Theoretical origin of life; new earliest even earlier? (Introduction)

by David Turell , Thursday, January 25, 2018, 14:35 (2273 days ago) @ David Turell

A review of all the findings about the possible earliest forms. It is apparent life didn't take long to start:

https://www.quantamagazine.org/fossil-discoveries-challenge-ideas-about-earths-start-20...

"From a seam in one of these hills, a jumble of ancient, orange-Creamsicle rock spills forth: a deposit called the Apex Chert. Within this rock, viewable only through a microscope, there are tiny tubes. Some look like petroglyphs depicting a tornado; others resemble flattened worms. They are among the most controversial rock samples ever collected on this planet, and they might represent some of the oldest forms of life ever found.

"Last month, researchers lobbed another salvo in the decades-long debate about the nature of these forms. They are indeed fossil life, and they date to 3.465 billion years ago, according to John Valley, a geochemist at the University of Wisconsin. If Valley and his team are right, the fossils imply that life diversified remarkably early in the planet’s tumultuous youth.

"The fossils add to a wave of discoveries that point to a new story of ancient Earth. In the past year, separate teams of researchers have dug up, pulverized and laser-blasted pieces of rock that may contain life dating to 3.7, 3.95 and maybe even 4.28 billion years ago. All of these microfossils — or the chemical evidence associated with them — are hotly debated. But they all cast doubt on the traditional tale.

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"Many geologists now think Earth may have been tepid and watery from the outset. The oldest rocks in the record suggest parts of the planet’s crust had cooled and solidified by 4.4 billion years ago. Oxygen in those ancient rocks suggest the planet had water as far back as 4.3 billion years ago. And instead of an epochal, final bombardment, meteorite strikes might have slowly tapered off as the solar system settled into its current configuration.

“'Things were actually looking a lot more like the modern world, in some respects, early on. There was water, potentially some stable crust. It’s not completely out of the question that there would have been a habitable world and life of some kind,” said Elizabeth Bell, a geochemist at the University of California, Los Angeles.

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"Today, the oldest evidence for possible life — which many scientists doubt or outright reject — is at least 3.77 billion years old and may be a stunningly ancient 4.28 billion years old.

"In March 2017, Dominic Papineau, a geochemist at University College London, and his student Matthew Dodd described tubelike fossils in an outcrop in Quebec that dates to the basement of Earth’s history. The formation, called the Nuvvuagittuq (noo-voo-wog-it-tuck) Greenstone Belt, is a fragment of Earth’s primitive ocean floor. The fossils, about half the width of a human hair and just half a millimeter long, were buried within. They are made from an iron oxide called hematite and may be fossilized cities built by microbial communities up to 4.28 billion years ago, Dodd said.

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"Then in September 2017, researchers in Japan published an examination of graphite flakes from a 3.95-billion-year-old sedimentary rock called the Saglek Block in Labrador, Canada. Yuji Sano and Tsuyoshi Komiya of the University of Tokyo argued their graphite’s carbon-isotope ratio indicates it, too, was made by life. But the graphite flakes were not accompanied by any feature that looked like a fossil; what’s more, the history of the surrounding rock is murky, suggesting the carbon may be younger than it appears.

"Farther to the east, in southwestern Greenland, another team had also found evidence of ancient life. In August 2016, Allen Nutman of the University of Wollongong in Australia and colleagues reported finding stromatolites, fossil remains of microbes, from 3.7 billion years ago.

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"In research published in 2015, Bell and her coauthors presented evidence for graphite embedded within a tiny, 4.1-billion-year-old zircon crystal from the same Jack Hills. The graphite’s blend of carbon isotopes hints at biological origins, although the finding is — once again — hotly debated.

“'Are there other explanations than life? Yeah, there are,” Bell said. “But this is what I would consider the most secure evidence for some sort of fossil or biogenic structure.'”

Comment: A very hospitably designed Earth had life pop up easily. The evidence points to God at work.