As glaciers around the world are melting back, what are they releasing? Old microbes and even older DNA fragments, as it turns out.
Ice 100,000 to 8,000,000 years old was cut from Antarctic glaciers and carefully melted under sterile conditions. The result: healthy, fast-multiplying microbes, expecially from the younger samples. Scientists found there was a "half-life" of about 1.1 million years for DNA of frozen microbes: about half of it disappears in that time. So some samples showed, not viable animals, but fragments, which themselves could have unknown impacts if released into the aquasphere.