This month a paper will be coming out in Nature Communications on the evolution of life histories. Benoit Facon is the corresponding author and the true leader of the research. We studied life-history evolution in colonies of Harmonia axyridis used in biological control of aphid pests and in invasive populations in North America and Europe. Relative to native populations, biological control populations have evolved a classic "fast" life history. They live fast and die young, literally. In contrast, invasive populations, which across many species are often assumed to follow a fast life history, are actually bet hedgers. They reproduce for a long, long, long time. They live long and prosper. So long, that their total fecundity is much higher than the native or biological control populations. It's such cool stuff to see how quickly and radically life histories evolve under different selective regimes, and it reveals much about those selective regimes.
The big mystery in my mind is how the heck do the invaders have higher fitness over all? Purging of deleterious recessives as we suggest in this Current Biology paper? How? That is the true mystery of invasive populations. What enables them, even when grown under common conditions, to achieve higher fitness?
The work was truly collaborative, and such a pleasure to be part of. I really have the best job in the world, and with a little luck, I'll get to go back to CBGP and have a whole new round of fun things to write about.