5 ms·

13 and 17 year cycles would mean these broods emerge at the same time only every 221 years! Thomas Jefferson was president the last time this happened.

• pkulak 3y ago
  I wonder if two prime numbers evolved as a way to make this as rare as possible.
  • d--b 3y ago
    There is a ton of literature about cicadas and prime numbers. Experts definitely lean towards the primes emerging from natural selection indeed.
  • chowells 3y ago
    Yes. Prime numbers come up in nature in a lot of cases when cyclic things evolve to minimize coincidence.
    • SpaceLawnmower 3y ago
      Are there other examples you're thinking of?
      • eindiran 3y ago
        Not OP, but Mautam in bamboo is another: https://en.wikipedia.org/wiki/Mautam https://en.wikipedia.org/wiki/Mautam Some other interesting links: - On bamboo in particular (semelparous and allochronic like cicadas): https://en.wikipedia.org/wiki/Bamboo_blossom https://en.wikipedia.org/wiki/Bamboo_blossom - https://en.wikipedia.org/wiki/Allochronic_speciation https://en.wikipedia.org/wiki/Allochronic_speciation - https://en.wikipedia.org/wiki/Semelparity_and_iteroparity https://en.wikipedia.org/wiki/Semelparity_and_iteroparity - On cicadas and their reproductive periods: https://en.wikipedia.org/wiki/Periodical_cicadas https://en.wikipedia.org/wiki/Periodical_cicadas - https://en.wikipedia.org/wiki/European_eel https://en.wikipedia.org/wiki/European_eel : same pattern, but using 2 and 3 as their primes.
  • deleted 3y ago
    [deleted]