Jakarta –
Land completely or almost completely frozen about 650 million years ago, according to the Snowball Earth Hypothesis. When the atmosphere changed and the Earth warmed, our planet marked the beginning of the Ediacaran period.
Quoted by Universe today, The Ediacaran period marked the first time that multicellular life spread on Earth. This preceded the more famous Cambrian period, when a more complex life emerged, varied and developed.
In its development, life during the Ediacaran period faced mass extinction, and it was the first time on Earth. What happened?
Ediacaran fossils are quite rare because their shells and skeletons only appeared in the Cambrian period. However, some locations contain significant numbers and types of soft-bodied Ediacaran life fossils. One such place is the area named after the time, the Edicara Hills, in South Australia.
The Ediacaran period saw life increase in complexity and become multicellular. Most biota ediacarans are sessile, i.e. anchored in position.
Mobility must wait for evolution to create more complexity. The creatures at the time tended to be tubular or leaf-shaped and anchored to the sea floor.
Other life forms at the time resembled segmented worms and sedentary mudbags. According to some studies, Ediacara living creatures most likely absorb nutrients from the ocean through their skin.
More oxygen
Earth was very different during the Ediacaran period. The supercontinent Pannotia preceded the more famous supercontinent Gondwana and the Pannotia formed and melted during this period. Oceans are also becoming more oxygenated at great depths.
Oxygenation creates more habitats for oxygen-loving living things. Life evolves, becomes more complex and spreads around the world during the Ediacaran.
But something happened that caused a mass extinction and nearly all of Ediacaran’s unique biota disappeared. The Cambrian period followed the Ediacaran period and Cambrian life almost completely replaced the Ediacaran life.
Most of the body drawings of animals living today date from the Cambrian, not the Ediacaran period. The author of a scientific paper titled “Environmental Drivers of the First Great Animal Extinction Through the Ediacaran White Sea-Name Transition,” says that decreased oxygen availability led to the extinction of the late Ediacaran.
The lead author of the paper, Scott Evans, a postdoctoral researcher in the Department of Geosciences at Virginia Tech College of Science, focused on the Ediacaran period.
Several studies suggest that life itself caused the Ediacarans to become extinct. That line of thinking says that when new life forms evolve, they behave differently.
This behavior leads to fundamental changes in ecosystems, in a phenomenon called “ecosystem engineering”. Proponents of this line of thinking argue that mobile life forms emerged when the Cambrian explosion took effect.
They ate the sessile creatures of the Ediacarans and exterminated them. A 2015 paper states that the study provides the first quantitative paleoecological evidence to suggest that evolutionary innovation, ecosystem engineering and biological interactions may have led to the first mass extinction of complex life forms on Earth. Land.
But Evans and his colleagues disagreed. They say that the decrease in oxygen levels caused the extinction of about 80% of Ediacaran’s life.
“This includes the loss of a wide variety of animals. However, those whose bodies and behavior indicate that they are dependent on large amounts of oxygen appear to be the most affected,” Evans said.
“This suggests that the extinction event was controlled by the environment, like all other mass extinctions in the geological record,” he added.
Next: Falling Oxygen Levels and Lessons for Mankind
