Caption:
"And so, as you enter the adult phase of your life, you will thank God that these past 17 years of being stuck in the ground and unable to move are finally over. … Congratulations, cicadas of ’94!”
No alt text
Caption:
"And so, as you enter the adult phase of your life, you will thank God that these past 17 years of being stuck in the ground and unable to move are finally over. … Congratulations, cicadas of ’94!”
No alt text
I’ve heard that this type of cicada lives underground for 13 or 17 years, which immediately jumps out as being two different prime numbers.
It seems odd at first that a species seems to know about prime numbers, but there is a natural explanation. If there are ones that emerge in non-prime intervals, they are more likely to emerge at the same time due to their common factors. So those ones would tend to emerge in greater numbers, making them easier for predators to specialize in.
But staying underground for long intervals in prime numbers of years makes it difficult for those predators, so the prime cicadas would have an evolutionary advantage.
It’s been borrowed into graphic design as the Cicada Principle:
https://lea.verou.me/blog/2020/07/the-cicada-principle-revisited-with-css-variables/
Looks like the original link is dead, but there’s a newer examination of it. If you have a repeating pattern, you can maximize variation while minimizing file size by using multiple sequences with different prime lengths