Only if you think that the distinction between life and death, between survival and extinction is arbitrary. Saying a species is "successful" just means that it has been able to survive over time. Species that are best able to survive are the ones that are best able to adapt to their environment. This is fitness. As Steven Pinker puts it: "Well into my procreating years I am, so far voluntarily childless, having squandered my biological resources reading and writing, doing research, helping out friends and students, and jogging around incircles, ignoring the solemn imperative to spread my genes. By darwinian standards I am a horrible mistake, a pathetic loser, not one iota less than if I were a member of Queer Nation. But I am happy to be that way, and if genes don't like it, they can go jump in the lake." How The Mind Works p52.
Sam Pawlett