The Formation of the Earth
Earth wasn’t always the blue planet full of life we see today. In fact, when it formed from a mixture of gas and dust around 4.6 billion years ago, it would have been drastically different.
Source: Wikimedia
Due to its infancy, Earth would have been extremely hot as it was comprised mostly of molten magma. However, over the course of millions of years, it slowly cooled, and vital oceans of liquid began to appear.
Theories of Life on Earth
While it’s proven difficult to say with certainty when life truly began on Earth, scientists have gained credible insight into the question, with many theories being proposed over the past century.
Source: Wikimedia
As researchers have only discovered fossils dating back to around 3.7 billion years ago, this is often the date ascribed to the origin of life on Earth. However, a fascinating new study may reutilize our understanding of early life on our planet.
Researchers Suggest Life Began Much Earlier on Earth
Despite the dating of fossils, researchers have been adamant that life began several hundreds of millions of years before the earliest fossils.
Source: Wikimedia
However, according to the University of Chicago, “life may have emerged repeatedly, only to be snuffed out by catastrophic collisions with asteroids and comets.” Now, researchers believe they finally have evidence to suggest that life blossomed much earlier than previously anticipated.
Life Begins on Earth Shortly After its Formation
A team of international researchers led by the University of Bristol has proposed a shocking theory: Life may have flourished on Earth less than a few hundred million years after the planet’s formation.
Source: Wikimedia
The scientists shared the results of their study in the journal Nature Ecology & Evolution, which investigated the Last Universal Common Ancestor (LUCA).
What is the Last Universal Common Ancestor?
LUCA, a term used in evolutionary biology, refers to a hypothetical organism from which all cellular life on Earth directly descends.
Source: Wikimedia
LUCA includes single-celled organisms such as bacteria, plants, shellfish, dinosaurs, and modern humans. Essentially, LUCA is considered the hypothetical tree of life for Earth.
The Earliest Living Cell
The study’s authors explain that they began by comparing the genes of various living species, attempting to discern any mutations that occurred over their long history.
Source: Wikimedia
Then, they aligned the genetic timelines with known fossils, leading to their theory that LUCA, the first living cell, was present on Earth around 4.2 billion years ago, around 400 million years after our planet’s formation.
Scientists Shocked by Results of Test
Dr. Sandra Álvarez-Carretero, from the University of Bristol’s School of Earth Sciences, expressed her surprise at the study’s findings, stating, “We did not expect LUCA to be so ancient.”
Source: Wikimedia
She continued, “However, our results fit with modern views on the habitability of early Earth.”
Tracing Modern Species Back to LUCA
The team of researchers then modeled LUCA’s biology throughout, maliciously examining the characteristics of species found in the modern era and tracing their lineage back to LUCA.
Source: Freepik
“The evolutionary history of genes is complicated by their exchange between lineages,” explains lead author Dr. Edmund Moody. “We have to use complex evolutionary models to reconcile the evolutionary history of genes with the genealogy of species,” he wrote.
LUCA’s Genetic Fingerprint Remains Present in Modern Species
What truly fascinated researchers involved in the study was how the genetic fingerprint of LUCA remains present in a diverse range of species found throughout the world.
Source: Wikimedia
“One of the real advantages here is applying the gene-tree species-tree reconciliation approach to such a diverse dataset representing the primary domains of life Archaea and Bacteria,” said study co-author Dr. Tom Williams from Bristol’s School of Biological Sciences.
Complex Organisms on Earth Billions of Years Ago
Co-author Professor Davide Pisani detailed other aspects of the study, suggesting LUCA may have been a complex organism.
Source: Wikimedia
“Our study showed that LUCA was a complex organism, not too different from modern prokaryotes, but what is really interesting is that it’s clear it possessed an early immune system, showing that even by 4.2 billion years ago, our ancestor was engaging in an arms race with viruses,” he said.
New Study Revolutionizes Our Understanding of the Emergence of Life on Earth
The new study has the potential to revolutionize our understanding of the emergence of life on Earth, inspiring hope for significant breakthroughs in future investigations.
Source: Wikimedia
“The findings and methods employed in this work will also inform future studies that look in more detail into the subsequent evolution of prokaryotes in light of Earth history, including the lesser studied Archaea with their methanogenic representatives,” added co-author Professor Anja Spang.