Melbourne woman Dianne McGrath is preparing for life on Mars after making it into the final 100 contenders for the Mars One program.
ANCIENT fossil evidence discovered in Western Australia could dramatically change our understanding of how life began on Earth, vindicate a discarded 19th century theory by Charles Darwin and boost chances we find alien life of Mars.
The fossil discovery was made by scientists at the University of New South Wales, who found what they believe to be evidence of early life in 3.48 billion-year-old hot spring deposits in the Pilbara.
It pushes back our earliest known trace of life on terrestrial land by more than half a billion years.
The discovery could mean that the first spark of life actually emerged in a hot spring on land rather than a hydrothermal vent in the deep sea.
Currently the idea that the first microbial life originated in vents on the sea floor which cooked up the necessary conditions for life is the dominant theory.
However there are counter ideas including the one put forth by Charles Darwin in a 1871 letter to a friend in which he speculated that microbial life originated in a “warm little pond” on Earth.
The reason the marine model has gained such attention is because early evidence of the development of life on land is scarce.
Previously, the world’s oldest evidence for microbial life on land came from 2.7 to 2.9 billion-year-old deposits in South Africa containing organic matter-rich ancient soils.
“Our exciting findings don’t just extend back the record of life living in hot springs by three billion years, they indicate that life was inhabiting the land much earlier than previously thought, by up to about 580 million years,” lead researcher Tara Djokic, from the University of NSW, said.
“This may have implications for an origin of life in freshwater hot springs on land, rather than the more widely discussed idea that life developed in the ocean and adapted to land later.”
The study by Ms Djokic and UNSW Professors Martin Van Kranendonk, Malcolm Walter and Colin Ward, as well as Professor Kathleen Campbell of the University of Auckland, was published in the journal Nature Communications.
The finding is also said to have genuine implications for the search for alien life on Mars and could increase the chances microbial life has developed on the rocky planet.
The Red Planet has ancient hot spring deposits similar in age to those that yielded evidence of the ancient microbes in the Pilbara.
“If life can be preserved in hot springs so far back in Earth’s history, then there is a good chance it could be preserved in Martian hot springs too,” Ms Djokic said.
Within the Pilbara deposits, the scientists identified stromatolites, which are layered rock structures created by communities of ancient bugs.
Other signs of early life included preserved bubbles thought to have been trapped in a sticky microbial substance.
The presence of geyserite, a mineral only found in terrestrial hot spring environments, was evidence that the deposits were formed on land and not in the ocean.
— With AAP