Evidence of earliest life on Earth disputed

October 17, 2018
Credit: CC0 Public Domain

When Australian scientists presented evidence in 2016 of life on Earth 3.7 billon years ago—pushing the record back 220 million years—it was a big deal, influencing even the search for life on Mars.

But that discovery, based on an analysis of primordial rocks in Greenland, has now been challenged, with another team of researchers arguing in a study published Wednesday that the structures presented as proof of were, in fact, geologically forged by underground heat and pressure.

The truth hinges on whether the cone-shaped formations in question are genuine stromatolites, layered structures left in the wake of water-dwelling microorganisms.

Previously, the earliest confirmed stromatolites were found in 3.45-billion year old rocks in Australia.

Being able to accurately date the first stirrings of life on our young planet—roughly a billion years old at the time—has important implications for understanding how it emerged and evolved.

Writing in the journal Nature, Abigail Allwood of the California Institute of Technology and colleagues analysed the three-dimensional shape of the disputed formations, along with their orientation in space and chemical composition.

The 3-D view led them to conclude that the alleged fossils lacked internal layers, a signature trait of stromatolites. Upon closer examination, the cone-like shapes were shown to be ridges that typically arise over millions of years through a natural deforming process called metamorphism.

Also missing, they said, were the chemical traces of microbe activity.

"We believe that the current evidence does not support the interpretation of these structures as 3.7 billion-year-old stromatolites," Allwood's team concluded.

Their analysis, the study continued, should also serve as a "cautionary tale" in interpreting rock formations in the search for life on Mars.

Mark Van Zuilen, a geomicrobiologist at the Institut de Physique du Globe in Paris, said the reassessment is convincing, and suggests the Australian stromatolites should regain their status as the earliest confirmed proof of on Earth.

"These observations provide strong evidence for physical rock deformation and therefore offer a non-biological explanation for the observed structures," he commented in Nature.

Allen Nutman, a professor at the University of Wollongong in Australia and lead researcher on the 2016 study, was not available for comment.

Explore further: Oldest fossils point to thriving life on young Earth

More information: Abigail C. Allwood et al. Reassessing evidence of life in 3,700-million-year-old rocks of Greenland, Nature (2018). DOI: 10.1038/s41586-018-0610-4

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18 comments

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FredJose
2.5 / 5 (11) Oct 18, 2018
No matter how soon or late life is supposed to have arisen on earth, the fact of the matter is that
life cannot spontaneously arise from non-living materials all by itself via random chemical and physical processes. This is indisputable.
It is non-science to assume (which people are doing right now) that it is possible and then blatantly broadcasting it as if it were a fact.
zz5555
4.1 / 5 (9) Oct 18, 2018
life cannot spontaneously arise from non-living materials all by itself via random chemical and physical processes.

Of course it can. It doesn't even appear to be particularly difficult - at least statistically (http://www.talkor...rob.html ). Stating it couldn't without any evidence is non-science. And remember, none of the chemical or physical processes are random.
TheGhostofOtto1923
4 / 5 (8) Oct 18, 2018
Of course it can. It doesn't even appear to be particularly difficult
Godders feel justified in making unsubstantiated declarations and pronouncements with absolutely no evidence - their books are comprised of nothing BUT unsubstantiated declarations and pronouncements.

And their gods all celebrate and sanctify this behavior by calling it faith.

So yeah - fred can declare absolutely anything he wants to and because hes a pious believer he feels he's entitled to do so.
24volts
3.4 / 5 (5) Oct 18, 2018
FredJose, I believe in God too but there is absolutely nothing in the Bible or any other religious text I've ever seen that says life hasn't or can't spontaneously evolve from various chemicals. Sorry to have to inform you of that but people need to quit trying to put things in religion that are NOT there.
rrwillsj
2.6 / 5 (5) Oct 18, 2018
What I found interesting about this article was the precautionary tone. Urging researchers seeking life on other worlds to be cautious of making unsustainable claims.

I know the pressure from the funding institions, both government and private, will be intense to be the first to claim success.

Clickbait headlines are cherished by readers as well as editors & publishers.

Even negative data is preferable to incorrect or falsified claims. Negative data does not mean to give up searching for life off Earth. It means "Go look somewhere else!"

Failure is a priceless lesson. Encouraging one to work smarter not harder.

One other important lesson would be. To narrow down and filter out places to look for life. A conservative program encouraging a realistic appraisal of where to efficiently expend limited resources and funding.

Oh man...
The fake conservatives and
fakir-libertarians are going to absolutely hate those suggestions!
Surveillance_Egg_Unit
2.1 / 5 (7) Oct 19, 2018
FredJose, I believe in God too but there is absolutely nothing in the Bible or any other religious text I've ever seen that says life hasn't or can't spontaneously evolve from various chemicals. Sorry to have to inform you of that but people need to quit trying to put things in religion that are NOT there.
says 24volts

The truth being that life hasn't AND can't spontaneously evolve from various chemicals, and no matter how much and how often it is attempted by scientists, it is still not possible UNLESS the ingredients have been derived from something that has previously been, or is presently alive. Such as stem cells. Or sperm and ova.

The Bible was written by scribes long ago who were dictated to by Angels as to what they should write. But the scribes failed to write verbatim, which is why the Bible is confusing (Genesis). Science has come a long way, hasn't it? In biblical times, the concept of evolution didn't even exist. Nomads and sheepherders.

Surveillance_Egg_Unit
2.1 / 5 (7) Oct 19, 2018
life cannot spontaneously arise from non-living materials all by itself via random chemical and physical processes.

Of course it can. It doesn't even appear to be particularly difficult - at least statistically (http://www.talkor...rob.html ). Stating it couldn't without any evidence is non-science. And remember, none of the chemical or physical processes are random.

says zz5555

Of course it cannot be done. IF it were possible, then why hasn't it happened yet? They have been trying for a very long time to make life out of inanimate materials that have never been alive. If it were at all possible, then every planet in the galaxy, under the right conditions, would be full of life forms that had been made from a bunch of chemicals, heat and water.
Why, it could even be done in your kitchen if it was so easy. A little flour, sugar, water sitting on a heat source or under a heating lamp.
LOL Do you have evidence it can be done?
Surveillance_Egg_Unit
2.3 / 5 (6) Oct 19, 2018
So it is the Australian stromatolites that are the actual earliest confirmed proof of life on Earth, not the physical rock deformations in Greenland that offer no evidence of biological explanation. Very interesting.
Surveillance_Egg_Unit
2.1 / 5 (7) Oct 19, 2018
@zz5555
I copied your link to read the rest of it later. The author is, of course, fully biased for abiogenesis, therefore he is unable to show any impartiality as any good researcher would have done. He is in very deep into his religion, to the exclusion of any alternatives. Too late for that one, just as it is too late for SpookyOtto and company.
drrobodog
3 / 5 (6) Oct 19, 2018
The Bible was written by scribes long ago who were dictated to by Angels as to what they should write. But the scribes failed to write verbatim, which is why the Bible is confusing (Genesis).

While I don't believe divine beings, if I ever were too, at the least they would need to be competent.
Bart_A
2.3 / 5 (6) Oct 19, 2018
It takes more faith to believe in the false concept of evolution, than to believe in a God that made the amazing earth that we live in.
Captain Stumpy
4 / 5 (4) Oct 19, 2018
@drrobodog
While I don't believe divine beings, if I ever were too, at the least they would need to be competent.
I know, right?
http://s1027.phot...&o=0

.

.

@bart
It takes more faith to believe in ... evolution

http://s1027.phot...&o=0
zz5555
5 / 5 (1) Oct 19, 2018
It takes more faith to believe in the false concept of evolution, than to believe in a God that made the amazing earth that we live in.

Keep in mind that evolution can be and has been observed, so we know it exists. Can you say the same for observing your god creating a species?

I'm continually surprised at the arrogance of you fake Christians who believe you can tell your gods how to do things. I suppose it's because you all invent god in your own minds, but I'd have thought that at least a few of you would be self-aware enough to see how arrogant it is.
Captain Stumpy
3.8 / 5 (5) Oct 19, 2018
@zz5555
but I'd have thought that at least a few of you would be self-aware enough to see how arrogant it is
the ones who are rational and self-aware in such a manner don't post bullsh*t religion on science sites (see links in my last post)
Phyllis Harmonic
3.4 / 5 (5) Oct 19, 2018
It takes more faith to believe in the false concept of evolution, than to believe in a God that made the amazing earth that we live in.


Facts are independent of belief. We have factual evidence of evolution, so belief is not required. On the other hand, astonishment is not evidence. Lastly, reason imposes a greater intellectual burden than simple acceptance, which is why so many flock to religion- religion doesn't require much in the way of cognitive resources.
torbjorn_b_g_larsson
3 / 5 (4) Oct 19, 2018
A notable detail is that the first author on the criticism paper is Abigail Allwood, who 2006 published the 3.43 Strelley Pool stromatolite candidate [ https://www.natur...ure04764 ]. That paper was notable for its many microscale details that testified to its stromatolite origin.

I haven't read the original stromatolite paper and so far browsed the new, but the latter looks good to due to the find of a non-conformative tilted exemple, the absence of fine layering and the null hypothesis - chemical signature (i.e. found in the surrounding). Since I am no geologist it will be interesting to see the original group respond to it.

As for the ramifications, there are spurious metabolic biosignatures in these rocks and there are even older similar, all in metamorphic sediments or as igneous inclusions.

[tbctd]
torbjorn_b_g_larsson
3 / 5 (4) Oct 19, 2018
[ctd]

A new method from some of the best groups have therefore attempted to integrate both fossil and genetic evidence [ https://www.natur...8-0644-x , "Integrated genomic and fossil evidence illuminates life's early evolution and eukaryote origin", Betts et al, Nature Ecology & Evolution, 2018]. Modern stromatolites are often associated to cyanobacteria, but their diversification happened mostly after the atmosphere oxygenation and the stem lineage dates to around 3.3 Ga which could fit the younger Strelley Pool claim and tend to undermine the Isua claim.

***
On the sad religious claims is not much to say for science interested, since they are obviously both trolling and false. In real life we see that life emerge from non-life since life exist now but the early planet was sterile for sure. But moreover we have also direct observation of evolution from rock over half alive cells to modern life [ https://www.natur...l2016116 ].
rrwillsj
2.3 / 5 (3) Oct 20, 2018
To quote James Dosher "Calling yourself a Christian because you are sitting in a church on Sunday? Is the same as sitting in your garage and calling yourself an automobile!"

Considering their long history of plagiarizing other peoples work. Without contributing anything inventive or even constructive. With a complete lack of intelligent coherence.

All the religious, the denier shills and EU/Aether/Nuclear Orgpne cultists share a sordid proclivity for fakery and fraud.

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