3.77-Billion-Year-Old Fossils Found, Could be Earliest Evidence of Life On Earth (theguardian.com)

An anonymous reader shares The Guadian report: Scientists say they have found the world's oldest fossils, thought to have formed between 3.77bn and 4.28bn years ago. Comprised of tiny tubes and filaments made of an iron oxide known as haematite, the microfossils are believed to be the remains of bacteria that once thrived underwater around hydrothermal vents, relying on chemical reactions involving iron for their energy. If correct, these fossils offer the oldest direct evidence for life on the planet. And that, the study's authors say, offers insights into the origins of life on Earth. "If these rocks do indeed turn out to be 4.28 [bn years old] then we are talking about the origins of life developing very soon after the oceans formed 4.4bn years ago," said Matthew Dodd, the first author of the research from University College, London. With iron-oxidising bacteria present even today, the findings, if correct, also highlight the success of such organisms. "They have been around for 3.8bn years at least," said the lead author Dominic Papineau, also from UCL.

Comments

Huh?

[Frosty Piss]

There must be something wrong with their testing protocol, we all know that the earth is about 6,000 years old.

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[beelsebob]

With life being at least 83% as old as the planet according to this result, it makes me begin to wonder "has life been on earth ever since it formed?"

That's clearly not a question we're going to answer today, but it might have drastic impacts on the drake equation if there was some requirement for life that has to happen as the planet forms.

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[MightyMartian]

I'm not a huge fan of panspermia in general, as it seems to add an additional step to a problem, but really just pushes the question back. I can concede that it is possible that Mars, which may have been more conducive to life earlier, may have been the source of life on Earth, but until we find some evidence that life actually existed on Mars at some point, and further can show enough molecular commonality with life on Earth, I think Occam's razor suggests we have to stick for the moment with life being indigenous to Earth. That being said, even if we found life on Mars that appeared to be part of the same twin-nested hierarchy as life on Earth (in other words, we're all on the same family tree), that still wouldn't really answer the question, since it's easily conceivable that the transit could have been the other way; Earth to Mars.

What we do know right now is that some of the most ancient genes suggest these early organisms at the root of the tree of life were autotrophic and probably hung around deep sea vents in waters rich in iron and sulfates (this is the idea behind the iron-sulfur world hypothesis). While this doesn't necessarily discount Mars either, as Mars in this early era had oceans and was very likely geologically active, it still suggests to my mind that Earth is still a pretty clear contender for the source of the life we see today.

A lot will depend on whether we can find other life in the solar system. If we go to Mars or Europa and end up finding organisms that have a clear molecular relationship to life on Earth, it certainly proves the limited form of panspermia happened, whereas if it turns out there is no evident genetic relationship, then that ought to tell us life is pretty damned common in the universe, and even in conditions like the Hadean Epoch, when Earth was quite literally at points a hell, life can not only evolve but possibly even flourish.

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[MightyMartian]

That describes parts of the Hadean Epoch, and in particular the early parts, but there is some evidence that even during the Hadean Epoch there was liquid water, possibly even oceans. From https://en.wikipedia.org/wiki/..., it states that even though surface temperatures were much higher, the much higher atmospheric pressure meant that liquid water could exist. Considering some evidence that the earliest organisms were autotrophic and lived in an environment very much like existing deep sea vents, one can surmise that while this environment would be pretty damned hostile, it would still have had the critical ingredients; water, complex organic chemistry and an abundance of energy.

Re:DBAG

[Anonymous Coward]

Because then you get an entire population of ignorant clueless superstitious barbarians that elect abominations like Trump for their leaders.

If we didn't live in democraties, I would have no problem letting anyone be as clueless and moronic as they want.

Re:The scientist fantasy

[spiritplumber]

If scientists end up in Hell they will terraform it, given an eternity of time.

Lake of fire? OK.

Lake means it has shores, somewhere to colonize. Fire means a recognizable chemistry, which implies a recognizable physics, AND a fairly rapid and high-volume energy transfer from the lake to the atmosphere.

By the time scientists and engineers are done with the place (and I remind you that they have forever to do it, so it WILL get done) you won't be able to afford rent there.

https://www.reddit.com/r/HFY/c...

Re:Earliest evidence of life on Earth?

[The Raven]

I know it's a joke, but just for the sake of discussion I'd like to address it.

Finding out that life took 'only' 100 million years to appear after the formation of liquid oceans makes it a lot more likely that life (as we know it) is ubiquitous in favorable conditions. It means that if we are ever able to investigate the cosmos, we may find that most worlds that have liquid water have at least primitive life on them (rather than 'some' or 'occasional'). And there is always the possibility of life as we don't know it; life in gas giants, on neutron stars, in the gluon soup of the first moments of the cosmos (Stephen Baxter, but I can't remember which story), in the accretion disks of black holes, in the photosphere of stars.

There are so many ways that organization could form out of chaos, and that life would be invisible to us. If there was a form of life that lived in our sun's photosphere how would we tell it existed? We only recently learned that there are microbes in our upper atmosphere that is evolved to survive there permanently... and we flew through it for decades!

The more alien life is, the easier it is for us to overlook or not recognize the signs of its existence. Not only that, but the less likely we are to visit (or closely investigate) the environment it lives in because that environment is inhospitable to us.

So yeah... finding out that life evolved early on on Earth is fascinating, and it really lends weight to the possibility of life being all over the place... even where we have not tried to look.

Re:Earliest evidence of life on Earth?

[MightyMartian]

I remember reading an observation by a chemist or molecular biologist years ago that abiogenesis events might go on all the time, but the problem for any new protolife is that if it appears in an already active biosphere where a fair portion of the existing organisms are very very good at gobbling stray bits of organic material, it's not going to last long at all.