. 24/7 Space News .
EARLY EARTH
A long day for microbes, and the rise of oxygen on Earth
by Staff Writers
Bremen, Germany (SPX) Aug 03, 2021

illustration only

Virtually all oxygen on Earth was and is produced by photosynthesis, which was invented by tiny organisms, the cyanobacteria, when our planet was still a rather uninhabitable place. Cyanobacteria evolved more than 2.4 billion years ago, but Earth only slowly transformed to the oxygen-rich planet we know today.

"We do not fully understand why it took so long and what factors controlled Earth's oxygenation," said geomicrobiologist Judith Klatt. "But when studying mats of cyanobacteria in the Middle Island Sinkhole in Lake Huron in Michigan, which live under conditions resembling early Earth, I had an idea."

Cyanobacteria are late risers
Klatt worked together with a team of researchers around Greg Dick from the University of Michigan. The water in the Middle Island Sinkhole, where groundwater seeps out of the lake bottom, is very low in oxygen. "Life on the lake bottom is mainly microbial, and serves as a working analog for the conditions that prevailed on our planet for billions of years", says Bopi Biddanda, a collaborating microbial ecologist from the Grand Valley State University. The microbes there are mainly purple oxygen-producing cyanobacteria that compete with white sulfur-oxidizing bacteria. The former generate energy with sunlight, the latter with the help of sulfur.

In order to survive, these bacteria perform a tiny dance each day: From dusk till dawn, the sulfur-eating bacteria lie on top of the cyanobacteria, blocking their access to sunlight. When the sun comes out in the morning, the sulfur-eaters move downwards and the cyanobacteria rise to the surface of the mat. "Now they can start to photosynthesize and produce oxygen," explained Klatt.

"However, it takes a few hours before they really get going, there is a long lag in the morning. The cyanobacteria are rather late risers than morning persons, it seems." As a result, their time for photosynthesis is limited to only a few hours each day. When Brian Arbic, a physical oceanographer at the University of Michigan, heard about this diel microbial dance, he raised an intriguing question: "Could this mean that changing daylength would have impacted photosynthesis over Earth's history?"

Daylength on Earth has not always been 24 hours. "When the Earth-Moon system formed, days were much shorter, possibly even as short as six hours," Arbic explained. Then the rotation of our planet slowed due to the tug of the moon's gravity and tidal friction, and days grew longer. Some researchers also suggest that Earth's rotational deceleration was interrupted for about one billion years, coinciding with a long period of low global oxygen levels. After that interruption, when Earth's rotation started to slow down again about 600 million years ago, another major transition in global oxygen concentrations occurred.

After noting the stunning similarity between the pattern of Earth's oxygenation and rotation rate over geological timescales, Klatt was fascinated by the thought that there might be a link between the two - a link that went beyond the "late riser" photosynthesis lag observed in the Middle Island sinkhole. "I realized that daylength and oxygen release from microbial mats are related by a very basic and fundamental concept: During short days, there is less time for gradients to develop and thus less oxygen can escape the mats," Klatt hypothesized.

From bacterial mats to global oxygen
Klatt teamed up with Arjun Chennu, who then also worked at the Max Planck Institute for Marine Microbiology and now leads his own group at the Leibniz Centre for Tropical Marine Research (ZMT) in Bremen. Based on an open-source software developed by Chennu for this study, they investigated how sunlight dynamics link to oxygen release from the mats. "Intuition suggests that two 12-hour days should be similar to one 24-hour day. The sunlight rises and falls twice as fast, and the oxygen production follows in lockstep. But the release of oxygen from bacterial mats does not, because it is limited by the speed of molecular diffusion. This subtle uncoupling of oxygen release from sunlight is at the heart of the mechanism," said Chennu.

To understand how the processes occurring within a day can impact long-term oxygenation, Klatt and her colleagues incorporated their results into global models of oxygen levels. The analysis suggests that the increased oxygen release due to daylength change could have boosted oxygen levels globally. It is a link between the activity of tiny organisms and global processes.

"We tie together laws of physics operating at vastly different scales, from molecular diffusion to planetary mechanics. We show that there is a fundamental link between daylength and how much oxygen can be released by ground-dwelling microbes," said Chennu. "It's pretty exciting. This way we link the dance of the molecules in the microbial mat to the dance of our planet and it's Moon."

Overall, the two major oxygenation events (jumps in oxygen concentration) in Earth's history - the Great Oxidation Event more than two billion years ago and the later Neoproterozoic Oxygenation Event - might be linked to increasing daylength. Hence, increasing daylength could have boosted benthic net productivity sufficiently to impact atmospheric oxygen levels. "Juggling with this wide range of temporal and spatial scales was mind-boggling - and lots of fun," Klatt concludes.

Research Report: "Possible link between Earth's rotation rate and oxygenation"


Related Links
Max-Planck-Gesellschaft
Explore The Early Earth at TerraDaily.com


Thanks for being there;
We need your help. The SpaceDaily news network continues to grow but revenues have never been harder to maintain.

With the rise of Ad Blockers, and Facebook - our traditional revenue sources via quality network advertising continues to decline. And unlike so many other news sites, we don't have a paywall - with those annoying usernames and passwords.

Our news coverage takes time and effort to publish 365 days a year.

If you find our news sites informative and useful then please consider becoming a regular supporter or for now make a one off contribution.
SpaceDaily Monthly Supporter
$5+ Billed Monthly


paypal only
SpaceDaily Contributor
$5 Billed Once


credit card or paypal


EARLY EARTH
Bird brains left other dinosaurs behind
Austin TX (SPX) Aug 03, 2021
Today, being "birdbrained" means forgetting where you left your keys or wallet. But 66 million years ago, it may have meant the difference between life and death - and may help explain why birds are the only dinosaurs left on Earth. Research on a newly discovered bird fossil led by The University of Texas at Austin found that a unique brain shape may be why the ancestors of living birds survived the mass extinction that claimed all other known dinosaurs. "Living birds have brains more comple ... read more

Comment using your Disqus, Facebook, Google or Twitter login.



Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle

EARLY EARTH
Space station mishap caused orbiting lab to rotate 1 1/2 times, NASA says

What you need to know about Starliner's Test-2

Nauka Module incident caused by software failure

Progress 77 and Pirs undocked from Station

EARLY EARTH
Boeing postpones Starliner capsule launch attempt over valve issue

Finding the cause of a fatal problem in rocket engine combustors

German startups launch mini-rocket challenge to SpaceX and co.

Rocket tanks of carbon fibre reinforced plastic proven possible

EARLY EARTH
Earthly rocks point way to water hidden on Mars

Helicopter scouts ridge area for Perseverance

Clays, not water, are likely source of Martian lakes

Zhurong marks 1st anniversary since launch with dune exploration

EARLY EARTH
China's space propaganda blitz endures at slick new planetarium

Shanxi company helps astronauts keep fit in space

How Chinese astronauts stay healthy in space

China's five-star red flag flies proudly on red planet

EARLY EARTH
Next batch of OneWeb satellites set to launch August 20

Iridium granted trio of regulatory approvals in Japan

Inmarsat unveils the communications network of the future

Space company in search for professionals

EARLY EARTH
Experiment bound for Space Station turns down the heat

World's first commercial re-programmable satellite blasts into space

Upgrades to NASA's Space Communications Infrastructure Pave the Way to Higher Data Rates

Metallic glass gears up for 'Cobots,' Coatings, and More

EARLY EARTH
Astronomers show how planets form in binary systems without getting crushed

Galileo Project to search for ET artifacts in galactic space

From the sun to the stars: A journey of exoplanet discovery begins

ALMA images moon-forming disk around alien world

EARLY EARTH
Juno joins Japan's Hisaki satellite and Keck Observatory to solve "energy crisis" on Jupiter

Hubble finds first evidence of water vapor on Ganymede

NASA Awards Launch Services Contract for the Europa Clipper Mission

Juno tunes into Jovian radio triggered by Jupiter's volcanic moon Io









The content herein, unless otherwise known to be public domain, are Copyright 1995-2024 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. All articles labeled "by Staff Writers" include reports supplied to Space Media Network by industry news wires, PR agencies, corporate press officers and the like. Such articles are individually curated and edited by Space Media Network staff on the basis of the report's information value to our industry and professional readership. Advertising does not imply endorsement, agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. General Data Protection Regulation (GDPR) Statement Our advertisers use various cookies and the like to deliver the best ad banner available at one time. All network advertising suppliers have GDPR policies (Legitimate Interest) that conform with EU regulations for data collection. By using our websites you consent to cookie based advertising. If you do not agree with this then you must stop using the websites from May 25, 2018. Privacy Statement. Additional information can be found here at About Us.