Biological changes among invasive species

Date:  April 8, 2019

Source:  University of Plymouth

A remote island in the Caribbean could offer clues as to how invasive species are able to colonise new territories and then thrive in them, a new study suggests.

Scientists from the University of Plymouth have recently completed extensive research into a lizard population on the Cayman Islands.

Up until the mid-1980s, there had never been a recorded sighting of the Maynard's Anole (Anolis maynardi) on Cayman Brac island despite it being less than 10km from its native territory, Little Cayman.

However, since the species was first discovered on Cayman Brac in 1987 -- in what is thought to have been a human-assisted colonisation -- its population has spread right across the 39km² island.

For this study, recent graduate Vaughn Bodden and Lecturer in Conservation Biology Dr Robert Puschendorf conducted a detailed analysis of the invasive species.

They wanted to assess whether individuals at the forefront of the invasion have developed distinct biological traits that are advantageous for dispersal, and compared their findings to animals in the area of first introduction and the native population on Little Cayman.

They discovered the Cayman Brac population has diverged morphologically from the native population, and within the invasive range there was trend of increasing forelimb length from the core to range edge areas. This ran contrary to the expected findings that longer hindlimbs would be the trait selected as a dispersal-related phenotype.

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