Evolution: more evidence of early life (Introduction)

by David Turell , Monday, January 22, 2024, 18:10 (304 days ago) @ David Turell

In Africa:

https://www.newscientist.com/article/2413292-traces-of-ancient-life-reveal-a-3-4-billio...

"Manuel Reinhardt at the University of Göttingen in Germany and his colleagues studied rocks from the Buck Reef Chert, part of the Barberton Greenstone Belt in South Africa. The rocks are 3.42 billion years old and are thought to be the preserved remnants of the shallow seas around a chain of volcanic islands.

"The layers of rock contain microscopic blobs of carbon-based matter, believed to be the remains of microorganisms that lived in these seas. Reinhardt and his group subjected this matter to a battery of analyses to determine its chemical makeup, which they used to infer what sort of metabolism these microorganisms had.

"The team focused on the carbon itself. Carbon comes in several forms called isotopes, which are identical apart from the number of neutrons in the nucleus of the atom. The main two carbon isotopes are carbon-12 and carbon-13. Living things prefer to use carbon-12, so biological matter tends to have more carbon-12 and less carbon-13 than non-biological matter.

"However, not all living things are equally good at preferentially absorbing carbon-12. That means the ratio between the two forms can provide clues about an organism’s metabolism.

"Much of the material has a carbon signature that matches photosynthesis: the ability to use light energy to make sugar. This suggests there were enormous quantities of photosynthetic microbes living near the surface of the sea billions of years ago.

"However, some of the blobs had less carbon-12. Photosynthetic organisms can’t achieve this, so Reinhardt says those microbes must have been feeding on a chemical called acetyl coenzyme A.

"Other blobs had still lower levels of carbon-12, suggesting the microbes in them were making either methane or acetate as waste products, which other microbes were then feeding on.

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"The study also adds to the evidence for an early origin of life on Earth, earlier than a crude reading of the fossil record might suggest.

The oldest widely accepted evidence for life is 3.5 billion years old, from Pilbara in Australia. Researchers have reported evidence of older fossils from 3.7 billion years ago or even earlier, but others say the evidence isn’t convincing in most of those cases.

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"What does seem clear is that life is significantly older than 3.5 billion years. “Personally, I think life emerged on Earth during the Hadean [eon], probably about 4.2, 4.1 billion years [ago],” says Westall."

Comment: with the arrival of Earth 4.5 billon years ago such a quick appearance ofc life is surprising. Fits the theory of a designer, not a chance development..