Further to Photosynthesis from 3.8 billion years ago? (This is despite the complexities of photosynthesis?), another recent study wonders whether early Earth life forms were starved for sulfate:
The findings paint a new portrait of our planet’s early biosphere and primitive marine life. Organisms require sulfur as a nutrient, and it plays a central role in regulating atmospheric chemistry and global climate.
Previous research has suggested that Archean sulfate levels were as low as 200 micromolar — concentrations at which sulfur would still have been abundantly available to early marine life.
The new results indicate levels were likely less than 2.5 micromolar, thousands of times lower than today.
Using models informed by sulfate isotope fractionation in Lake Matano, they established a new calibration for sulfate isotope fractionation that is extensible to the Earth’s oceans throughout history. The researchers then reconstructed Archean seawater sulfate concentrations using these models and an exhaustive compilation of sulfur isotope data from Archean sedimentary rocks.
Sounds interesting. See also: Maybe if we throw enough models at the origin of life… some of them will stick? Lotta models there.
Follow UD News at Twitter!