science news: Purple Earth
penny April 11th, 2007
Scientists have found evidence that prior to being a predominantly green planet, Earth was purple!
Somewhat loose discussion:
This has something to do with how membranes of organisms absorb and reflect wavelengths of light from the sun’s rays. We all learned about chlorophyll in photosynthesis in grade school. Scientists are proposing the idea now that at one time, the Earth was riddled with organisms that absorbed green light and then reflected red+violet = purple light. But there existed some purple-absorbers who could not compete with the abundance of green-absorbers. To survive, the evolved with an ability to absorb purple, and reflect green. They somehow maintained survival, and eventually emerged victorious in dominating the environment.
So how useful is this information, aside from being strikingly adorable to purple-color lovers?
Well, for one thing, on our search for life in other planets, it means not always searching for the same observable things we see on Earth at present, like the dominance of color (green).
[If you want to look up more information about these news snippets I write about, I'll start putting some keywords to look out for]
Keywords: retinal, halobacteria, archael bacteria
