The Snowball Earth hypothesis states that Earth was almost completely frozen 650 million years ago. The beginning of the Ediacaran Period was marked by the change in atmosphere. Multicellular life was present on the planet for the first time in the Ediacaran Period. The more well-known Cambrian Period was when more complex life emerged and flourished.
It was the first mass extinction in the history of the planet.
Why did it happen?
Shells and skeletons from the Ediacaran wouldn't appear until after the Cambrian Period. There are a lot of fossils of Ediacaran life in some places. The Ediacara Hills are in South Australia and are one of the locations.
Life increased in complexity and became multicellular. The Ediacaran biota was anchored in place. Even more complexity would have to be created by evolution. The life was anchored to the ocean's bottom. The life forms at the time looked like worms and mudbags. According to some research, Ediacaran lifeforms may have absorbed the sea's vitamins and minerals through their skin.
The Earth was not the same during the period. Pannotia broke apart during the time when the Gondwana supercontinent was forming. The ocean became more oxygenated and deeper. Oxygenation made more habitats for oxygen-loving life forms. During the Ediacaran, life became more complex and spread around the world.
Almost all of the unique Ediacaran biota vanished after something happened. The Ediacaran was followed by the Cambrian Period. The body plans for animals now come from the Cambrian. After the extinction of the Ediacaran, evolution had a blank slate to try again.
According to the authors of a new paper, the End-Ediacaran Extinction was caused by a decrease in oxygen availability. The first major animal extinction in the White Sea-Nama transition was caused by environmental drivers. Scott Evans is a researcher in the department of geosciences at the Virginia Tech College of Science. Evans is an author and co-author of several papers.
According to some research, life is to blame for the extinction. New lifeforms behaved differently as they evolved. The phenomenon of "ecosystem engineering" is a result of those behaviors. The proponents of this line of thinking think that mobile lifeforms appeared as the Cambrian explosion happened. The creatures of the Ediacaran were devoured by them. Evolutionary innovation, ecology and biological interactions may have caused the first mass extinction of complex life, according to a paper published in 2015.
Evans and his colleagues don't agree. Oxygen levels plummeted, leading to the extinction of 80% of Ediacaran life.
Many different types of animals were lost. Evans said that those who use significant amounts of oxygen seem to have been hit hardest. The extinction event is similar to all other mass extinctions in the geological record.
The Ediacaran biota is divided into three different fossils. The White Sea was 590–560 Ma. 541 Ma. The majority of the taxa in the White Sea are not present. It is unlikely that the lifeforms were outcompeted and replaced by other lifeforms, which is called biotic replacement.
Some of the lifeforms that disappeared during the extinction had different characteristics. That shows that an over-arching environmental characteristic has changed. The surviving creatures shared a trait.
The paper states that the preferential survival of taxa may be related to reduced global oxygen availability. Our data supports a link between Ediacaran biotic turnover and environmental change like other mass extinctions in the geologic record.
There are two extinctions attached to the Ediacaran. There was a loss of diversity during the White Sea. There was a second at the boundary between the Ediacaran and the Cambrian.
The potential sampling bias in the fossil record has been pointed out by some researchers. The team looked into the possibility of a sampling bias. They looked at the paleoenvironments and preservation modes for the fossils from the Ediacarans.
Sampling biases can't be blamed for changes in diversity.
Oxygen levels plummeted if Ediacaran life was doomed by falling levels.
The paper doesn't give an answer, but it does give some thoughts. Major drivers of mass extinctions include bolide impacts, the eruption of large igneous provinces, and/or tectonic shifts, which lead to diversity decline. The broad range of paleoecologies impacted across the White Sea–Nama extinction is consistent with the predicted effects of a catastrophe.
It was terrible for life to see something change about Earth. The Cambrian period that followed the Ediacaran was a time when life flourished again. The first representation of the modern animal phyla was in the Cambrian explosion. Life now looks nothing like that of the Ediacaran, with very few exceptions.
“Essentially, this extinction may have helped pave the way for the evolution of animals as we know them.”
Scott Evans, lead author, Department of Geosciences at the Virginia Tech College of Science.
We don't really know how this happened. The animals that go extinct seem to be responding to decreased global oxygen availability.
Is there a lesson to be learned from this?
According to Shuhai Xiao, a co-author, global warming and deoxygenation events can lead to massive extinction of animals. This work on the first extinction documented in the fossil record is one of many examples of this. The study tells us about the long-term impact of the environment on the biosphere.
The oceans will warm as Earth does. The ocean holds less oxygen. The excessive run-off from agriculture is a factor. Microbes consume more oxygen as they break down the run off. We are the ones who are responsible for the warming. The engineering is not straight forward.
The new mass extinction of animals was caused by major climate change, as with all other mass extinctions in the past, according to the study.
The development of life on Earth can be traced back to extinctions. Evolutionary designs that didn't persist past the Ediacaran extinction are represented by the fossils.
Evans said that many of the organisms appear to be experimenting with different ways to build large, sometimes mobile, multicellular bodies. Before this extinction, the fossils we find don't often fit into the way we classify animals today. The extinction may have paved the way for the evolution of animals.
The life during the Ediacaran Period was mostly immobile. The Ediacaran is sometimes referred to as the "Ediacaran Garden" The extinction of Ediacaran may have prevented the explosion from happening. There may have been no dinosaurs, no mammals, and no Homo sapiens. It doesn't seem likely that Earth would have remained in a permanent Ediacaran state.
There were five extinctions in Earth's history, the last of which took place 350 million years ago.
Mass extinctions are important steps in the evolution of life on this planet. It may have been the most important in shaping life on the planet.
All Rights Reserved © 2024
