Was life on the early Earth purple?
Tuesday, October 16, 2018 - 07:10
in Biology & Nature
Early life forms on Earth may have been able to generate metabolic energy from sunlight using a purple-pigmented molecule called retinal that possibly predates the evolution of chlorophyll and photosynthesis. If retinal has evolved on other worlds, it could create a a distinctive biosignature as it absorbs green light in the same way that vegetation on Earth absorbs red and blue light.