I really like this ScienceNOW account by Traci Watson of new work that has uncovered ancient DNA in deep-seafloor contexts: “Ancient DNA Found Hidden Below Sea Floor”. The article covers two studies, including one looking at 11,400-year-old DNA from the abyssal plain, another comparing more ancient and recent Black Sea seafloor samples. The latter study may help to redate the last time the Black Sea basin was flooded from the Mediterranean:
One type of marine fungus, for example, first appeared in the sediments roughly 9600 years agoexactly when some forms of freshwater plankton and a freshwater mussel vanish, the team reports this week in the Proceedings of the National Academy of Sciences. That suggests that marine waters started to invade the lake roughly 600 years earlier than thought. The team also found DNA from a form of marine alga in 9300-year-old sediments, though the alga doesnt show up in the fossil record until 2500 years ago, says molecular paleoecologist Marco Coolen of the Woods Hole Oceanographic Institution in Massachusetts and an author of the Black Sea paper.
What a neat project it will be, to explore seafloor DNA for unexpected inclusions. There’s a good reason to fund much more work here, given that the 11,400-year horizon where this is already practical is so near the Younger Dryas. We need a fleet of tiny autonomous vessels to find the interesting stuff – we can call them, “Glomar Venters”!