Building upon recent insights that morality evolves to secure fitness advantages of cooperation, we propose that conservation ethics is based in interest in cooperation between humans & non-humans

Value of species and the evolution of conservation ethics. Darragh Hare, Bernd Blossey, H. Kern Reeve. Human Behavior and Evolution Society 31st annual meeting. Boston 2019. http://tiny.cc/aa1w6y

Abstract: The theory of evolution by natural selection can help explain why people care about other species. Building upon recent insights that morality evolves to secure fitness advantages of cooperation, we propose that conservation ethics (moral beliefs, attitudes, intuitions and norms regarding other species) could be adaptations that support cooperation between humans and non-humans. We present eco-evolutionary cost–benefit models of conservation behaviors as interspecific cooperation (altruism towards members of other species). We find that an evolutionary rule identical in structure to Hamilton's rule (which explains altruistic behavior towards related conspecifics) can explain altruistic behavior towards members of other species. Natural selection will favor traits for selectively altering the success of members of other species (e.g. conserving them) in ways that maximize inclusive fitness return benefits. Conservation behaviors and the ethics that evolve to reinforce them will be sensitive to local ecological and socio-cultural conditions, so will assume different contours in different places. Difficulties accurately assessing costs and benefits provided by other species, time required to adapt to ecological and socio-cultural change and barriers to collective action could explain the apparent contradiction between the widespread existence of conservation ethics and patterns of biodiversity decline globally.
https://royalsocietypublishing.org/doi/full/10.1098/rsos.181038