Invasive species can evolve to suit new place

Researchers discover that the invasive population, which poses a threat to other plants and animals for all its destructive tendencies, might also embody a creative side.

Exotic species invading new territories threaten other plants and animals there, but for all their destructive tendencies, they might also embody a surprisingly 'creative' side, a new study has found.

Researchers discovered that an invasive population of the freshwater snail (M tuberculata) on Martinique island harbours tremendous genetic variation for key traits like fecundity, juvenile size and age at first reproduction - implying a potential for evolutionary change.

'It is widely believed that despite their tremendous ecological success, invasive populations, being founded by few individuals, lack genetic variability for important traits,' said French scientist Benoît Facon.

'Now, analysing a freshwater snail example, we document how a spectacular genetic diversity for key ecological traits can be accumulated in invasive populations.'

Researchers, writing in the March 11 issue of the journal Current Biology, show that the level of genetic variation in snails is among the highest ever recorded among animals for fundamental life-history traits.

M. tuberculata offered an 'unparalleled opportunity' to study the adaptive potential of invasives, because of its mixed reproductive system, meaning that the snails can reproduce both sexually and, more often, asexually.

Therefore, many individuals in a population are clones of one another, each clone representing a 'morph' with a distinctive shell. In Martinique, the researchers found seven such morphs: five of introduced origin, plus two produced by sexual crosses on the island.