Fish species evolved with mountain ranges: New Zealand-led study

New Zealand researchers said Tuesday they have discovered a rare example of how natural changes to the landscape can directly influence evolution.

The growth of mountain ranges on New Zealand's South Island directly influenced the evolution of different freshwater fish species in the region, according to the University of Otago-led research.

The study provided an example of how natural changes in the Earth's landscape and topography could help shape and increase local biodiversity, said Professor Dave Craw.

Mountain ranges formed when tectonic plates collide, and the uplift of a new range could separate biological populations and eventually lead to the creation of new species, Craw said in a statement.

The New Zealand researchers joined colleagues at Australia's University of Tasmania to use a numerical model to reconstruct the topographic evolution of the South Island over the past 25 million years.

They showed the island's landscape developed in six main tectonic zones, each with distinct river drainage catchments.

They then analyzed more than 1,000 specimens of freshwater fish populations from more than 400 area to show that the fish DNA sequences had diverged over time in tandem with the growth of the mountains.

"By modelling the mountain-building processes, we can really start to understand how the changing landscape has shaped biological processes," Craw said.

"New Zealand's geographic isolation and dynamic geology make it the perfect place for understanding evolution."