Ancient mucus trail led to oldest evidence of mobility on Earth

Posted Monday, 11 February 2019 ‐ CNN

(CNN)A fossilized mucus trail led to the discovery of the oldest evidence for mobility on Earth, dating to 2.1 billion years ago, according to a study published Monday in the journal Proceedings of the National Academy of Sciences. Previously, the oldest known traces of movement were dated to 570 million years ago, so this discovery significantly pushes back the timeline for mobile life.Researchers have struck science gold twice now in Gabon's Fraceville Basin, where fossils are extremely well-preserved. The international research team found the earliest evidence for multicellular organisms there, and now, they have found fossilized tracks signifying mobility. This means some multicellular organisms were able to navigate their primitive marine ecosystem, rich in organic matter, by moving through the mud. In order to study the tracks, the researchers used a nondestructive imaging technique involving X-rays to analyze and reconstruct the traces in 3D. Remarkably, the millimeters-wide tubular structures are vertical as well as horizontal. Horizontal was expected; that would be natural movement as they pushed through the sediment layer. Vertical signifies more complexity and requires different movement. Although vertical movement was possible only in soft muds, like a mixture of clay and organic matter, the researchers were still surprised to see those varying tracks. Over time, these sediments turned into black shale. Although the tracks are incredibly well-preserved, it's difficult to say what the organisms that made them looked like. The researchers believe they acted like colonial amoebae or slime molds. These cluster together to form a slug when resources disappear, a formation that allows them to move to an environment that will supply what they need.This isn't the oldest evidence for life on Earth, which is bacterial. "Life on our planet could be nearly around 3.8 billion years old," said Abder El Albani, study author and professor at the Universite de Poitiers in France, in an email. "But for nearly 2 billion years it was bacterial. Even if their precise place on the tree of life is still a matter of discussion and deserves additional research, the Gabonionta are the earliest multicellular macroscopic organisms discovered so far. But these more complex organism emerged during an interesting time.The researchers studied the sediments in which they found the tracks of "Gabonionta," as they're calling the organisms. They were found under what would have been a shallow water column full of oxygen. Previously, Earth was a more harsh place, with a carbon dioxide atmosphere and significant lack of oxygen. But oxygen was prevalent during the time of Gabonionta, which probably used aerobic respiration to live, turning things like fats and sugars into energy. Mobility allowed these organisms to be more complex."What matters here is their astonishing complexity and diversity in shape and size, and likely in terms of metabolic, developmental and behavioural patterns, including the just discovered earliest evidence of motility," El Albani said.But that in itself leads to another mystery. About 2.083 billion years ago, there was a significant drop in oxygen on Earth, leading to a long period of harsh conditions that would have cut short or limited this kind of evolution of complex organisms, El Albani said.So did this complex organism and its movement lead to the evolution of better and more sophisticated movement, or was it cut short by the lack of atmospheric oxygen? Only time, and more research, will tell. For now, Gabonionta has no analog in later times, the researchers said.

Other articles published by CNN

Posted Friday, 17 January 2020 ‐ CNN

(CNN)House Democrats on Friday released new documents from indicted Rudy Giuliani associate Lev Parnas ahead of the Senate trial that includes new information about the apparent surveillance of former US Ambassador Marie Yovanovitch.The documents appear...

Posted Friday, 17 January 2020 ‐ CNN

(CNN)Three Georgia men allegedly involved in a white supremacist group known as The Base have been arrested, the Floyd County Police Department announced Friday, one day after three other alleged group members were arrested in other parts of the...

Posted Friday, 17 January 2020 ‐ CNN

Holly Thomas is a writer and editor based in London. She tweets @HolstaT. The opinions expressed in this commentary are solely those of the author. View more opinion articles on CNN. (CNN)You'd think that, after nearly a quarter of a century, Eminem...

Posted Friday, 17 January 2020 ‐ CNN

Washington (CNN)No one knows who is going to win the Iowa caucuses in 17 days' time. But here's something to think about: What if more than one candidate wins?WHAT???? you ask. How can that be? (Cue "The Outsider" trailer.)The answer: Unlike in past...

Posted Friday, 17 January 2020 ‐ CNN

(CNN)A Georgia sheriff's deputy has been arrested on a charge of rape after a female suspect alleged that he had inappropriate contact with her, according to the Richmond County Sheriff's Office. The deputy, Kendrick Quick, 38, was arrested Thursday on...

Posted Friday, 17 January 2020 ‐ CNN

Washington (CNN)The US Department of Agriculture on Friday announced two new proposals that would give school nutrition professionals "more flexibility" in what they serve to students. The Washington Post reports the proposals would allow schools to...

Posted Friday, 17 January 2020 ‐ CNN

(CNN)Attorney General William Barr briefly attended a meeting at the Justice Department last fall between top criminal prosecutors and President Donald Trump's personal attorney Rudy Giuliani, a department official said Friday.The meeting reveals a...

Posted Friday, 17 January 2020 ‐ CNN

(CNN)Two actors fell off a bridge and died while working on the TV series "Sin Miedo a la Verdad," Mexican network Televisa announced on Friday.Jorge Navarro Sánchez and Luis Gerardo Rivera were rehearsing a scene Thursday when the incident took place,...

Posted Friday, 17 January 2020 ‐ CNN

(CNN)Former New York Rep. Chris Collins was sentenced to 26 months in prison on Friday after pleading guilty to federal charges in an insider trading case.The sentence from Judge Vernon Broderick in a New York federal court comes after Collins pleaded...

Posted Friday, 17 January 2020 ‐ CNN

(CNN)CNN has received another 176 pages of notes from major witness interviews during former special counsel Robert Mueller's investigation.This is the fourth time CNN has gotten documents like these from the Justice Department regarding the Mueller...

Posted Friday, 17 January 2020 ‐ CNN

(CNN)Being trapped on a cruise ship sounds bad enough, but imagine that the vessel in question is in outer space. That's the futuristic gag at the center of "Avenue 5," a goofy HBO comedy from "Veep" creator Armando Iannucci, which has its moments but...

Posted Friday, 17 January 2020 ‐ CNN

New York (CNN)Queen Bey's latest wardrobe arrived a day early and it's already breaking the internet.A limited supply of clothes and shoes from Beyoncé Knowles-Carter's new Ivy Park x Adidas retail line dropped at noon on Friday - hours ahead of its...

Posted Friday, 17 January 2020 ‐ CNN

(CNN)Rapper Pop Smoke had just returned from Europe Friday when he was arrested at John F. Kennedy International Airport in New York on a charge of interstate transport of a stolen vehicle. A federal indictment says between November and December last...

Posted Friday, 17 January 2020 ‐ CNN

New York (CNN Business)The Capitol Hill press corps on Friday rallied behind Manu Raju, CNN's senior congressional correspondent, after Republican Sen. Martha McSally of Arizona insulted him on Thursday.The Radio and Television Correspondents...

Posted Friday, 17 January 2020 ‐ CNN

(CNN)Hulu's adaptation of "Little Fires Everywhere" is already sparking interest. That, of course, is inevitable with a cast that includes Reese Witherspoon and Kerry Washington. But the first trailer, which was released on Friday, has bolstered...