Scientists have discovered rare fossilized algae that tell more about an unknown period of evolution.
Geobiology graduate student Katie Maloney traveled to the mountains of the Yukon region of Canada to find microscopic fossils of early life. Even with detailed field plans, the chances of finding the desired fossils were slim. However, she was lucky and she found more than she bargained for.
Eukaryotic life, which has DNA in its nuclei, evolved over 2 billion years ago, with photosynthetic algae dominating at that time.
Geobiologists believe that algae evolved first in a freshwater environment on land and then moved to the oceans. But the timing of this evolutionary transition was unknown.
Fossils of several types of algae found by Maloney lived on the seabed about 950 million years ago. The authors of the work studied them and partially filled the evolutionary transition between algae and more complex life.
Maloney and colleagues used microscopy and geochemical techniques to confirm that the fossils were indeed early eukaryotes. They then detailed the cellular features of the samples to identify the species.