Scientists have discovered a microorganism they believe could be the missing evolutionary link between ancient single-celled creatures and more complex species, such as plants and animals.
The single-celled organism, named Lokiarchaeota, was found deep under the Arctic Ocean floor.
All life on Earth belongs to one of two categories: single-celled archaea and bacteria - together known as prokaryotes - and eukaryotes, which comprises everything else.
"Prokaryotes have small, simple cells without nuclei," while eukaryotes "have large, complex cells with nuclei and a degree of internal organisation, including a cytoskeleton", scientists at Uppsala University in Sweden said in a statement accompanying their research, which was published yesterday in journal Nature.
The problem is, there has never been an example of an obvious evolutionary link between the two groups.
"Eukaryotic cells are so different from prokaryotic cells that understanding how the former evolved from the latter has been puzzling," said lead author of the study, Thijs Ettema.
Lokiarchaeota however, while belonging to the archaea category, has genetic "code for proteins only otherwise found in eukaryotes", suggesting a common ancestor between Lokiarchaeota and eukaryotes could have served as a link between the two.
"These genetic features may have provided the first ancestral eukaryotes with a 'starter kit' to support the increase of cellular complexity that is characteristic for eukaryotes today," scientists said.
Lokiarchaeota was named for Loki, a Norse god. It was found near a group of hydrothermal vents between Greenland and Norway known as Loki's Castle.
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source: newshub archive
