Conclusive evidence for ‘Selfish Gene’ theory found.

I have to admit, I never really got evolution in any sophisticated way before I read Richard Dawkins‘ seminal 1976 book, The Selfish Gene.  Dawkins illustrated the foundation of a paradigm shift in evolutionary biology away from group selection or kin selection and toward the gene as the unit of selection driving evolution.  That shift shaped the whole of modern biology, and selfish gene theory is the predominant model used by scientists today, with notable exceptions such as E. O. Wilson.  Before I read The Selfish Gene, I knew that evolution by natural selection made accurate predictions about the observable biological world, but the nuances of its mechanism—gene selection—were over my head.  It wasn’t elegantly taught in my high school biology classes, if it was even taught at all.  I recall it being discussed in more depth in my undergrad life sciences courses at the University of Maryland, but that was, unfortunately, around the time I was tuning out (temporarily) academic ambition.  It was after reading Dawkins’ The God Delusion that I was so impressed with his writing tone and style I purchased The Selfish Gene.  And science, am I ever glad I did.  Each chapter seemed to evoke another Eureka! moment, where the dense veil of complexity was lifted from life and I felt a renewed calling toward the study of biology (my first declared major in college).

That said, you can understand why I am so excited about this: next month, the journal Genetics will publish research findings by University of Western Ontario biologist Graham Thompson, and Peter Oxley and Benjamin Oldroyd of the University of Sydney in Australia, who managed to isolate part of the honeybee genome that is responsible for reproductive altruism.¹  (Full text of the article is available now).²  As you may know, female worker honeybees [order Hymenoptera] are sterile.  In a honeybee colony, the queen is the only reproductively active female.  Sex determination for honeybees is haplodiploid, meaning that the queen may lay fertilized female eggs (with two sets of chromosomes, or diploid), or unfertilized male eggs (with one set of chromosomes, or haploid).  The queen, having stored sperm in a spermatheca during her numerous mating flights (what a slut!), can choose how many male and female offspring to produce.  Although all her female offspring possess the genetic potential to be queens, the overwhelming majority of them will remain sterile workers, toiling away to feed and groom the queen as she becomes a huge sibling factory.  Their ovaries will remain inactive, and they will devote their lives to the queen.  Occasionally, ‘anarchist’ colonies of honeybees are found, in which a small proportion of females besides the queen activate their ovaries and begin to reproduce.  Thompson, Oxley, and Oldroyd have at last discovered what appears to be conclusive, material evidence that the selfish gene is real!  Specifically, what they have done is identified four quantitative trait loci (QTLs) that account for 25% of the phenotypic variance in ovary activation.  These are regions of the honeybee genome that are almost certain to contain genes responsible for the selfish ‘cheating’ behavior found in the ‘anarchist’ colonies.  Although this does not mean that the actual genes have been defined, it does mean that they are now very close to doing so.  So the theoretical assumption underpinning modern biology, although quite strong on its own, finally has physical, molecular evidence to support it.  This sort of thing makes me a bit weak in the knees, so please forgive my ebullience.

Oh, and in case you couldn’t tell, I <3 honeybees.

¹ Western News - The University of Western Ontario

² Genetics Volume 179, No. 3, July 2008.  Four quantitative trait loci that influence worker sterility in the honeybee (Apis mellifera), by Peter R. Oxley, Graham J. Thompson, and Benjamin P. Oldroyd.

Ninja bears?

I know I haven’t posted recently, and thus have really not kept up with my new years resolution to post at least once a week. But, I probably cursed this blog with that resolution. So, in an attempt to humble my high-and-mighty scientific ambitions and set the bar lower to allow more frequent updates, I present you with:

NINJA BEARS!

Photographer unknown.