Australasian Science: Australia's authority on science since 1938

Mountains Drove Bursts of Evolution and Extinction

The oldest life on Earth is still going strong today. Stromatolites are communities made up largely of blue-green algae. This image shows a living colony of stromatolites at Shark Bay, Western Australia. Credit: Ken McNamara

The oldest life on Earth is still going strong today. Stromatolites are communities made up largely of blue-green algae. This image shows a living colony of stromatolites at Shark Bay, Western Australia. Credit: Ken McNamara

By Ross Large, John Long & Indrani Mukherjee

Bursts of evolution and mass extinction events coincide with mountain-building events that have influenced nutrient levels in the oceans.

The full text of this article can be purchased from Informit.

The oceans became the cradle of life almost 4 billion years ago, and have been home to all life on Earth for roughly 90% of the time since life first appeared. Prior to about 470 million years ago, all life on Earth lived in the oceans.

We can trace single-celled organisms back to about 3.54 billion years ago and complex organisms (eukaryotic cells with a nucleus) to 2 billion years ago. Complex multicellular animals (metazoans) appeared at least 580 million years ago, but the most significant evolutionary event leading to all modern animal phyla occurred during the Cambrian explosion 550–520 million years ago. Our back-boned fishy ancestors only invaded land about 370 million years ago, enabling humans to ultimately evolve from fully terrestrial tetrapod ancestors.

Life in the oceans has always required nutrient trace elements to survive and evolve. These include iron, phosphorus, nickel, cobalt, molybdenum and selenium. These and other “essential trace elements” were so...

The full text of this article can be purchased from Informit.