About 700 million years ago, the world was thought to have experienced the most severe ice age. Scientists described this period as Snowball Earth.
This threatened the survival of the planet’s primitive living things such as oxygen-dependent marine life and early animals as well, such as sponges.
Glacial meltwater was a crucial lifeline
New geological evidence uncovered by experts at McGill University in Montreal found that glacial meltwater offered a crucial lifeline back then to the microscopic organisms, which are called eukaryotes.
“The evidence suggests that although much of the oceans during the deep freeze would have been uninhabitable due to a lack of oxygen, in areas where the grounded ice sheet begins to float there was a critical supply of oxygenated meltwater,” stated McGill University sedimentologist Maxwell Lechte in a press statement.
Before this, scientists believed that oxygen-dependent life might have been restricted only to meltwater puddles on the surfaces of the ice.
There’s a new study that has been just published a couple of days ago in the journal Proceedings of the National Academy of Sciences.
It’s been revealed that this study provides evidence of “oxygen oases” below the ice. In such locations, the glacier meets the sea.
Such oxygen oases would have allowed primitive life forms to wait out the ice age, according to the latest reports coming from CNN.
Diversification into more complex forms of life
Lechte also said that all this did not only help life survive on Earth during this icy period, but the huge glaciation that engulfed our beloved planet could have actually played a massive role in the evolution of more complex lifeforms.
More than that, “The fact that the global freeze occurred before the evolution of complex animals suggests a link between Snowball Earth and animal evolution,” Lechte stated.
He concluded by saying that “These harsh conditions could have stimulated their diversification into more complex forms.”