During past ice ages, when glaciers blanketed much of the globe, the steam and heat from active volcanoes helped sustain life. A new study, led by a team of researchers from Australia, analyzed the concentration of Antarctic plant and animal species in relation to volcanoes. In studying the thousands of records, compiled over many decades, the researchers were able to show that there are more species close to volcanoes and fewer farther away. The study was published in the journal Proceedings of the National Academy of Sciences. "Volcanic steam can melt large ice caves under the glaciers, and it can be tens of degrees warmer in there than outside," said Dr. Ceridwen Fraser, the lead author from the Australian National University in Canberra. "Caves and warm steam fields would have been great places for species to hang out during ice ages." Antarctica, the Earth's southernmost continent, hosts as many as 16 active volcanoes, still rumbling since the last ice age some 20,000 years ago. "Volcanoes are generally seen as these big, explosive destroyers of life, but they might be important in promoting biodiversity," Fraser told Live Science. "This explains how life survived in Antarctica, but we think this idea of geothermal refuges could also apply elsewhere."