One strange feature of our circumstances on this planet is that we stand alone as a species.
We, as homo sapiens sapiens, are the sole surviving member of our genus.
Yet, there have been others, estimates range from 12 to 14 known extinct members of the
genus homo are known to have existed, though whether some are actually separate species
is debated.
And there are probably others yet to be discovered due to gaps in the history of these species
that hint at other undiscovered species of humans.
Several things hallmark all members of the genus homo, and one would be tool use.
Even the earliest member of the genus, homo habilis, could fashion stone tools.
Homo habilis appear to have been omnivores, and one theory suggests that a high proportion
of meat in the diet of homo habilis was a major factor in brain growth driving towards
increased intelligence and eventually us.
Tool use in processing meat may have been not only an important step in human history,
but in fact was a precipitating event that allowed technological civilization to arise.
We may be here specifically because an ancestral species invented the manufacture of tools.
Had that not happened, Earth may never have hosted a technological civilization.
Not only did technology begin with that first species of our line, we inherited tool use
from our ancestors as it telescoped through the evolution of homo sapiens.
And we still use stone tools, there are medical instruments made today that make use of the
volcanic glass obsidian because of its inherently sharp edge.
Another instance here is fire, it’s thought we inherited that from homo erectus who seem
to have mastered fire at least a million years ago, if not longer.
We still use fire, indeed there are more controlled fires going on this planet right now than
there ever has been in all of human history.
One wonders how common this is among the early stages of the evolution of a technological
alien species.
Volcanic glass and suitable stone for tool making isn’t unique to earth.
If for example you want volcanic glass, you’ll find it on Mars and very likely Io and many
other formerly volcanic bodies in the solar system.
And You’ll just as likely commonly find it on exoplanets.
Given that it has an inherent use for making sharp tools, it may be a common first technology
for any species in the universe capable of planning and then fashioning it into a tool.
That may also be the case for fire.
Exoplanets with suitable atmospheres probably commonly allow for it, and the same atmosphere
that allows for intelligent life on this world, also allows for fire.
But it also has to be said that there is another somewhat spooky reality within the genus homo
for which we are the only exception.
All others went extinct.
Part of the answer to this is that some earlier humans simply disappeared into our gene pool
through interbreeding.
But some did not, and while a very incomplete fossil record for some species prevents a
picture of why they met their extinctions, generally speaking the culprit for most humanoid
extinctions ultimately was likely to be changes in climate which destroyed their niches.
Only we survived because we had a wide palate and a very advanced brain compared to the
others.
Had we gone extinct, it’s easy to imagine an earth that just continues on as it had
before the advent of humans.
It’s even possible, given that life on earth took so long, and things were so situational,
and lucky, that earth may never produce another species capable of technology.
Perhaps inhabited planets on average only get one chance shot at it, and if we were
gone early on, Earth would never have seen civilization at all even after spawning intelligent
life.
There is some evidence for changing climate being a problem for our genus.
In both the cases of Homo Erectus and Homo Heidelbergensis there is a correlating sharp
drop in global temperatures just before they disappear from the fossil record.
And the scary thing here is that had those same factors got us, the genus homo would
be every bit as extinct as the dinosaurs.
We’d have been a several million year flash in the pan on this world and after our disappearance
the world would have reverted to limited animal intelligence and evolution would have taken
a different turn.
As a result, it could be said that there almost wasn’t a civilization here at all.
This is because there is one other rather odd feature of the only surviving species
of human.
There is evidence that we ourselves came very close to extinction in the past.
It’s hard to imagine that with our enormous population of today that we were once an endangered
species, but we were.
One factor here was the number of homo sapiens early in the species' history as anatomically
modern humans.
When we first appeared as a singular species homo sapiens sometime around 315 thousand
years ago, we were rare and confined to a single continent, Africa.
But conditions early on were good.
Food seems to have been plentiful with a climate conducive to human existence.
But then something bad happened about 195,000 years ago, that would persist for over 70,000
years.
Most of Africa became uninhabitable for humans, possibly including the Olduvai Gorge, so linked
to the rise of humanity.
It’s long been suspected that there was a population bottleneck early in human history,
geneticists have found evidence of a contraction in our genome right around this time that
also corresponds to similar contractions seen in predator species in Africa around that
same time.
We all took a hit, and all humans alive today descend from that tiny group of survivors.
What caused Africa’s climate to shift so severely is related to glaciation.
Cores taken from the ocean floor show a series of events marked by oxygen isotopes that give
a picture of how the climate has varied over time.
In this case, the event is known as Marine Isotope Stage 6 and is associated with a period
of cooling and glaciation on the planet.
The effect of this would have been the expansion of Africa’s deserts, rendering much of the
continent uninhabitable.
It seems that our population contracted severely, possibly as low as less than a thousand people
left living off of shellfish and edible plants along the southern coast of Africa.
That’s it.
If something had happened to that cluster of humans in a single region that they couldn’t
weather, we’d be extinct.
It seems that only our brains allowed us to get through it, along with a whole lot of
luck.
And that’s where we can ask the question, is there something about intelligence that
disfavors survival, and that the solution to the Fermi Paradox is that first, the chance
evolution of technological intelligence may be very rare as it was on earth, and secondly
that once it does arrive it goes extinct before ever reaching even agriculture, much less
technology.
And the point can be made that even if a technological species gets lucky as we did and makes it
to a highly technological stage of civilization, can it sustain and survive its own technological
development, which is of course an open question for us.
This leads to a somewhat sad prospect for life in the Milky Way, that most alien intelligent
life can’t ever be interacted with because it lies in the fossil record of exoplanets.
We could find that intelligence is common enough, but gets taken out by a change in
climate, or never fully matures due to never hitting tool use and something analogous to
a wide and adaptable omnivorous diet like what early homo sapiens ate, and still does.
A contraction in diet options could be key, and be a great filter for intelligence for
lack of availability to develop and maintain a complex brain.
The choices become either dumb or too smart for your own good, limiting the prospects
for widespread intelligent alien life.
But then again, it always comes back to luck and a numbers game.
While sustaining intelligent technological life may be rare, it’s unlikely to be unique,
and there will always be examples where they don’t go extinct, do not have the conditions
necessary for their own extinction, and make it through to last indefinitely and colonize
their galaxy.
But that in itself leads to situations where the first civilization to do that, remains
the only one ever to arise in their galaxy.
Being first is typically a good thing, and that goes for alien civilizations.
Being the first technological civilization in a galaxy means that that galaxy is your
oyster to fully colonize and pursue a goal of becoming a Kardaschev type three civilization.
But this could come at a cost to any other species in that galaxy evolving towards intelligence.
That first civilization may simply prevent evolution on exoplanets from going that route,
after all, you never have any enemies or rivals if you’re early enough to stop them from
ever existing.
This is a variant of the notion of watcher aliens that intervene whenever a civilization
develops a sufficiently dangerous technology, as to be a threat to the galaxy at large.
Here it would be the biological equivalent of taht, where you simply don’t allow intelligence
to arise that could ever build such technologies, and the species you interact with and manage
simply live life in blissful nature never being able to conceive what technology or
intelligence actually is.
This concept is known as downshifting, and is the opposite of uplifting, or making a
species you come across more intelligent than it was.
Downshifting is the easiest, least resistance to preserve your permanent galactic hegemony.
But it has to be said that we see no evidence of this, or else we’d have been downshifted
ourselves by whatever civilization is dominant in the Milky Way.
This could suggest three things.
The first is that we’re the first civilization to achieve advanced technology and high intelligence
that didn’t go extinct, thus we will be the galactic dictator species.
The second is that no one practices downshifting out of a sense of ethics, and third is that
all intelligent alien civilizations are destined, no matter what, to go extinct because through
the development of intelligence there are simply too many ways to snuff out, and it
gets worse the more technological you become.
Indeed, it’s been advanced in astrobiology that artificially created climate change necessarily
must be common to all alien civilizations as they develop.
At the same time however, technology can also be a saving grace.
If you develop a global climate problem and can’t curtail whatever it is you’re doing
to cause it, then you reach technological solutions to the problem.
You could for example change the albedo of your planet to reflect more sunlight if you’re
experiencing warming, this merely involves artificially creating slightly more cloud
cover over the surface of your planet.
Another could be the release of reflective aerosols into your atmosphere, or even the
construction of a sun shade in orbit of your star, that blocks out a percentage of light
hitting your planet.
This really would represent a kind of reverse terraforming where you’re re-terraforming
your planet back to what it was before the problem developed due to your technology causing
the problem in the first place.
In the end, intelligence may be a double edged sword in the great scheme of things.
The development of it could result in extinction, and the technological result of it could lead
to extinction and does so for most alien civilizations and that our quest for a solution to the Fermi
Paradox may have an irony to it, that which could formulate the paradox in the first place,
ultimately ends up being its solution.
Thanks for listening!
I am futurist and science fiction author John Michael Godier currently unsettled by the
realization that we’re ultimately here because we like to eat lots of stuff.
That would mean that The picky eater alien does not get the brain, I think it’s time
for a hot dog 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.