A new study has found that the erosion of great mountain ranges may have provided critical oxygen and nutrients that spurred the development of the earth’s first organisms.
“There’s nothing like these two ranges today,” lead author and geochemist Ziyi Zhu said in a release on Feb. 3.
Zhu and colleagues made the discovery by tracking traces of zircon with low lutetium content, which is found only in the roots of high mountains.
They found the largest of these supermountains only formed twice—the first between 2,000 million and 1,800 million years ago and the second between 650 and 500 million years ago when tectonic plates crashed together.
These two periods correspond with major advances in the development of living beings in history.
“What’s stunning is the entire record of mountain building through time is so clear. It shows these two huge spikes: one is linked to the emergence of animals and the other to the emergence of complex big cells,” said Jochen Brocks, co-author and professor of the Earth Sciences at the Australian National University.
The first ancient formation is called the Nuna Supermountain.
“It coincides with the likely appearance of eukaryotes, organisms that later gave rise to plants and animals,” Zhu said.
“The second, known as the Transgondwanan Supermountain, coincides with the appearance of the first large animals 575 million years ago and the Cambrian explosion 45 million years later when most animal groups appeared in the fossil record.”
These mountains may have also boosted oxygen levels in the atmosphere, needed for complex life to develop.
“The increase in atmospheric oxygen associated with the erosion of the Transgondwanan Supermountain is the largest in earth’s history and was an essential prerequisite for the appearance of animals,” Zhu said.
Their erosions also provided oceans with nutrients such as phosphorous and iron, essential for the growth of marine plants which compose the basis of our food chain.
“The slowing of evolution is attributed to the absence of supermountains during that period, reducing the supply of nutrients to the oceans,” co-author professor Ian Campbell said.
The scientists have a name for this period of tranquility.
“The time interval between 1,800 and 800 million years ago is known as the Boring Billion, because there was little or no advance in evolution,” Campbell said.
“This study gives us markers, so we can better understand the evolution of early, complex life.”
