News Chemistry

Oldest evidence for complex life in doubt

Chemical fossils may have migrated into rock after sediments formed

By Sid Perkins

- More than 2 years ago

Chemical biomarkers in ancient Australian rocks, once thought to be the oldest known evidence of complex life on Earth, may have infiltrated long after the sediments were laid down, new analyses suggest.

Chemical biomarkers in 2.7-billion-year-old Australian rocks, once thought to be the oldest known evidence of complex life on Earth, may have infiltrated long after the sediments were laid down, new analyses suggest.
The isotopic composition of this pyrobitumen, one form in which carbon is preserved in rock, suggests that one of the earliest known markers for complex life may be younger than thought.