The moment life got a move-on more than two billion years ago
LIFE was creeping and crawling about the Earth 1.5billion years earlier than previously thought, according to scientists whose discovery could rewrite the known course of evolution.
Previously it was thought that crea- tures began moving properly around 500 million years ago, shortly before the Cambrian explosion which sparked the first vertebrates.
Bacteria had previously flicked their tails, known as flagella, to move around but no multicellular organisms had achieved locomotion. However, fossils dating from 2.1billion years ago have shown that cells had already started to group together to form tiny slug-like organisms which slunk through the mud of seabeds in search of food.
The tubular fossils were found in rocks in Gabon, west Africa, by an international team including experts from Cardiff University.
Dr Ernest Chi Fru, from the university’s school of Earth and ocean sciences, said: “It is plausible that the organisms behind this phenomenon moved in search of nutrients and oxygen that were produced by bacteria mats on the sea floor-water interface.
“The results raise a number of fascinating questions about the history of life on Earth, and how and when organisms began to move. Was this a primitive biological innovation, a prelude to more perfected forms of locomotion seen around us today, or was this simply an experiment that was cut short?”
The earliest evidence for life on Earth comes from fossils of microscopic bacteria discovered in rock formations in Quebec, Canada, which may date as far back as 4.2billion years.
But it was not until the Ediacaran period, around 570million years ago, that creatures with complex locomotion appeared, such as Kimberella, a type of mollusc which shuffled along the seabed feeding on microbes.
However, these new fossil findings in the Franceville Basin, a shallow ancient inland sea which existed 2.1billion years ago in modern Gabon, show that basic life forms had learned to move far earlier.
They also show the first evidence of multicellular organisms, 300 million years earlier than previously recorded.
Researchers believe they may have operated in a similar way to tiny groups of amoebae which, when resources become scarce, cluster together to form a type of slug which moves to find a more favourable environment.
The research was published in the journal Proceedings of the National Academy of Sciences.