Ancestral populations perform better in a novel environment: domestication of Mediterranean fruit fly populations from five global regions

Geographically isolated populations of a species may differ in several aspects of life history, morphology, behaviour and genetic structure as a result of adaptation in ecologically diverse habitats. We used a global invasive species, the Mediterranean fruit fly (medfly), to investigate whether adaptation to a novel environment differs among geographically isolated populations that vary in major life history components, such as life span and reproduction. We used wild populations from five global regions (Kenya, Hawaii, Guatemala, Portugal and Greece). Adult demographic traits were monitored in the F-2, F-5, F-7 and F-9 generations in captivity. Although domestication in constant laboratory conditions had a different effect on the mortality and reproductive rates of the different populations, a general trend of decreasing life span and age of first reproduction was observed for most medfly populations tested. However, taking into account the longevity of both sexes, age-specific reproductive schedules and average reproductive rates, we found that the ancestral Kenyan population kept the above life history traits stable during domestication compared with the other populations tested. These findings provide important insights into the life history evolution of this model species, and suggest that ancestral medfly populations perform better than the derived, invasive ones in a novel environment. (C) 2011 The Linnean Society of London, Biological Journal of the Linnean Society, 2011, 102, 334-345.