Volcanoes sustained life during ice ages: Study

It is difficult to associate volcanoes with preserving life but that is true - heat from volcanoes helped cold Antarctica's plants and bugs survive ice ages, a study suggests.

"Volcanoes are generally seen as these big, explosive destroyers of life, but they might be important in promoting biodiversity," said lead author Ceridwen Fraser, a bio-geographer at Australian National University.

"This explains how life survived in Antarctica but we think this idea of geothermal refuges could also apply elsewhere," Fraser added.

Genetic and fossil evidence suggests that during the earth's last ice age 20,000 years ago, any Antarctic species that could cross the Southern Ocean fled, with penguins, seals and birds heading for warmer refuges.

"The only species that were left in Antarctica were those that could not get off," Fraser noted in the study published in the journal Proceedings of the National Academy of Sciences.

Genetic analyses also indicate that Antarctica's mosses, lichens and small invertebrates have been isolated from their relatives on other continents for millions of years.

Antarctica has at least 16 volcanoes that have erupted in the past 20,000 years.

Fraser and her team analysed more than 38,000 records of Antarctic species and discovered there are more moss, lichen and bug species close to Antarctica's volcanoes, and fewer farther away.

The pattern supports the idea that these species weathered the worst of the ice age at Antarctica's volcanoes, then gradually expanded their habitat range after the ice receded.