Drosophila courtship – the male (bottom) produces a song with his wing to seduce the female.
“…beauty is the by-product. The main business is sex and death.” – Sam Llewelyn
Living things on earth today are the descendants of individuals that were good at reproducing and avoiding death. In fact the fittest imaginable organism – a Darwinian Demon – should reproduce extremely rapidly and forever. But Darwinian Demons don’t exist. Instead the creatures inhabiting our planet are of limited reproductive ability and finite lifespan. Moreover, we often find that organisms that mate and reproduce at high rates tend to be short lived. But why should sex, reproduction and ageing be linked like this? And why, if sex and reproduction leads to death, do some organisms have more many mates than others?
The answers lie in the facts that firstly, selection doesn’t act on the survival of individuals per se, it only acts to maximise the spread of genes via reproduction, and secondly males and females have very different ways of maximising their reproductive success. Consequently there are a bewildering array of adaptations that contribute to the ability of males and females to ensure the transmission of their genetic material to future generations, even though some of these adaptations may, as a side-effect, lead to senescence and death. By integrating molecular mechanisms into evolutionary biology, our lab tries to to understand how the genes and proteins carried by individuals result in success or failure in the arena of sex and survival. We mainly use insects for our work, in particular the fruit fly, Drosophila melanogaster, a species for which we have enormous power to manipulate genes and measure Darwinian fitness.