgling or the wounded rabbit as part of the process of natural selection and is not deceived that "rescuing" sick, abandoned, or maimed individuals is serving the species or the cause of conservation. (Salvaging a debilitated individual from a very small population would be an exception, assuming it might eventually contribute to the gene pool.) Therefore, the ethical imperative to conserve species diversity is distinct from any societal norms about the value or the welfare of individual animals or plants. This does not in any way detract from ethical systems that provide behavioral guidance for humans on appropriate relationships with individuals from other species, especially when the callous behavior of humans causes animals to suffer unnecessarily. Conservation and animal welfare, however, are conceptually distinct, and they should remain politically separate."