homehome Home chatchat Notifications


Scientists find new microorganism that may shed light on evolution of complex cells

The discovery of a new microorganism may help bridge the knowledge gap between simple and complex cellular organisms, also shedding light on how complex cellular life came to be.

Mihai Andrei
May 7, 2015 @ 12:05 am

share Share

The discovery of a new microorganism may help bridge the knowledge gap between simple and complex cellular organisms, also shedding light on how complex cellular life came to be.

Image of a hydrothermal vent field along the Arctic Mid-Ocean Ridge, close to where 'Loki' was found in marine sediments. Credit: Centre for Geobiology (University of Bergen, Norway) by R.B. Pedersen

Image of a hydrothermal vent field along the Arctic Mid-Ocean Ridge, close to where ‘Loki’ was found in marine sediments.
Credit: Centre for Geobiology (University of Bergen, Norway) by R.B. Pedersen

For all of life’s complexity on Earth, we generally divide it in two classes: prokaryotes, and eukaryotes. Prokaryotes are the simplest life forms, with small, simple cells without nuclei; they comprise only of Bacteria and a group of creatures called Archaea. Meanwhile, eukaryotes have large, complex cells with nuclei and a degree of internal organisation, and they make up for all the other life on our planet – everything that’s macroscopic, and much of the microscopic too.

The problem is that the difference between these two groups is so huge that how the latter evolved from the former still remains a mystery; recent studies have indicated that eukaryotes evolved from Archaea, but the differences between the two are hard to account for, and biologists haven’t been able to find any organism to link the two – until now.

“The origin of the eukaryotic cell remains one of the most contentious puzzles in modern biology,” the authors wrote. “Recent studies have provided support for the emergence of the eukaryotic host cell from within the archaeal domain of life, but the identity and nature of the putative archaeal ancestor remain a subject of debate.”

Caption: Image of a hydrothermal vent field along the Arctic Mid-Ocean Ridge, close to where 'Loki' was found in marine sediments. Credit: Centre for Geobiology (University of Bergen, Norway) by R.B. Pedersen

Caption: Image of a hydrothermal vent field along the Arctic Mid-Ocean Ridge, close to where ‘Loki’ was found in marine sediments.
Credit: Centre for Geobiology (University of Bergen, Norway) by R.B. Pedersen

Thijs Ettema from the University of Uppsala and his team may have finally found that missing link – they discovered a new archaea from deep marine sediments that could be the closest prokaryote to eukaryotes. The newly discovered organism, Lokiarchaeota, has genes which code for proteins only otherwise found in eukaryotes, which researchers believe to be a ‘starter kit’ for developing more complex cells.

“Our results provide strong support for hypotheses in which the eukaryotic host evolved from a bona fide archaeon, and demonstrate that many components that underpin eukaryote-specific features were already present in that ancestor,” the scientists said.

It’s exactly the kind of thing researchers were hoping to find – something that explains how cells developed from simple to complex. The long standing puzzles of how and why these two groups separated two billion years ago may finally be uncovered.

“The identification of Lokiarchaeota so early in the history of this nascent field suggests that more-closely related archaeal relatives of eukaryotes will soon be discovered. The genomes and cellular features of these relatives may provide a more detailed picture of the most recent common ancestor of eukaryotes and archaea, and may help to resolve the timing of the innovations that are used to define eukaryotes.

share Share

A Dutch 17-Year-Old Forgot His Native Language After Knee Surgery and Spoke Only English Even Though He Had Never Used It Outside School

He experienced foreign language syndrome for about 24 hours, and remembered every single detail of the incident even after recovery.

Your Brain Hits a Metabolic Cliff at 43. Here’s What That Means

This is when brain aging quietly kicks in.

Scientists Just Found a Hidden Battery Life Killer and the Fix Is Shockingly Simple

A simple tweak could dramatically improve the lifespan of Li-ion batteries.

Westerners cheat AI agents while Japanese treat them with respect

Japan’s robots are redefining work, care, and education — with lessons for the world.

Scientists Turn to Smelly Frogs to Fight Superbugs: How Their Slime Might Be the Key to Our Next Antibiotics

Researchers engineer synthetic antibiotics from frog slime that kill deadly bacteria without harming humans.

This Popular Zero-Calorie Sugar Substitute May Be Making You Hungrier, Not Slimmer

Zero-calorie sweeteners might confuse the brain, especially in people with obesity

Any Kind of Exercise, At Any Age, Boosts Your Brain

Even light physical activity can sharpen memory and boost mood across all ages.

A Brain Implant Just Turned a Woman’s Thoughts Into Speech in Near Real Time

This tech restores speech in real time for people who can’t talk, using only brain signals.

Using screens in bed increases insomnia risk by 59% — but social media isn’t the worst offender

Forget blue light, the real reason screens disrupt sleep may be simpler than experts thought.

We Should Start Worrying About Space Piracy. Here's Why This Could be A Big Deal

“We are arguing that it’s already started," say experts.