homehome Home chatchat Notifications


World's oldest plant-like fossils indicate we might have to rethink emergence of multicellular life

We might have to recalibrate the tree of life.

Mihai Andrei
March 16, 2017 @ 1:31 pm

share Share

Scientists have uncovered 1.6 billion-year-old fossils from multicellular organisms, likely red algae. The findings indicate that multicellular life evolved much faster than we thought.

X-ray tomographic picture (false colors) of fossil thread-like red algae. Credit: Stefan Bengtson; CCAL

The scientists found the incredibly well-preserved fossils in sedimentary rocks called phosphorites at Chitrakoot in central India, embedded in fossil mats of cyanobacteria, called stromatolites. Although it’s hard to say for sure what they are, they’re definitely multicellular and they seem to resemble the structure of modern red algae.

“Back in the days when they were living and growing this would have been a shallow marine system with plenty of sunlight,” says study co-author and geobiologist Therese Sallstedt.

Red algae are one of the oldest groups of eukaryotic algae, consisting of mostly multicellular, marine algae, including many notable seaweeds. Researchers found two types of presumed algae: one type is thread-like, while the other consists of fleshy colonies. The team looked at them with help of synchrotron-based X-ray tomographic microscopy finding, among others, regularly recurring platelets which they believe are chloroplasts — the specialized organelles in which photosynthesis takes place.

“You cannot be a hundred per cent sure about material this ancient, as there is no DNA remaining, but the characters agree quite well with the morphology and structure of red algae,” says Stefan Bengtson, Professor emeritus of palaeozoology at the Swedish Museum of Natural History.

The earliest life form ever discovered dates from 3.5 billion years ago (though a more recent estimate suggests 3.7 billion years ago). These were simple, single-celled organisms, lacking a nucleus and other organelles. For the longest time, all life on Earth remained microscopic, up until 600 million years ago, when the first “visible life” emerged — multicellular organisms emerged a bit earlier, 1.2 billion years old. Or so we thought.

“The ‘time of visible life’ seems to have begun much earlier than we thought,” says Stefan Bengtson.

If these findings stand, it might force us to recalibrate the early days of the tree of life, because these predate the oldest algae by 400 million years. The problem with that timeframe is that fossils are extremely scarce,

“[Cyanobacteria] changed forever the state of the atmosphere, releasing oxygen that we breathe,” Sallstedt says. “As did plants, in a way. They didn’t invent photosynthesis, but they took it to the next level.”

Journal Reference: Stefan Bengtson, Therese Sallstedt, Veneta Belivanova, Martin Whitehouse. Three-dimensional preservation of cellular and subcellular structures suggests 1.6 billion-year-old crown-group red algae. PLOS Biology, 2017; 15 (3): e2000735 DOI: 10.1371/journal.pbio.2000735

share Share

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.

An Experimental Drug Just Slashed Genetic Heart Risk by 94%

One in 10 people carry this genetic heart risk. There's never been a treatment — until now.

We’re Getting Very Close to a Birth Control Pill for Men

Scientists may have just cracked the code for male birth control.

A New Antibiotic Was Hiding in Backyard Dirt and It Might Save Millions

A new antibiotic works when others fail.

Researchers Wake Up Algae That Went Dormant Before the First Pyramids

Scientists have revived 7,000-year-old algae from Baltic Sea sediments, pushing the limits of resurrection ecology.

A Fossil So Strange Scientists Think It’s From a Completely New Form of Life

This towering mystery fossil baffled scientists for 180 Years and it just got weirder.

ChatGPT Seems To Be Shifting to the Right. What Does That Even Mean?

ChatGPT doesn't have any political agenda but some unknown factor is causing a subtle shift in its responses.

This Freshwater Fish Can Live Over 120 Years and Shows No Signs of Aging. But It Has a Problem

An ancient freshwater species may be quietly facing a silent collapse.