Oldest Fossil Ever Found Dated To 3.5 Billion Years Ago
For humans, 100-years is a long time and it's hard for our minds to comprehend that sort of time. That is a tiny amount of time in the scheme of things for our planet. Humans have been around for what seems to be an eternity dating back 3 million years. Scientists have recently dated what they claim to be the oldest fossils showing that even that 3-million-years is the blink of an eye on a cosmic scale.
This fossil has been dated and has proven that the first lifeforms on Earth were here 3.5 billion years ago. The dating of the fossil puts to rest a decades-long dispute among scientist over what is the oldest fossil found. Using new techniques for aging fossils, scientists have confirmed that 3.5 billion years ago bacteria and microbes were on the planet, possibly before the planet had oxygen.
The research was led by a paleobiologist William Schopf from the University of California-Los Angeles and a geoscientist John Valley of the University of Wisconsin-Madison. The specimens studied are mostly extinct today and are bacteria and microbes found in 1982 at the Apex Chert. This is a rock formation in Western Australia. The specimens studied were inside a piece of rock.
The argument in scientific circles came in that Schopf originally dated the fossils in the rock using radiometric analysis as having been alive 3.45 billion years ago. This led to the inference that life was on Earth a billion years before people thought it existed. The new dating method used a secondary ion mass spectrometer from the University of Wisconsin and separated the carbon in each fossil into isotopes, so the carbon-isotope makeup of each fossil could be examined and compared to other rocks from the era.
The different carbon-isotope ratios between the fossils and rocks of the same era without fossil proved Schopf correct. The results were proof that the fossils of microbes and bacteria in the rock are as old as the rock itself. The fossils were determined to include five species with two being photosynthesizers, two methane-consuming organisms, and one that produced methane.
SOURCE: Quartz