A chapter on welfare biology by the moral philosophers Catia Faria and Oscar Horta is included in the 2019 book The Routledge Handbook of Animal Ethics. In the chapter, they argue that welfare biology could be partially developed from animal welfare science, but its focus would be broader because it wouldn't only focus on studying animals under human control. Faria and Horta also assert that welfare biology could be developed from ecology, with a focus on how the well-being of sentient individuals is affected by their environments.