Must EVERY member of a particular species (one kind of organism) be able to reproduce in order for the species to survive? Explain why or why not.

Not every member of a particular species (one kind of organism) must be able to reproduce in order for the species to survive. If you take homo sapiens for example (Humans) there are many males and females around the world who are sterile and unable to reproduce, yet you still see the human species flourishing.