"When placed in the extreme below-background levels of radiation, essentially zero radiation, growth was inhibited in both species. Both species also showed a measurable stress response, identifiable to specific genes in their DNA, when in the absence of radiation.
Amazingly, those responses reversed when the bacteria were transferred back and forth to the opposite environments. The experiment used reciprocal controls to verify that the physiological responses observed were due to the radiation treatment. By restoring background radiation levels to radiation-deprived cultures, the growth rate of both species increased and the culture cell density returned to that of the control after only 24 hours.
So, two species of bacteria from disparate taxonomies sensed and exhibited a physiological response to the absence of radiation, indicating that these low levels of radiation are a significant environmental cue. And the lack of radiation produced the substantial stress, not the presence of radiation."
Originally shared by David Strumfels
http://www.forbes.com/sites/jamesconca/2015/09/23/is-radiation-necessary-for-life/
http://www.forbes.com/sites/jamesconca/2015/09/23/is-radiation-necessary-for-life
I've come to this hypothesis before from a few angles. Like that telomeres shouldn't get toooooo broken down, but if they grow too well, cancer may result (from limited reading). Also that a new species of sharks has been classified and decided to be a result of the nuclear bombs sunk to the bottom of the ocean off North Carolina. We HAVE radiation so it seems natural that life evolving under those conditions is geared toward it.
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