"What do we consider disvaluable and valuable in our own lives? Some people say negative and positive experiences, others say thwarted and satisfied preferences, others say a list of things such as ignorance and knowledge, meaningless or meaningful relations, pain and pleasure, etc. All these different things require that we're sentient. We don't consider that what is valuable in our lives is just being the members of a certain species or living in some ecosystem as such. Abstract entities such as species and ecosystems cannot feel pain and other affections, and therefore don't have interests, while sentient beings do. This is why we should be concerned with what happens to sentient individuals, rather than abstract groups."