Understanding the impact of competitive history on reproductive output under different temperature conditions in drosophila melanogaster

Abstract

What happens when a species is competing for food, shelter, space and other resources with another species? Interspecies competition is not just a temporary battle for resources, but is also responsible for shaping a species’ overall genetic makeup and physiological makeup, being passed down for generations to come. Eco-evolutionary dynamics regulate and determine the fate of species in a warming world, with global warming escalating at an alarming rate. In this study, I examined how competition in the presence of an invasive species affects the reproductive output of a resident species , and whether these effects are escalated under higher temperature conditions.. Populations of D. melanogaster were maintained at 23°C in two groups, experimental and control. The experimental group was exposed to competition with Zaprionus indianus, a pest and an invasive fruit fly, native to tropical Africa. The flies were subjected to competition for 4 generations, followed by removal of Z. indianus, and finally reared for 2 generations at different temperatures: 23°C and 28°C. The ecological trait being measured was fecundity, which had a direct impact on growth of the population and overall fitness of the species. The evolutionary response was the transgenerational effects of shared history with invader, changes in life-history traits and reduced fecundity even in the absence of the invader. Flies exposed to competition exhibited reduced fecunditythe overall reproductive output for control flies in the span of two weeks was 212±1.2 eggs whereas for experimental it was only 155±1.4 eggs Post-shared generations culturing at rearing high temperatures had a pronounced effect on the fecundity, with control flies reared at 23°C exhibiting the highest fecundity and experimental flies reared at 28°C exhibiting the lowest.