Jun 23, 2017 - Energy & Environment

Scientists sequence century-old Antarctic bacteria

The Natural History Museum

Scientists have used bacterial samples collected on a 1902 expedition to Antarctica to study how climate change is affecting one of Earth's most extreme environments. They found the bacteria hadn't changed significantly over the century, suggesting they may be better adapted for climate change than microbes from other ecosystems.

Why it matters: As the climate and Antarctica continue to change, says study author Anne Jungblut, the more we know about the continent's past, the better we'll understand it's future. "These cyanobacteria are at the bottom of the food chain. They're photosynthetic and they create vibrant ecosystems with microscopic organisms in them. They're a keystone species."

The study: In 1902, Captain Robert Falcon Scott went farther into Antarctica than any had gone before. He brought home meticulous notes and biological samples of photosynthetic bacteria collected from meltwater lakes. Jungblut and her team used Scott's notes to retrace his expedition, and gather samples from the same areas he visited. They then compared the diversity and genes of the ancient and modern specimens.

What they found: Roughly the same bacteria were present in the 100-year-old samples and the modern ones, and their genes hadn't evolved much. Jungblut thinks the bacteria that live in Antarctica evolved for an environment of change, with subfreezing winter temperatures punctuated with periods of melt. These bacteria might be better adapted for climate change than microbes from less hardy ecosystems. Although they found more species in modern samples than in the historic samples, there appeared to be very little cross-contamination from non-Antarctic bacteria. The paper was published Wednesday in the journal Proceedings of the Royal Society B: Biological Sciences.

The big question: "A big question is how might Antarctic biodiversity be affected by environmental change," Jungblut tells Axios. In the 100 years since Scott's expedition, humans have made major changes to the Antarctic ecosystem. Temperatures have risen, a hole in the ozone layer has formed over the continent, and invasive species have hitched rides on tourists. But somehow, these bacteria have remained relatively unchanged.

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