Another edition of, "I was told there would be no math:"

An article on Wednesday about the arrival of the 17-year cicada in the eastern United States omitted a word in a quotation from Gene Kritsky, a professor of biology. He said the 17-year cicada had no competition from other periodic species because 17 is a prime number — divisible only by itself and 1 — making it impossible for the life cycles of other species to synchronize in any years. He said, "So no other species have evolved in synchrony with cicadas."

Huh?