Octopuses are known to be intelligent, advanced creatures, able to create their own shelter, change color in an instant and even adapt well to climate change.
In a new study, a group of 33 international scientists suggest these unique traits may have an unearthly origin. They investigated the theory that octopuses may have evolved from life forms that came to earth on ancient comets.
This isn’t a new concept. Scientists have been grappling with the origins of life on our planet for centuries. And this study adds an intriguing look into the theory of panspermia, that suggests the evolution of life on Earth has, and continues to be, influenced by the arrival of organisms from space.
The study has faced some criticism, but the scientists have also supported their claims with well-established research. Let’s take a closer look at their findings.
THE THEORY OF PANSPERMIA
In the 1980s, astronomer Fred Hoyle teamed up with astrobiologist Chandra Wickramasinghe to propose that life didn’t originate on earth. In fact, life was seeded on our planet by comets carrying space-hardy bacteria, viruses and perhaps even fertilized eggs and plant seeds. This concept is scientifically known as “panspermia”.
The earliest microbial life found on Earth was discovered in Canadian rocks and is estimated to be about 4.1-4.23 billion years old. This was during the Hadean epoch, when the earth was still forming its core and crust, as well as its atmosphere and oceans. Our planet had frequent and violent collisions with asteroids and comets during that period, and the surface was still extremely hot and unstable.
The study’s researchers propose that it was impossible for life to have formed on Earth during this time. The first microbes found in Canada were most likely delivered by comets and meteorites that impacted with our planet, and these microbes went on to become the basis of terrestrial life on Earth.
WHAT CAN ACTUALLY SURVIVE ON A COMET?
Comet-hopping life forms may sound far-fetched, but research is starting to show this may be a distinct reality. Evidence has found that comets would have contained vast amounts of water in their interiors when they were first formed billions of years ago at the dawn of our solar system. These protected, watery environments would have provided ideal conditions for early bacteria and viruses to grow and multiply.
The discovery of a wide variety of ancient organic particles in comets also supports this theory. Organic particles are important precursors for the creation of molecules that are the foundation of life, such as sugars, amino acids and DNA bases.
Once comets had cooled down and after millions of years in space, evidence suggests the primitive bacteria and viruses living on them became embedded in rock, carbonaceous material or ice. This effectively protected them from the intense radiation and sub-zero temperatures encountered in space.
Although not proven, it is also possible that more complex life forms, such as fertilized eggs and plant seeds, could also have survived in similar conditions.
Masters of disguise – Mediterranean Octopus
WHAT OCTOPUSES CAN TELL US ABOUT EVOLUTION
Octopuses are actually related to slugs and snails. They belong to a group of mollusks known as cephalopods that developed about 500 million years ago during what’s known as the Cambrian Explosion. This was a time when life in the earth’s oceans went through a dramatic stage of diversification and evolution, and most of the ancestors of modern life were born.
The new study, titled “Cause of the Cambrian Explosion – Terrestrial or Cosmic?”, investigated panspermia and how it may relate to the Cambrian Explosion, and the rise of life forms like octopuses. They made a few important conclusions.
1. Virus-bearing comets fueled the Cambrian Explosion.
Viruses are the smallest living organism on earth, and they reproduce by attaching themselves to a host cell in another living organism and inserting their own genetic material into the cell. This changes the genetic structure of the host cells, which can cause disease in the host.
This also means that a viral infection can alter the host’s genetic code, and potentially change its course of evolution. Retroviruses are a specific type of virus that first appeared and multiplied just before the Cambrian Explosion.
And the researchers believe these retroviruses came from cometary bombardment the Earth was experiencing around the same time. As the comets broke up and left debris trails in the Earth’s atmosphere, dormant retroviruses were released and spread across our planet’s surface.
This wide-spread introduction of new genetic material in the form of viruses affected the development of life in our planet’s oceans, and potentially all land-dwelling life forms that came later.
2. Octopuses appeared too abruptly to have evolved on Earth.
The introduction of interstellar viruses may have increased the genetic diversity of life on our planet, but octopuses have some unique genetic traits that simply don’t make sense from an evolutionary stand point.
Genetically, octopuses are significantly different than most other life forms on Earth. Their large brains, sophisticated nervous systems, flexible bodies and ability to instantly switch color and shape are still very unique compared to other modern life forms.
And these striking traits appeared very suddenly on the evolutionary scene about 270 million years ago. The research group concluded that this sudden “great leap forward” would be impossible in such a short time frame.
“Thus the possibility that cryopreserved squid and/or octopus eggs, arrived in icy bolides several hundred million years ago should not be discounted,” the researchers say.
HOW DOES THIS RELATE TO LIFE ON EARTH TODAY?
We may never know whether or not octopus eggs actually arrived on Earth from outer space, but the theory of panspermia does hold the potential for a radical shift in our world view.
The research group concluded their study by discussing the need to change from our outdated view of life originating exclusively on Earth to one incorporating “cosmic biology,” which recognizes the scientific evidence that life on our planet may have been, and continues to be, influenced by organisms that arrive from outer space.
They also point out the vast number of Earth-like planets and other life-friendly planetary bodies that exist in our galaxy, and the potential for billions of exchanges of material between them through meteorites, cometary bolides and even space dust.
“One is thus forced in our view to conclude that the entire galaxy (and perhaps our local group of galaxies) constitutes a single connected biosphere,” the researchers write.
What do you think? Is Earth part of an intergalactic web of life? Or are we alone in the universe? Please share your thoughts in the comments!
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