Cosmology: snowball Earth advanced life (Introduction)

by David Turell , Saturday, August 28, 2021, 19:30 (1182 days ago) @ David Turell

Another study in China:

https://www.sciencedaily.com/releases/2021/08/210827121450.htm

"Around 650 million years ago, the Earth entered into the Marinoan glaciation that saw the entire planet freeze. The 'Snowball Earth' impeded the evolution of life. But as it warmed, biotic life began to flourish. A research team has now analyzed rock samples from China to tell us more about this transition.

"A research team from Tohoku University has unveiled more about the evolutionary process of the Marinoan-Ediacaran transition. Using biomarker evidence, they revealed possible photosynthetic activity during the Marinoan glaciation. This was followed by photosynthetic organisms and bacteria entering a period of low productivity. However, as eukaryotes expanded during the early Ediacaran period, they blossomed.

***

"Bacteria and eukaryote biomarkers demonstrate that bacteria dominated before the glaciation, whereas steranes/hopanes ratios illustrate that eukaryotes dominated just before it. However, the relationship between the biosphere changes and the Marinoan glaciation is unclear.

***

"Kaiho believes we are one step closer to understanding the evolutionary process that occurred before and after Snowball Earth. "The environmental stress of closed ocean environments for the atmosphere followed by high temperatures around 60°C may have produced more complex animals in the aftermath." Their findings show that bacterial recovery preceded eukaryotes' domination."

Comment: The Ediacaran diversity that appeared is very simple compared to the later Cambrian Explosion animals. This shows part of the evolutionary process that finally created our current biosphere.