
Life got preserved in zircon for geochemists to find
A new paradigm shifting study was published these past few days, that says life appeared on Earth 300 million years before we thought it did.
Originally, scientists argued that life sprang up on earth some 3.8 billion years ago. It took a very long time to evolve into the single cell or multi cell organisms we know today. Humans, for example, only appeared somewhere around 200 000 years ago.
However, it seems that complex life took even longer to develop than we thought, since new discoveries show that, actually, it made its first appearance 4.1 billion years ago.
Geochemists belonging to the University of California have discovered organisms that were present on earth at that particular time. They say that the start of life was almost instantaneous back then and, given the fact that it had the right conditions to do so, it began evolving very quickly.
The evidence that they found are rock fossils encased in zircon. Zircon is a mineral formed by magma, which has the amazing quality of preserving whatever it finds in its way, in exactly the same way it found it. And seeing as the earth was a volcanic mass of rock in the beginning, after it formed as a planet, it had plenty of magma and, thus, plenty of zircon.
A good example for us to understand what the geochemists found would be the tiny mosquito from Jurassic Park. It’s the same, just that, this time, it’s with fragments of stone. The mosquito was encased in amber, their stones are encased in zircon.
The geochemists performed tests that allowed them to study the molecular and chemical composition of what they found. In this way, they were able to determine the fact that life, even in such a rudimentary state, did indeed exist at that particular point on earth.
The discovery that they made is important for two reasons. First because it sets back our planet’s history timeline by 300 million years and changes chronologically the appearance of life to 4.1 billion years ago. Secondly, it also proves that the earth was different than we thought back then.
Originally it was scientifically believed that the earth, being so young, was a very inhospitable, hot and dry place, that could not have sustained life in any way. As it turns out and as these geochemists from California prove, we were wrong about that. Our planet was capable of mothering life even then.
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