Chlorophyll VS. Retinal
Chlorophyll became more efficient
Chlorophyll, the photosynthetic pigment of plants, absorbs mainly blue and red wavelengths from the Sun and reflects green ones, giving plants their leafy color.
At one point, chlorophyll and retinal based organisms existed at the same time, yet chlorophyll became more efficient than retinal because it made better use of absorbed light.
This is because although chlorophyll uses an inefficient part of the light spectrum it is actually more efficient at releasing energy from it than retinal is.
Evidence for early existence of Retinal
Retinal, found in the plum-colored membrane of a photosynthetic microbe called halo bacteria, absorbs green light and reflects back red and violet light, the combination of which appears purple. Shil DasSarma, a microbial geneticist at the University of Maryland, has found that retinal has a much simpler structure than chlorophyll and therefore would be able to survive in a low oxygen environment of early earth. Scientists have also discovered that the process for creating retinal is very similar to that of a fatty acid,which is an important element in the development of cells. Lastly, halo bacteria, a microbe alive today that uses retinal, is not a bacterium at all. It belongs to
a group of organisms called archaea, whose lineage stretches back to a time before Earth had an oxygen atmosphere.
Chlorophyll, the photosynthetic pigment of plants, absorbs mainly blue and red wavelengths from the Sun and reflects green ones, giving plants their leafy color.
At one point, chlorophyll and retinal based organisms existed at the same time, yet chlorophyll became more efficient than retinal because it made better use of absorbed light.
This is because although chlorophyll uses an inefficient part of the light spectrum it is actually more efficient at releasing energy from it than retinal is.
Evidence for early existence of Retinal
Retinal, found in the plum-colored membrane of a photosynthetic microbe called halo bacteria, absorbs green light and reflects back red and violet light, the combination of which appears purple. Shil DasSarma, a microbial geneticist at the University of Maryland, has found that retinal has a much simpler structure than chlorophyll and therefore would be able to survive in a low oxygen environment of early earth. Scientists have also discovered that the process for creating retinal is very similar to that of a fatty acid,which is an important element in the development of cells. Lastly, halo bacteria, a microbe alive today that uses retinal, is not a bacterium at all. It belongs to
a group of organisms called archaea, whose lineage stretches back to a time before Earth had an oxygen atmosphere.