Post by Joe Botting on Jul 20, 2005 16:53:24 GMT -5
We're going even further back in time, now. At least, potentially. If you think animals are varied, they've got nothing on bacteria. Even the number of different types of metabolism they have is enormous, from aerobic, methanogenic, sulphidic, chemosynthetic... They live at temperatures from -50C to +130C, and practically every environment down to several kilometers down in the crust, between the pore spaces of the rock.
Now researchers have found another way that bacteria can make a living: photosynthesis at the bottom of the ocean! (http://www.sciencenews.org/articles/20050625/fob5.asp)
It has long been suspected that photosynthesis is an accidental by-product of some other function that chlorophyll once had, probably related to the detection (and use?) of heat. It's an amazingly successful accident, though: anywhere there's a little bit of water and a drop of sunlight, and you'll find something photosynthesising. Up to now, the photic limit was about 130 m down in clear water, the last point at which there is enough light to make the algae viable. Now, photosynthesis has been found at the bottom of the Pacific, where the amount of sunlight is limited to one or two very lost photons. The source of light? The glow of rocks and water at the hydrothermal vents ('black smokers'). Yes, I know, it's daft. Honestly, we couldn't make it up.
What this means for the early evolution of life is that photosynthesis could indeed have originated at hydrothermal vents, before a stray bacterium got wafted up into the ocean waves... and the rest is prehistory, as they say. It adds another theoretical link in the discussions over the course of early life, and I'm going to hedge my bets and say that hydrothermal vents are fast becoming a front-runner for the cradle of life itself...
Poetic, eh? Don't worry. It won't last. It's all slime, really, after all.
Now researchers have found another way that bacteria can make a living: photosynthesis at the bottom of the ocean! (http://www.sciencenews.org/articles/20050625/fob5.asp)
It has long been suspected that photosynthesis is an accidental by-product of some other function that chlorophyll once had, probably related to the detection (and use?) of heat. It's an amazingly successful accident, though: anywhere there's a little bit of water and a drop of sunlight, and you'll find something photosynthesising. Up to now, the photic limit was about 130 m down in clear water, the last point at which there is enough light to make the algae viable. Now, photosynthesis has been found at the bottom of the Pacific, where the amount of sunlight is limited to one or two very lost photons. The source of light? The glow of rocks and water at the hydrothermal vents ('black smokers'). Yes, I know, it's daft. Honestly, we couldn't make it up.
What this means for the early evolution of life is that photosynthesis could indeed have originated at hydrothermal vents, before a stray bacterium got wafted up into the ocean waves... and the rest is prehistory, as they say. It adds another theoretical link in the discussions over the course of early life, and I'm going to hedge my bets and say that hydrothermal vents are fast becoming a front-runner for the cradle of life itself...
Poetic, eh? Don't worry. It won't last. It's all slime, really, after all.