Molecular fossils extracted from rocks 635 million years It’s not the earliest evidence of animal existence, but common algae, according to new research from a decade-long controversy.
Researchers at the Australian National University (ANU), Max Planck Institute and California Institute of Technology say the results, published in Nature, ecology and evolution, is essential to our understanding of evolution.
“It brings the oldest animal evidence back nearly 100 million years back to today,” said Dr. Lennart van Maldegem of ANU, co-author of the study.
“We were able to show that some molecules of common algae can be changed by geological processeswhich leads to the formation of molecules that cannot be distinguished from those produced by animals such as sponges, ”he adds.
Professor Jochen Brox, also at ANU, said the mystery of when our most ancient animal ancestors emerged and became abundant in the oceans has puzzled paleontologists for over a century.
“Ten years ago, scientists have discovered molecular fossils of an animal steroid on rocks that were once at the bottom of an ancient sea in the Middle East, said Professor Brox.
“The big question was, how could these sponges be so numerous, covering most of the seabed around the world without leaving fossilized bodies?”
Doctor Ilya Bobrovsky, the lead author of another study, said the researchers had “unraveled this mystery.” “While it is true that sponges are the only living organism that can produce these steroids, chemical processes can mimic biology and convert the common and numerous sterols in algae into sterols of ‘animal origin,’” he said.
“These molecules can be created in the laboratory by simulating geological weather and temperature, but we also show that such processes took place in ancient rocks.”