As many of us dread another visit by the exterminator to zap those blasted termites, most of us thank to popular pest control commercials perceive the battle to be between exterminator and pest. Well, when it comes to serious battles with lots of drama, termite vs. termite is far more interesting and educational.
In fact a new study on termites may have the answer for an evolutionary question posed by Charles Darwin nearly 150 years ago: How does natural selection support insect “worker” and “soldier” offspring who never reproduce, find mates or start their own colonies?
“This question about the evolution of social behavior among insects really intrigued me,” said lead researcher and University of Maryland evolutionary biologist Barbara Thorne, who has spent nearly 30 years pursuing the answer.
Basically, natural selection argues that small biological changes yield greater chances of survival and successful reproduction. However, that notion or process does hold water with regard to the evolution of social insects, especially when they live in colonies consisting of over a million non-reproductive members. Apparently, the answer may be because the workers and soldiers stay home.
“Social insects are extremely successful and dominant in many different habitats all over the world, yet we don’t understand how this thriving but complex colony structure evolved. It’s why I got involved in these studies when I was a young graduate student,” Thorne said.
Her team’s research shows that when two neighboring termite families within the same log meet, they battle, often leading to the deaths of one or both families’ kings and queens. This paves the way for replacement “junior” kings and queens to develop from either or both colonies’ worker offspring. In other words, sterile termites can become reproducers when their parents are killed becoming the main progenitors for the colony.
“These findings demonstrate how ecological factors could have promoted the evolution of social organization by accelerating and enhancing direct fitness opportunities of helper offspring, rendering relatedness favoring kin selection less critical,” Thorne said.