FACT CANNON: Blowing big holes in entrenched thinking.

Evolution From Space

Hopefully you’ve all read FACT CANNON #5: The Origin of Life – Panspermia and Cosmic Ancestry, which gives an overview of Sir Fred Hoyle and Chandra Wickramasinghe’s wonderful 1981 book ‘Evolution From Space’. This arresting book gives an engrossing and highly plausible explanation of cometary panspermia, the mechanism which may have spread life across the universe at large. It also explains how inter-related this unimaginable multitude of life forms is likely to be.

As I said in that post, I’ve done some of my own internet research on panspermia, mainly to satisfy my own curiosity around the topic, although it’s also been interesting to see how well new evidence has stacked up in support of Hoyle & Wickramasinghe’s hypothesis over the intervening years.

Spoiler alert: Yes, it’s rather well!

The bulk of this post is about research into extremophiles that has taken place since the book was published, as I believe this is the area that lends the greatest weight to the hypothesis. As far as I can tell, the information presented here is generally established fact, although some is a little controversial, but it should all be verifiable from internet searches or the links I’ve provided.

Terrestrial Extremophiles

In line with Hoyle and Wickramasinghe, my understanding is that natural selection will only give rise to adaptations that give a survival advantage in an organism’s current environment. I don’t think there’s anything controversial in this statement, but I’m open to correction here. Anyway, on this basis any particular ability or characteristic expressed by a species means that at some stage that animal must have lived in an environment that requires those characteristics for survival. This got me thinking about extremophiles. For me, these creatures, when viewed alongside the supremely well-established theory of natural selection, are a very firm indication of the reality of panspermia.

Simply put, and in the words of Wikipedia, an extremophile is an organism that thrives in physically or geochemically extreme conditions that are detrimental to most other life on Earth. Wikipedia lists 18 subcategories of extremophile organism, including:

• Cryptoendoliths (live in rocks)
• Hyperthermophiles and Psychrophiles (can survive extremes of hot and cold)
• Oligotrophs (can live with very little nutrient material)
• Piezophiles (live under high pressure)
• Radioresistant organisms (can tolerate high levels of ionising radiation)
• Xerophiles (live in extremely dry conditions)

These are often micro-organisms, e.g. bacteria or archaea, but also sometimes lichen, fungi or the perennial favourite, tardigrades. All have evolved to be able to colonise radical terrestrial environments where few other species can survive. They show us that life can get a foothold absolutely anywhere, from solid rock miles underground, to super-heated, 121°C water in the walls of deep sea hydrothermal vents. They can be buried deep in multi-millennia old Greenland glaciers, thrive in the driest deserts, and in the highly pressurised and nutrient poor waters of Lake Vostok miles beneath the surface of Antarctica.

We also have radiation resistant plants, worms and insects thriving on a uranium-rich hillside in Brazil; and, more remarkable still, fungi feasting on radiation in the melted down reactor core of the Chernobyl nuclear power plant.

Extremophiles In Space

Although the capabilities of the extremophiles discussed above illustrate the remarkable tenacity and near ubiquity of life on Earth, our real interest is in organisms that are able to survive in environments not found on this planet. Some examples:

• Streptococcus Mitis
Although controversial, NASA reported that this organism, which is normally found in your mouth, survived for 3 years on the surface of the moon in a colony on the camera of the Surveyor 3 probe, which was brought back to Earth for examination by the Apollo 12 mission in 1971.

• OU-20 Sample Bacteria, aka the Beer Bacteria
Taken from a cliff in Devon, England, in 2010, these bacteria survived for 553 days on the outside of the International Space Station as part of the ESA BIOPAN research program. They would have been exposed to extreme shifts in temperature, cosmic rays and unshielded ultraviolet light, hard vacuum, and as a consequence total dehydration. Not an environment generally experienced on Earth, even during a British summer!

• Thermoanaerobacter siderophilus
This bacteria was used by Russian scientist Alexander Slobodkin to understand whether bacteria can survive re-entry into a planetary environment. Colonies of the bacteria were embedded in centimetre thick basalt discs which were fixed onto the outside of the Foton-M4 space probe launched in 2014. Reportedly the bacteria remained viable after 45 days in orbit and re-entry at a velocity comparable to that attained by meteorites, reaching temperatures high enough to actually melt the basalt.

• Bacillus Sphaericus
In 1995, Borucki and Cano reportedly extracted viable bacterial spores related to Sphaericus from the gut of an extinct bee embedded in Dominican amber aged between 25 and 40 million years. On a similar note, bacterial spores in excess of 250 million years old have also been reportedly extracted and cultured from salt crystals extracted from the air intake shaft of the Waste Isolation Pilot Plant in New Mexico, 609 metres below ground level. This extreme longevity would be extremely useful for anything floating in interstellar space for countless millennia.

So, we are already aware of numerous organisms that could survive in environments in outer space and on other planetary bodies within the solar system, which could also survive the extreme heat experienced in atmospheric re-entry and the physical extremes that would be experienced during a meteor impact event of sufficient force to eject planetary material into space. See Wikipedia ‘List of microorganisms tested in outer space’ for more examples.

All these species are living here on Earth where many of these environments do not exist, and, very importantly, have never existed. So, using just the theory of natural selection, it is not such a stretch to infer that they have the capability to survive in these environments for the very reason that their survival as a species has depended upon adaption to these environments in the past. On this basis wouldn’t it be reasonable to propose that these organisms have very likely evolved on other planetary bodies or in space where these conditions do exist, and that either the organisms, or their genetic material, have arrived on Earth via cometary seeding or meteoric impact? It seems likely that space is permeated with unimaginably colossal clouds of these tiny packages, supremely well evolved to carry their cargo of genes to the edges of the universe.

Paracoccus Denitrificans

The jewel in the crown of this train of thought is Paracoccus Denitrificans.

Paracoccus Denitrificans has recently been tested for its resistance to extreme gravity. This was performed in 2011 using an ultra-centrifuge in a Japanese lab, by Deguchi and Shimoshige. It seems that P Denitrificans can survive gravity more than 400,000 times that found on earth, and remarkably it is also able to exhibit cellular growth under these conditions. These are gravitational conditions found on sub-stellar objects, or in the shock waves experienced by planets vaporised by supernovae. Perhaps P Denitrificans has been propelled across the depths of interstellar space, from star system to star system, at around 10% of the speed of light, borne along on the bow wave of a detonated star. What is even more mind-blowing about P Denitrificans, is that it is a candidate for being the originator of mitochondria, the tiny power plants that provide energy in the cells of most living organisms.

In case you were wondering whether material from supernovae ever reaches the Earth, scientists from the University of Munich have recently detected Iron-60 ejected from supernovae in deep-sea sediment in the Pacific Ocean. See Near-Earth Supernova.

So You Still Believe Life Originated On Earth? Really?

Obviously this evidence is heavily in favour of Hoyle and Wickramasinghe’s hypothesis of cometary panspermia. But let’s put this to one side for a minute, and consider a different problem. Conventional science tells us that abiogenesis, the emergence of life from non-living material, occurred on ancient Earth. Putting aside Hoyle’s objection to the extreme unlikelihood of abiogenesis actually happening anywhere at all in the universe, I have a major problem with the supposition that an event of this magnitude would ‘just happen’ to take place solely on our planet. In a ‘warm little pond’, or maybe at a hydrothermal vent, or deep underground, on Earth. Earth, which is one of 20 or so potential candidate planetoids in our solar system, itself one of 250 billion star systems in the Milky Way, itself one of 150 billion galaxies in the universe. Hmmm… Now you put it that way, taking into account the pure unlikelihood, and all of the extremophile evidence set out above, it does seem just a touch unlikely… Just a little bit like ‘the Sun goes around the Earth’. Wouldn’t it take some pretty strong faith, almost at religious levels, to believe something so improbable?

Interestingly, recent research has suggested that the LUCA (Last Universal Common Ancestor) of all life on Earth, the organism that we have all descended from, was likely very closely related to a thermophile Clostridium bacteria (itself an extremophile) that probably lived in an extreme environment around a hydrothermal vent. So did this appear via auto-evolution of self replicating molecules leading to an improbable abiogenesis on Earth, or did it arrive via cometary delivery, as a bootstrap for life on the planet - a gift from a universe already crawling with life? The truth is that we don't know yet, but new evidence is arriving all the time, and the cometary panspermia hypothesis is looking increasingly compelling.

Final Thoughts

Ok, I’m going to stop here for now. I’ve got quite a few more thoughts on this subject that delve a little deeper into the realms of conjecture, but I’m going to save that for a follow up post which won't be for a couple of weeks for reasons beyond my control. In the meantime, you might want to give ‘Evolution From Space’ a read, or check out Chandra Wickramasinghe’s excellent 2014 book ‘The Search For Our Cosmic Ancestry’. I’ve now read about half of this book, and it gives a much more thorough update of the many advances in supporting evidence. I’ve really just scratched the surface here.

Anyway, let me know how you feel about this post. Your feedback is always very much appreciated.

Inspiration:

‘Evolution From Space’ – Sir Fred Hoyle & Chandra Wickramasinghe
https://en.wikipedia.org/wiki/Panspermia
https://en.wikipedia.org/wiki/Fred_Hoyle
https://en.wikipedia.org/wiki/Chandra_Wickramasinghe

Previous editions of FACT CANNON:

FACT CANNON #5: The Origin of Life on Earth – Panspermia and Cosmic Ancestry
FACT CANNON #4: Pholcus – The Other People Who Live In Your House
FACT CANNON #3: The Sad Tale of Paul The Psychic Octopus
FACT CANNON #2: How Frankenstein Was Born In The Fiery Heart of A Super Volcano
FACT CANNON #1: Romanesco Broccoli, A Reality-Bending Vegetable

Image Credits: All images released free of copyrights under Creative Commons CC0 from Pixabay

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