Web address:
http://www.sciencedaily.com/releases/2008/07/
080707134402.htm
Simple Life Form May Have Existed 700 Million Years Earlier Than Previously
Thought
enlarge
Diamonds 4.2 billion years old found trapped inside the Jack Hills zircon
crystals are the oldest-known samples of Earth's carbon. (Credit: Image
courtesy of Curtin University)
ScienceDaily (July 8, 2008) — The accepted timeframe for the beginnings of life
on Earth is now being questioned by a Curtin University of Technology led team
of scientists, after finding a key indicator to the earliest life forms in
diamonds from Jack Hills in Western Australia.
The 4.2-billion-year-old diamonds found trapped inside the Jack Hills zircon
crystals are the oldest-known samples of Earth’s carbon. The Curtin led team’s
discovery of very high concentrations of carbon 12, or “light carbon” within
these crystals is remarkable as it is a feature usually associated with organic
life.
Dr Alexander Nemchin from Curtin’s Department of Applied Geology and the
project leader believes the latest research will revive debate on the early
evolution of life on Earth.
“We believe this find to be the oldest terrestrial light carbon reservoir
discovered so far,” Dr Nemchin said.
Evidence for ancient life stretches back in time to at least 3.5 billion years
ago, in the form of single-celled organisms that did not require oxygen. The
discovery of light carbon in the Jack Hills crystals raises the question – did
a simple life form exist on Earth 700 million years earlier than previously
thought?
“We interpret the range of light carbon values observed in these inclusions as
a unique chemical marker that opens up the possibility of biological activity
during the period not long after the Earth’s formation,” Dr Nemchin said.
The researchers report the composition of 22 diamond and graphite inclusions
from 18 Jack Hills zircon grains in the journal Nature.
“The discovery challenges our fundamental understanding of processes active in
the early history of the Earth. It suggests that life may well have appeared
on Earth long before the period of heavy-meteorite bombardment believed by some
to have initiated the emergence of life on Earth,” Dr Nemchin said.
“Alternatively, it requires some other process to create the light carbon
values, which would then question the widely held assumption that light carbon
means life.”
The discovery will assist mankind in our understanding of the development of
the planet and help us to better assess the conditions of the Earth up to 4,500
billion years ago.
Background
In 1983, a Curtin project team discovered extremely old zircon crystals in a
collection of rocks located between Meekathara and Carnarvon. Twenty years
later, the oldest diamonds were unexpectedly discovered in these rocks by many
of the original team.
The recent paper in Nature is written by a team of people made up of Curtin
University academic and Project Leader, Dr Alexander Nemchin, Martin Whitehouse
from the Swedish Museum of Natural History, Martina Menneken and Dr Thorston
Geisler a Masters student and her supervisor from the University of Munster’s
Institute of Mineralogy, and Professors Pidgeon and Wilde from Curtin
University’s Applied Geology Department, who originally identified the old
zircons.
Journal reference:
1. Nemchin et al. A light carbon reservoir recorded in zircon-hosted diamond
from the Jack Hills. Nature, 2008; 454 (7200): 92 DOI: 10.1038/nature07102
Adapted from materials provided by Curtin University.
Need to cite this story in your essay, paper, or report? Use one of the
following formats:
APA
MLA
Curtin University (2008, July 8). Simple Life Form May Have Existed 700 Million
Years Earlier Than Previously Thought. ScienceDaily. Retrieved July 8, 2008,
from http://www.sciencedaily.com /releases/2008/07/080707134402.htm
Web address:
http://www.sciencedaily.com/releases/2008/07/
080707134402.htm
Simple Life Form May Have Existed 700 Million Years Earlier Than Previously
Thought
enlarge
Diamonds 4.2 billion years old found trapped inside the Jack Hills zircon
crystals are the oldest-known samples of Earth's carbon. (Credit: Image
courtesy of Curtin University)
ScienceDaily (July 8, 2008) — The accepted timeframe for the beginnings of life
on Earth is now being questioned by a Curtin University of Technology led team
of scientists, after finding a key indicator to the earliest life forms in
diamonds from Jack Hills in Western Australia.
The 4.2-billion-year-old diamonds found trapped inside the Jack Hills zircon
crystals are the oldest-known samples of Earth’s carbon. The Curtin led team’s
discovery of very high concentrations of carbon 12, or “light carbon” within
these crystals is remarkable as it is a feature usually associated with organic
life.
Dr Alexander Nemchin from Curtin’s Department of Applied Geology and the
project leader believes the latest research will revive debate on the early
evolution of life on Earth.
“We believe this find to be the oldest terrestrial light carbon reservoir
discovered so far,” Dr Nemchin said.
Evidence for ancient life stretches back in time to at least 3.5 billion years
ago, in the form of single-celled organisms that did not require oxygen. The
discovery of light carbon in the Jack Hills crystals raises the question – did
a simple life form exist on Earth 700 million years earlier than previously
thought?
“We interpret the range of light carbon values observed in these inclusions as
a unique chemical marker that opens up the possibility of biological activity
during the period not long after the Earth’s formation,” Dr Nemchin said.
The researchers report the composition of 22 diamond and graphite inclusions
from 18 Jack Hills zircon grains in the journal Nature.
“The discovery challenges our fundamental understanding of processes active in
the early history of the Earth. It suggests that life may well have appeared
on Earth long before the period of heavy-meteorite bombardment believed by some
to have initiated the emergence of life on Earth,” Dr Nemchin said.
“Alternatively, it requires some other process to create the light carbon
values, which would then question the widely held assumption that light carbon
means life.”
The discovery will assist mankind in our understanding of the development of
the planet and help us to better assess the conditions of the Earth up to 4,500
billion years ago.
Background
In 1983, a Curtin project team discovered extremely old zircon crystals in a
collection of rocks located between Meekathara and Carnarvon. Twenty years
later, the oldest diamonds were unexpectedly discovered in these rocks by many
of the original team.
The recent paper in Nature is written by a team of people made up of Curtin
University academic and Project Leader, Dr Alexander Nemchin, Martin Whitehouse
from the Swedish Museum of Natural History, Martina Menneken and Dr Thorston
Geisler a Masters student and her supervisor from the University of Munster’s
Institute of Mineralogy, and Professors Pidgeon and Wilde from Curtin
University’s Applied Geology Department, who originally identified the old
zircons.
Journal reference:
1. Nemchin et al. A light carbon reservoir recorded in zircon-hosted diamond
from the Jack Hills. Nature, 2008; 454 (7200): 92 DOI: 10.1038/nature07102
Adapted from materials provided by Curtin University.
Need to cite this story in your essay, paper, or report? Use one of the
following formats:
APA
MLA
Curtin University (2008, July 8). Simple Life Form May Have Existed 700 Million
Years Earlier Than Previously Thought. ScienceDaily. Retrieved July 8, 2008,
from http://www.sciencedaily.com /releases/2008/07/080707134402.htm
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