I'm guessing they're 13 and 17 year cicadas because that's how long it takes to develop.
That's a tautology. "A baby takes 9 months to be born because that's how long it takes to develop." Well, yes, but the question becomes, why does it take that amount of time to develop? Were there direct selection pressures acting on that length of time, or is that length of time mostly a function of other variables which are acted on directly by selection pressure?
That's a tautology. "A baby takes 9 months to be born because that's how long it takes to develop." Well, yes, but the question becomes, why does it take that amount of time to develop? Were there direct selection pressures acting on that length of time, or is that length of time mostly a function of other variables which are acted on directly by selection pressure?