Fossil Discovery Reveals Life Existed On Earth At Least 3.5 Billion Years Ago
- 6 years ago
A fossil discovery shows that life on Earth began at least 3.5 billion years ago.
A new look at the world's oldest known fossils suggests there was life on Earth 3.5 billion years ago.
The microscopic remnants, which were found in Western Australia in 1982 and first examined in the early 1990s, have been studied a number of times, but never this closely.
Scientists with UCLA and the University of Wisconsin-Madison "...polished each microfossil in the sample, one micrometer at a time," and then examined them through, "a secondary ion mass spectrometer."
That allowed them "to separate the carbon composing each fossil into its constituent isotopes and measure their ratios."
"The differences in carbon isotope ratios correlate with their shapes. If they're not biological there is no reason for such a correlation," John Valley, one of the researchers, notes. "Their C-13-to-C-12 ratios are characteristic of biology and metabolic function."
A release from the University of Wisconsin-Madison reports further analysis revealed that the microbes were simple forms that lived by converting sunlight into energy and others that emitted or consumed methane, "a gas believed to be an important constituent of Earth's early atmosphere before oxygen was present."
It also states that, according to one of the scientists, "studies such as this one…indicate life could be common throughout the universe."
A new look at the world's oldest known fossils suggests there was life on Earth 3.5 billion years ago.
The microscopic remnants, which were found in Western Australia in 1982 and first examined in the early 1990s, have been studied a number of times, but never this closely.
Scientists with UCLA and the University of Wisconsin-Madison "...polished each microfossil in the sample, one micrometer at a time," and then examined them through, "a secondary ion mass spectrometer."
That allowed them "to separate the carbon composing each fossil into its constituent isotopes and measure their ratios."
"The differences in carbon isotope ratios correlate with their shapes. If they're not biological there is no reason for such a correlation," John Valley, one of the researchers, notes. "Their C-13-to-C-12 ratios are characteristic of biology and metabolic function."
A release from the University of Wisconsin-Madison reports further analysis revealed that the microbes were simple forms that lived by converting sunlight into energy and others that emitted or consumed methane, "a gas believed to be an important constituent of Earth's early atmosphere before oxygen was present."
It also states that, according to one of the scientists, "studies such as this one…indicate life could be common throughout the universe."