There are numerous theories regarding how to ground the moral worth of human beings. What of other living things? Do some have greater value than others? Is a domestic turkey bred and raised to be eaten by humans of comparable worth and value to a dolphin or a pygmy bonobo? If we say "Yes." then where do we draw the line? Are single-celled organisms intrinsically valuable? What about plants and trees? Must a living thing be an animal, or is the fact that it is living sufficient to confer moral worth upon it? What of lakes, rivers, streams, and oceans? How about mountains, deserts, canyons, and grasslands? Do they have moral worth? If we claim that they do, then how do we underwrite that value? Where does it reside?
Can we conceive of a way of investing these things with value which has some sort of objectivity to it? Are there standards which are not humanly defined by which we could say that one of these entities has moral worth? If so, how would we as humans be able to recognize and respond to such standards?