October 4, 2010
Disappearing Glaciers Enhanced Biodiversity
Fossils reveal history of marine diversity in Chile
Biodiversity decreases towards the poles almost everywhere in the world, except along the South American Pacific coast. Investigating fossil clams and snails Steffen Kiel and Sven Nielsen at the Christian-Albrechts-Universität zu Kiel (CAU) could show that this unusual pattern originated at the end of the last ice age, 20.000 to 100.000 years ago. The retreating glaciers created a mosaic landscape of countless islands, bays and fiords in which new species developed rapidly "“ geologically speaking. The ancestors of the species survived the ice age in the warmer Chilean north.
The most species-rich groups of animals in the southern Chilean fiordlands are those inhabiting rocky shores. This is exactly the habitat that was created when the glacier retreated from their marine termini. "Molecular biologic investigations on phylogenetic relationships of these species show that they are geologically very young and descended from North Chilean ancestors. This agrees well with our results", says Sven Nielsen, who has been working on Chilean fossils for many years. "Charles Darwin, who was the first to discover fossils in this area during his voyage on the 'Beagle', would have been fascinated."
This research shows that for species conservation not only single, exceptional habitats need to be protected, but that a diversity of habitats needs be conserved to maintain a healthy biodiversity.
Image Caption: Fossil Chilean clams and snails. Photo/Copyright: Sven Nielsen
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