Snowball Earth unlocked: McGill researcher learns how earliest animals survived severe ice age

Snowball Earth unlocked: McGill researcher learns how earliest animals survived severe ice age
Top Stories
Maxwell Lechte examines rock formations in the Flinders Ranges (South Australia). Photo credit: Brennan OConnell / source: McGill University


MONTREAL -- A McGill University researcher is unlocking the secrets of how life survived during Earth s most severe ice age.

The study, led by Department of Earth and Planetary Sciences postdoctoral researcher Maxwell Lechte, delves into the environmental conditions from about 700 million years ago. During that time, Earth was transformed into a massive snowball; the planet s surface became entirely or nearly entirely frozen, and the oceans were cut off from oxygen.

Lechte and his colleagues travelled to Australia, Namibia, and California to study rocks left behind by glacial deposits in those regions.

The study of those iron-rich rocks helped researchers estimate how much oxygen existed in the oceans during that era the goal was to better understand the effects this would have had on marine life, including the earliest animals, like simple sponges.

While much of the oceans would have been uninhabitable during this period due to a lack of oxygen, the evidence showed there was a critical supply of oxygenated meltwater in areas where the grounded ice sheet began to float, Lechte explained.

"This trend can be explained by what we call a glacial oxygen pump ; air bubbles trapped in the glacial ice are released into the water as it melts, enriching it with oxygen," he said.

Until now, it was thought that oxygen-dependent life forms might have been restricted to meltwater puddles on the surface of the ice. Lechte s study points to new evidence of oxygenated marine environments that could have led to greater biodiversity.

"The fact that the global freeze occurred before the evolution of complex animals suggests a link between Snowball Earth and animal evolution. These harsh conditions could have stimulated their diversification into more complex forms," he said.

Lechte s study was published by Proceedings of the National Academy of Sciences of the United States of America.
Read more on CTVnews
News Topics :
Similar Articles :
How did life survive the most severe ice age A McGill University led research team has found the first direct evidence that glacial meltwater provided a crucial lifeline to eukaryotes during...
Researchers in the Department of Earth Sciences at Syracuse University have confirmed that rising oceanic and atmospheric oxygen levels co evolved with marine life hundreds of millions of years ago. advertisement...
Imagine Earth completely covered in ice. While it s hard to picture all of today s oceans and land masses obscured with glaciers, such an ice covered version of the planet...
Grand Canyon stock image . Max Planck researchers found 635 million year old molecules in rock samples from the Grand Canyon, most likely from predatory plankton. The microorganisms probably prepared the soil...
A team determined the chemical composition of ancient rocks to find there was about 0.1 of the oxygen levels present compared with today. The researchers . Why complex life took...