11/30/2022 0 Comments Fman appears on earth![]() ![]() deposition occurred from a shallow-water environment.microfossils were deposited at the time the formations originated.The scientists argue for the biogenicity of the fossils along a number of lines that include the fact that: 2 These microfossils include thread-like filaments believed to be remnants of chains of bacterial cells and the remains of biofilms secreted by bacteria. Investigators from Japan and Australia recently reported on the recovery of a new collection of microfossils from three separate localities of the Strelley Pool Formation in Western Australia. The fact that previous work has uncovered separate evidence for sulfate-reducing microbes on early Earth adds further support for dolomite as a biogenic marker. However, when these microbes are around, they remove the dolomite-precipitating inhibitor.Ĭollectively, these lines of evidence argue that the dolomite in the rocks of western Greenland resulted from the metabolic activity of sulfate-reducing microbes. These microbes consume sulfate, which inhibits dolomite precipitation. These scientists suggest field studies and lab experiments have determined that dolomite can precipitate from seawater at low temperatures only if sulfate-reducing bacteria are present. 1 The researchers present evidence that the dolomite was deposited from low-temperature seawater at the time the formations originated. Recently, a team from Australia argued that the dolomite in these formations also reflects biological activity, specifically that of sulfate-reducing bacteria. Other chemical signatures from these formations that have been interpreted as biological remnants include uranium/thorium fractionation and banded iron formations. These deposits display an enrichment of the carbon-12 isotope. The primary evidence for 3.8 billion-year-old life consists of carbonaceous deposits, such as graphite, found in rock formations in western Greenland. They also hope that additional finds will help resolve the controversy.ĭiscovery 1: Dolomite as a New Geochemical Marker for Life Researchers hope that better characterization of existing geochemical and fossil markers will help determine what produced these residues and fossil-like structures. Instead the scientists argue that these signatures were actually created by nonbiological mechanisms that mimicked the chemical residues and structures generated by microorganisms. They agree that the evidence is consistent with what one would expect if life were present on early Earth, but the possibility that the geochemical residues and fossil remains were produced by some abiotic process can’t be ruled out. While many scientists find the evidence for early life on Earth compelling, there are a number who think that the geochemical markers and fossil structures are not bioauthentic. As corroboration, several other types of geochemical and a variety of fossil evidence for life have been recovered in slightly younger rock formations in South Africa and Western Australia, dating at around 3.5 billion years in age. Well, it’s time for another update! Good thing, too, because scientists have recently reported on two studies that shed insight onto the inaugural appearance of life on Earth.Īs discussed in Origins of Life, there are several geochemical signatures in the oldest rock formations that seem to indicate life (microbial bacteria and archaea) was present on Earth by at least 3.8 billion years ago. ![]() (See: “Creation Model Passes Big Test,” “New Discovery Confirms Life’s Early Appearance on Earth,” “Experiencing How Early Life Lived,” and “Now Hear This! New Evidence for Ancient Life!) Since the publication of Origins of Life, I have written several articles updating our origins model with the latest discoveries about first life on Earth. (For a detailed discussion of Earth’s first life see the book Hugh Ross and I coauthored, Origins of Life.) This past year scientists have made some key advances in understanding an important event in history: the timing of life’s first appearance. ![]() The holiday season is the time of the year when many people send out a newsletter providing friends and family members with updates of important events that have taken place over the course of the year. ![]()
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