Sentence:  The goal isn't simply to generate offspring, but rather to produce "successful" offspring, and if you're a mouse, success is best achieved by living fast, loving hard, and dying young ... If you're an elephant, success requires a very different reproductive style. And if you're a human being, you are more elephantine than <WSD>muscine</WSD>. 
Meaning of the word marked with <WSD> tags:  Murine; of, pertaining to, resembling, or being a mouse.