Where can you find nearly double the concentration of viruses than normally found anywhere on Earth? Antarctic freshwater lakes. Fancy that.
Scientific American writes,
“Researchers braved frigid temperatures to collect water samples from Lake Limnopolar, located on Livingston Island near the Antarctic Peninsula, and sequenced the genomes of the collected species. The new genetic study reveals some 10,000 species of viruses from a dozen families.”
Apparently the unusually high viral diversity is due to the lower diversity of other organisms in the lakes. That seems to make sense … given that it IS Antarctica and all. MSNBC Technology and Science said,
“At first glance, Antarctica's freshwater lakes don't seem very hospitable to life. They remain frozen for a good nine months out of the year, and they contain very few nutrients. Some of these lakes have little animal life and are dominated by microorganisms, including algae, bacteria, protozoans and viruses.”
But what is causing these viruses to thrive so well?
They feed off the lake’s eukaryotes to get through the low-nutrient and dim-lit months of the year. When the ice melts in the peak of the Antarctic summer (which is in December), many of the single-stranded DNA viruses actually change into double-stranded ones!
Antonio Alcami of the Spanish Research Council and co-author of the study, told Live Science, “"It looks like a completely different lake in summer." The researches suspect that the virus transformations may be due to an increase in algae during the summertime, which the larger viruses infect.
The scientists don’t yet know if the viruses are unique to Antarctica or if they can also be found in other parts of the world, but they hope the answer will help them conclude whether or not life evolved independently in Antarctica or if it has been introduced only more recently.