Bees have long been making news. First there were killer bees, and now the bees are dying, and fast. A new study published in PLoS ONE has given us tantalizing clues into bees’ place in mass extinction events.
Small fragile insects don’t make for very good fossils so tracking insect populations and evolution have been extremely difficult. By studying the DNA of 230 tribes of carpenter bees worldwide and using fossil records to anchor time frames, researchers have been able, for the first time, to demonstrate an extinction of bees shortly after the K-T boundary. We have known for awhile that, in addition to the extinction of the majority of dinosaur species and other large reptile species during the K-T event, flowering plants suffered massive extinctions as well. The logical conclusion that follows is that bees must have suffered an extinction as well, but it has been merely an assumption until now.
By tracking the subtle changes in the genes between populations and tracing those changes back to ancestral tribes, the evolution of the tribes of bees can be followed. Somewhat like tracing river tributaries back to their source, the tribes’ points of divergence show a decline in the number of tribes shortly after the K-T boudary, meaning that large numbers died off leaving only a few genetic lineages to go on.
The timing of the extinction of the bees (shortly AFTER the K-T boundary) leads researchers to suspect that the bee extinction was in response to the loss of biodiversity not likely the cause of it, though they cannot be sure of that without more research. The loss of biodiversity due to global climate change, farming practices, and pollution as well as widespread insecticide and herbicide use are prime suspects in the decline of bee populations and this promising research will help us to understand the factors that are contributing to the extinction of bees we are currently seeing and what long-term effects it could have on ecology globally.
Edited and published by CB