"[T]here are problems with using any of these definitions of biodiversity as a proxy for animal welfare. Biodiversity is essentially a measure of variety, even if different definitions of biodiversity involve different types of variety. Variety is not the same thing as flourishing. Among humans, this is very clearly true: I can work in a very diverse department (in terms of nationality, gender, philosophical style, etc.) where everyone is miserable. We see the same thing among nonhumans. A region with high biodiversity is full of lots of different kinds of individuals. They might be suffering; their lives might be barely worth living. But if they are alive, they count positively toward biodiversity. The only time welfare will affect biodiversity at all is when it affects either reproduction or mortality to such an extent that the relevant kind of variability in the population is diminished—for example, when a species goes extinct. However, significant effects on welfare happen to species members long before their species goes extinct. To care about biodiversity, then, is to care about the existence or presence of the kinds, not about the welfare of the individuals belonging to those kinds."