Deciphering the evolutionary history of microbial cyclic triterpenoids

Area of Science:

• Biogeochemistry
• Molecular Evolution
• Organic Geochemistry

Background:

• Cyclic triterpenoids are lipids with diverse roles in bacteria and eukaryotes.
• These molecules are preserved as biomarkers in sedimentary rocks, linking ancient microbes to Earth's history.
• Interpreting these biosignatures requires understanding their function and evolutionary pathways.

Purpose of the Study:

• To review potential evolutionary scenarios for cyclic triterpenoids.
• To examine recent genetic and biochemical studies providing evidence for these hypotheses.
• To link the geologic and molecular records of evolutionary history.

Main Methods:

• Review of existing literature on cyclic triterpenoid biosynthesis.
• Analysis of genetic and biochemical studies.
• Comparison of evolutionary hypotheses.

Main Results:

• Experimental evidence is emerging to distinguish between cyclic triterpenoid evolutionary scenarios.
• Understanding biosynthesis is crucial for interpreting ancient lipid biosignatures.
• Cyclic triterpenoids serve as a model linking geologic and molecular evolutionary records.

Conclusions:

• Further research on cyclic triterpenoids will enhance the interpretation of rock records.
• These lipids provide a compelling link between life's molecular history and Earth's geologic history.