#57. Where are All the Space Aliens? [evolution]

EV

Red, theory; black, fact.

KIRK MUST DIE! (cut to commercial.)

Astronomical observations and the Fermi paradox

Contemporary exoplanet research keeps turning up extra-solar-system planets that seem to be promising abodes of life of the Earthly variety (never mind the completely weird biochemistries that may exist on other planets). In the habitable exoplanets catalogue (HEC), kept by the Planetary Habitability Laboratory (University of Puerto Rico) at Arecibo, the list of planets found orbiting in the conservative habitable zone now has 17 entries, and a 2013 paper by Petigura et al. ("Prevalence of Earth-size planets orbiting Sun-like stars") placed the percentage of stars in our galaxy with potentially habitable planets at 22 ± 8. Accumulating evidence suggests that life is common in our galaxy, yet SETI research—the search for extraterrestrial civilizations that send out radio signals that bear some stamp of intelligence—has drawn a complete blank, as far as I know. (And if it did find something, it would make such a sensation in the media that no-one could help knowing.) So I ask you: where are all the space aliens? (This question is generally attributed to 20th-century physicsmeister Enrico Fermi and has since become known as the Fermi Paradox.)

My hypothesis is this:

Life is one thing; intelligent life is quite another. This is a form of the Rare Earth hypothesis, which is one of the avenues that has been explored through the years in the search for a resolution of the Fermi Paradox.

Biospheres may not be permanent 

No doubt there are many, many planets in our part of the galaxy that have some form of primitive life, and many, many more "graveyard planets" that once had life but are now sterile. Mars may well be an example of this kind of planet in our own solar system.

Biochallenge!

I conjecture that if we seem to be alone in this part of the galaxy, based on the negative SETI evidence, it is because we are, and this is because we have evolved to the level of intelligence first in this galactic neighborhood, because evolution on the Earth is egregiously rapid. It has taken us four billion years to get this far, which doesn't sound so fast, but everything is relative. This rapid evolution is plausibly a response to challenges: all the various natural disasters we are subject to here on Earth, examples being bolide (meteor) crashes, continental glaciations, drifting continents, droughts, earthquakes, floods, hurricanes, long climatic warm spells, tornadoes, tsunamis, volcanism, wild weather, wildfires, and winter.

Sept 23, 2018: Tornadoes knock out primary transformer station in Ottawa.

Case in point: a large bolide strike is believed to have triggered the extinction of the dinosaurs, making way for the rise of the mammals, and we ourselves are the descendants of those mammals. <03-21-2020: The bolide may have killed the dinosaurs indirectly, by touching off a climate shift in our dangerously unstable world. This would explain the temporary presence of dinosaur fossils above the Cretaceous/Tertiary iridium anomaly, which has been a problem for the bolide hypothesis.>

Case in point: the rise of modern humans seems to have coincided with the end of the last continental glaciation. The rigorous, cold-climate conditions prevailing then might have selected our ancestors for high ability in building shelters and sewing protective clothing. These skills might have required the rapid evolution of a high ability to process spatial information, which we then leveraged into the building of civilizations upon the return of temperate climatic conditions. (See: #24, "The Pictures in Your Head," this blog.)

To contrive a planet that is so challenging and difficult, yet has not succeeded in destroying life altogether in four billion years, may require a very rare combination of parameters (e.g., our distance from the sun, the size and composition of the Earth, the presence of the asteroid belt, the presence of the Oort cloud), and this rarity has led to our emerging into intelligence before it happened anywhere else in this part of the galaxy.

01-08-2020: These parameters may well have special values at which critical behavior occurs, such as the onset of positive feedbacks leading to heating or cooling. Earth may be simultaneously close to several of these critical points, a rare circumstance, but one that does not require extreme, atypical values of any given variable.

My take on the Rare Earth hypothesis therefore emphasizes what are called "evolutionary pumps" (e.g., glaciations, bolide crashes, etc.) in discussions of this hypothesis, as well as the anthropic principle.

August 28, 2011: An Ottawa sunset inflamed by a recent hurricane in the USA.

Evil-ution

I further conjecture that the difficulties of our past have left their mark on us, and we call it "evil." (Some will deny that this concept has any construct validity, saying, "It's not a thing," but I think that it is an approximate version of something that does, which I term "dispersalism" in this blog.) This is because a basic strategy for surviving disasters is dispersal, which I have previously linked to evil in these pages (See: #35, "The Pilgrim and the Whale," and #37, "Two Kinds of War," this blog).

To recapitulate, our planet's predilection for disaster has deeply ingrained dispersal tendencies into most species here, by the mechanism of natural selection. Humans now get their food from agriculture. However, agriculture requires a settled existence and is therefore in opposition to dispersal, so the plot thickens.

This characteristic of agriculture results in the psychological pressure for dispersal relentlessly building, pressure-cooker fashion, across time, until a destructive explosion occurs (war or revolution), thereby accomplishing the long-delayed dispersal.

May 21, 2022 derecho-storm damage in Ottawa.

Wildfire smoke seen in Ottawa, Jun 2023.