It’s not often that I get to announce a major breakthrough in astrobiology that literally
changes everything. This particular one has implications on ¾ of the content on this
channel and is simply stunning. A team of scientists at the Foundation for Applied Molecular
Evolution have literally cracked the nut of one of the greatest mysteries in science and
abiogenesis. In fact, it answers the first question in the series of how life arises.
Their model involves RNA, and how RNA comes to be in nature. One of the major hypothetical
scenarios on how life arose on earth is known as the RNA world hypothesis. It goes like
this, scientists suspect that the first stage of abiogenesis was the formation, somehow,
of RNA. RNA molecules can be self-replicating as molecules, which might have been, and in
fact was if this research is confirmed, the first step towards the evolution of life and
DNA. But the huge question has always been how did RNA form, and was it a difficult process
that isn’t likely to happen often in the universe, or was it a fairly straightforward
process that probably happens often.
I’m happy to say, if this research is confirmed, It turns out that it’s so easy you can do
it in a high school science class. RNA would become a very common type of molecule in the
universe to the point that any terrestrial planet with volcanism has it. And while a
molecule of RNA isn’t life, it’s merely a molecule that can store information, it
dramatically increases the chances of microbial life in the universe. We don’t yet know
where the process of abiogenesis goes after the occurrence of RNA, but there are theories
and work is being done that suggest that while complicated, it’s somewhat straightforward.
How it happens involves volcanic glass. Simple volcanic glass folks. All that happens is
nucleoside triphosphates percolate through volcanic glass, and out come RNA molecules
with 100 to 200 nucleotides in length. That’s it. Borate, which is very common in basaltic
rock, moderates the reactions. Nickel, delivered by the constant meteorite impacts of the late
heavy bombardment, plays a role as does phosphate, which is found in volcanic glass. You just
need water percolating through providing the solvent.
This process is so simple, and volcanic glass so common on earth, that RNA was probably
occurring all over the planet in subsurface wet conditions. Previous work by the same
team showed how nucleosides are formed, and that too was straightforward. In short, the
landscape of moving towards Darwinian Evolution is clearing, and it’s turning out to be
far simpler than anyone had ever imagined.
If confirmed, this finding has far reaching implications. The first is for Venus and Mars.
They too would have almost certainly had RNA spontaneously forming under the same conditions
as earth. In fact, at Mars, below the surface in aquifers it may still be occurring and
it’s probably not a bad idea to check our meteorite collections for RNA in specimens
of known Martian origin. Further future experiments on Mars searching for life might incorporate
methods for testing for RNA in subsurface aquifers.
It also changes the playing field for life in the solar system in general. Places that
were previously seen as unlikely for life, come on the table. Two noteworthy candidates
come on the table here. First is Io. Io is wildly volcanic and certainly has the needed
glass and materials. It also once had as much water as Europa or the other Galilean moons
of jupiter. Some of this water may remain subsurface, which despite being actively volcanic
may sport pockets of habitability below its surface.
The other is the moon. Again, the moon has no shortage of volcanic glasses and may have
had a period of habitability, or a layer deep enough and warm enough for water, where abiogenesis
may have occurred. As to the universe at large, if the trend towards abiogenesis being really
easy continues, then it will soon be safe to say that the universe must teem with microbial
life. It would be everywhere, with multiple bodies in star systems hosting it. And with
over 90 percent of stars in the observable universe being habitable, and a great many
of them sporting terrestrial planets, the numbers become staggering. It becomes possible
that microbial worlds and moons may outnumber the stars themselves.
And that creates the conditions for civilizations to arise. Another recent discovery was related
to how complex life comes about. This was known as the Prokaryotic to Eukaryotic leap,
and it seemed extremely unlikely and a very strong great filter. The reason is that the
situation on its face seemed that the leap required an organism to absorb another organism
and incorporate it without digesting it. That seemed to be asking a lot and it might explain
why it took life on earth almost 2 billion years for this leap to occur.
Recent findings however show that it may not have occurred that way and in fact was a product
of microbial symbiosis. In this case, you just need to wait long enough for a symbiotic
situation to develop and the leap occurs straightforwardly. It’s also a case that earth might simply
have been a late bloomer in this regard, and there may be cases where the leap happens
far earlier on most exoplanets and evolution gets fast tracked. This scenario both raises
the likelihoods of civilizations arising, but also offers the option that it may happen
earlier on most exoplanets and that earth was just slow, defeating the argument that
maybe we’re the first civilization in the galaxy.
But then there is the pesky great silence. This scenario leads to alien civilizations
being very common, so where are they? It’s also possible that earth truly was early in
the game for making the leap, and that as a rule while the leap happens regularly, it
usually does it on longer time scales and that while occurrences of life are everywhere,
very few of them have made the leap yet. This leads to a universe where the occurrence of
intelligence radically increases as time passes.
Another area where this model has implications is in the area of astrovirology. This is an
area of astrobiology that’s almost as spooky as the idea of hostile alien civilizations.
Viruses are believed to have arose and evolved alongside life. Some of the most common viruses
we deal with are based on RNA. The viruses that cause colds, influenza, Hepatitus C,
Ebola, polio, rabies, and even Covid are RNA viruses, and may trace their roots all the
way back to RNA forming in lava glasses billions of years ago. But if that’s the case, and
life and viruses co-evolve, it may be that’s the rule of the universe. And it’s unsettling.
Viruses on earth vastly outnumber organisms, and it would imply that we do not live in
a universe of life per se, that is secondary, but in a universe absolutely dominated by
viruses. While that may seem a bit disconcerting, it’s best to remember that viruses tend
to be very specific and can’t infect every cell on the planet, just those of their specific
hosts. Alien viruses would have no commonality at all, and we’d likely be immune to the
vast majority of them, as we are here on earth.
That’s unless a virus can generalize. This one is a long shot, everything we know about
viruses suggests that this scenario is highly unlikely, but it has been suggested in the
annals of astrobiology. In the case of a dying world, such as Mars during the final days
of it being a water world, where viruses could evolve to attack any cell they find. If so
it may be possible that dangerous viruses that can infect all life might be present
on worlds like Mars and should be checked for before returning samples or setting foot
on them. Again, unlikely, but there are protocols in place for Mars sample return missions to
check just in case.
Yet another area where this model has implications is in the concept of a shadow biosphere. Here
we would have a second genesis of life that co-exists with an original genesis of life.
How the model works here is that it may be that RNA is forming constantly on earth spontaneously
under the conditions of the model. This raises the chances of abiogenesis occurring all the
time, and that as new life arises, the first occurrence of life, our kind of life, snuffs
it out. But it’s also possible that there is a separate microbial biosphere on this
world that we simply haven’t detected because our means of detecting microbes is too skewed
towards our type of life.
This also offers a novel way to test the model. Find the conditions where RNA might be forming
and check and see if its there. It’s possible that new RNA is formed constantly on earth,
and has been since very early in the history of the planet. But there are still questions
within the RNA formation model. The work shows ultimately that very complex RNA molecules
can be formed chemically from very simple organic molecules that are almost guaranteed
to have been present and forming in earth’s atmosphere during the advent of life.
The model shows that very complex RNA molecules can form that are long enough to allow for
evolution to begin, and true life to arise. But questions arise about why all life on
earth uses only one of two possibility chiralities along with specific questions about nucleotide
linkages. But over all, it seems that abiogenesis was not as complex of a process as has been
suggested. Some of the models of how life could have arisen were getting increasingly
unlikely to have happened on earth, a phenomenon where something in science proves unexplainable
forcing the theories in ever more speculative and often unlikely territory. Then something
comes along, like this model, that shows that the answer was simple all along, it’s just
that no one had thought of it. But within all of this, there is a rather eerie point.
If abiogenesis proves easy as work on understanding it progresses, then the great silence gets
even more deafening than it already is.
Thanks for listening! I am futurist and science fiction author John Michael Godier currently
a little spooked. If volcanic glasses were the birthplace of life, it’s rather strange
because among the first materials humans fashioned into tools is volcanic glass, so it could
be said that it is also the birthplace of technology making it in some ways the most
important substance in the universe common to all civilizations both at abiogenesis,
and the moment they reach technology. Eerie and be sure to check out my books at your
favorite online book retailer and subscribe to my channels for regular, in-depth explorations
into the interesting, weird and unknown aspects of this amazing universe in which we live.