Living World / Unusual Organisms
Discover Interview Tullis Onstott Went 2 Miles Down & Found Microbes That Live on Radiation
by Valerie Ross
From the July-August special issue of Discover; published online June 26, 2012
Quote: “This thing had everything. It could take nitrogen directly from its environment, something we did not expect subsurface organisms to do because it takes so much energy. But the real surprise was that it had genes for flagella, tails bacteria use to propel themselves, which basically means it could be swimming around in the environment. It had genes for gas vesicles, which means it can adjust its buoyancy in the environment. And it had genes for chemoreception, which tells us it’s sensing something. The genome is saying it’s a very adaptable organism, and it has the capability of moving around. The idea that organisms down there might be moving around and interacting with the environment—that was really surprising. The only tip-off from the genome that this is a subsurface organism is that it has no protection against oxygen. As soon as it hits air, it’s dead.”
My comment: The genes for chemoreception link this organism to olfaction and odor receptors that provide a clear evolutionary trail that can be followed from unicellular organisms to insects to humans. The obvious fact that this anaerobic organism can respond to them, links nutrient chemicals and pheromones to the epigenetic effects of the sensory environment on an organism that is not found at levels higher that two kilometers below the surface of the earth. It needs no oxygen, but it still must acquire nutrient chemicals, and the metabolism of nutrient chemicals to pheromones must control its reproduction as in every other species on (or underneath the surface of) this planet.