Recently, as John Biello tells it in “High temperature, low oxygen and permanent darkness are no problem for a previously unknown species of nematode,” (Scientific American, June 1, 2011), researchers found a nematode worm that lives more than a kilometre underground in South African gold mines. The species, called Halicephalobus mephisto, is believed to consume bacterial biofilms that themselves consume minerals.
As for how the nematodes found themselves more than a kilometer beneath the surface, no one knows for sure. “Nematodes have an uncanny ability to follow bacteria,” Borgonie notes, adding that the deep nematodes cultured in the lab preferred to eat subsurface bacteria rather than E. coli, like their counterparts nearer to the surface. “Another possibility is that mining activity does lower the water table and could ‘drag’ nematodes to the deep.”
University of Ghent nematologist Gaetan Borgonie also argues that life, even complex life, could be thriving beneath the surface of other worlds, like Mars, noting that doubt was “just such a mindset” that had prevented looking for complex life way down deep, in the past. One thing’s for sure, with exobiology (life on other planets), he’ll need to contend with more credulity than doubt, so a different skill set may be needed.