L-systems generate weevils, pizza toppings, and matriarchal lineages

The Fibonacci sequence is so-called because in Western mathematics is first appears in connection with a problem from Fibonacci's 1202 book Liber Abaci. Fibonacci asks us to consider a rabbit farm where a pair of baby rabits grows to adulthood in one month, and an adult pair of rabbits gives birth to a new pair of babies after a month. Representing an adult pair with a and a baby pair with b, we could write this as: b → a a → ab Starting with one pair of baby rabbits, and performing the indicated substitutions month by month, we get: b a ab aba abaab abaababa abaababaabaab abaababaabaababaababa abaababaabaababaababaabaababaabaab abaababaabaababaababaabaababaabaababaababaabaababaababa … The total number of symbols (and pairs of rabbits) each month gives us the Fibonacci sequence, as does the total number of as, or the total number of bs, in each line. A structure like this one, in which there are symbols, in this case a and b, that are repeatedly replaced with strings of symbols, is…