The coordinator of the research team who made the discovery, in ancient rocky sediments in Australia, how the first animals appeared on planet Earth, according to a study published this week in the journal Nature, speaks of “revolution in ecosystems”.
To get to these traces, scientists at the National University of Australia, a small public university located in Canberra, extracted molecules of organisms from fossil sediments.
“These molecules tell us that [life]really became interesting 650 million years ago. It was a revolution in ecosystems, it was the increase [in concentration]of algae”, said Team Coordinator Jochen Brocks, Quoted in a statement from the university.
For this researcher, the great amount of nutrients present in the oceans, as well as the cooling of the surface temperature of the Earth, were factors that created the ideal conditions for the rapid spread of algae, which later led to the transition of the oceans dominated by Ecosystems already inhabited by other more complex forms of life.
Jochen Brocks explained that algae, as the base elements of the food chain, “provided the energy needed for the evolution of complex ecosystems where ever-larger animals, including humans, could thrive on Earth”.
However, well before all this happens, the planet has been covered with ice for more than 50 million years, according to the theory of ‘Earth, snowball’. A theory whose hypothesis suggests that the Earth was completely covered with ice during the Cryogenian period, between 790 and 630 million years ago. This hypothesis was originally proposed to explain the presence of traces of glaciers at tropical latitudes.
“When glaciers melted, during a period of extreme global warming, the rivers brought torrents of nutrients to the oceans”, Brocks concluded.