Now it is thought that animals emerged between 1.8 billion to 600 million years ago. It’s no wonder that oxygen needed for complex life such as animals.
It was already known that oxygen levels needed to rise high enough to support complex life forms. Lower and less complex lifeforms like sea sponges can live in lower oxygen levels. But complex life like vertebrates and mammals need much higher oxygen levels.
New research shows oxygen in the oceans rose in temporary hotspots then shifted. This was seen in fossil records. Scientists have concluded that pockets of high oxygen level ocean water was first seen in the tropics then shifted to the poles. Any organisms that started to develop in the tropics were then in a challenging situation. These pockets of high oxygen moved regularly. This means that only the organisms most able to adapt and evolve were able to survive.
The conclusion made is that these shifting pockets of oxygen lead to the great diversity of animal life we now enjoy. As the oxygen level shifted new forms of animal life developed for that level. And then was forces to evolve… over and over again… creating great diversity.
Recent research suggested this process may have started as long as 3.2 billion years ago with oxygen levels beginning to soar around 2.4 billion years ago.
But it was not until between 1.8 billion and 600 million year ago that the first animals are thought to have emerged.
The work by Dr Reinhard and his colleagues now helps to explain that this was probably due to the way in which oxygen was absorbed by and dissolved in the oceans.
This research, like so many others, how much we as complex human animals need good oxygen levels to sustain our lives and thrive.
Trishah August 2nd, 2016
Posted In: Science and History