Did Life on Earth Start 3.7 BYA?

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SUMMARY

The discussion centers on the discovery of 3.7 billion-year-old rocks in Greenland, which may indicate early life on Earth. These rocks contain microscopic hematite tubes, potentially resembling biological structures found in modern hydrothermal vents. The prevailing hypothesis suggests that these early microbes thrived in an environment similar to mid-ocean vents, utilizing minerals as an energy source. However, the interpretation of these findings remains controversial, with ongoing debates regarding the origins of the hematite and the existence of life at that time.

PREREQUISITES
  • Understanding of geological time scales and the age of the Earth
  • Familiarity with hematite and its chemical properties (Fe2O3)
  • Knowledge of hydrothermal vent ecosystems and their role in early life
  • Basic concepts of microbial life and fossilization processes
NEXT STEPS
  • Research the geological significance of the 3.7 billion-year-old rocks in Greenland
  • Study the formation and characteristics of hematite in ancient environments
  • Explore the role of hydrothermal vents in the origin of life theories
  • Investigate the methods used to analyze ancient microbial life indicators
USEFUL FOR

Geologists, astrobiologists, and researchers interested in the origins of life on Earth, as well as anyone studying early microbial ecosystems and their geological contexts.

BillTre
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Since the planet is only 4.55 BY old, that might be considered a fast start.

Some people have found some rocks (3.7 BYA) in Greenland with what they think are indications of life (short article, a bit longer article). The indicators are primarily microscopic hematite tubes (some say, similar to tubes of biological origin found in more modern vents).

This is of course controversial.

Hematite is an oxidized form of iron (Fe2O3). The atmosphere at that time had little or no oxygen. They hypothesize that there were microbes living at the equivalent of mid-ocean vents, where hot water extracts minerals from the rocks that could provide an initial energy source for the first life forms (generally a popular explanation now for the first life forms).

I'm not clear on how the hematite becomes oxidized in these conditions.
Due to actions of the living bacteria (or whatever), or from a fossilization process after they die?
Is the oxygen coming from the dissolved minerals from the vents?
 
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BillTre said:
This is of course controversial.
Hematite is an oxidized form of iron (Fe2O3). The atmosphere at that time had little or no oxygen.
"Controversial?"
 
Bystander said:
"Controversial?"
Not everyone believes the rock structures are the result of living things.
 

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