Why Inbreeding and Percolation Explain the Fermi Paradox
The Fermi Paradox, Percolation, and Inbreeding
I recently connected Geoffrey Landis' percolation theory to Lindsay Nikole's work on cheetah genetics to solve the Fermi Paradox. Interstellar colonization creates severe genetic bottlenecks, much like the catastrophes that nearly wiped out cheetahs. As colonies branch out, genetic diversity plummets, leaving new populations vulnerable to extinction. This biological fragility likely causes expansion to terminate long before filling the galaxy.
Extend the sequence far enough and you probably get populations that are functionally so closely related you could do skin grafts between random individuals.
- margalabargala
This argument doesn't resonate with me.
Looking at the chart of "Each colony hop has 90% the "diversity" of its parent", we see that by the 10th we only have 34% diversity left.
It's not at all clear that 34% of diversity is too small. On earth right now, we had smaller groups of people arrive at some general location and tend to mostly reproduce within that group, creating what we now call "ethnic groups". Is 34% diversity more or less diversity than currently exists in, say, Ireland, or Norway?
Furthermore, the article completely ignores that over time spontaneous mutations contribute new genetic diversity. It doesn't give a time scale for the "send a ship, wait for the colony to grow large enough to colonize a new world" iteration but I would imagine that in the time it takes that to happen 10 times sequentially you will have more than enough new genetic diversity.
- Nevermark
> Furthermore, light-speed lag and distance mean that child civilizations must be functionally independent of parent cultures.
Makes me wonder if a solar system wide civilization, with trillions of beings, wouldn't invest in ships to go to the next system, extract resources, and create a stream of resources ships going back to the original solar system.
That might sound uneconomical. Why not just go to the other system? But moving trillions of beings, and disrupting all their practical considerations and dependencies, would be a far more costly enterprise.
In the short run it would be resource acquisition. In the long run, the new system would accumulate entities, and then a civilization of its own. But there might still be strong value, or incentives, for the original system to continue acting as a kind of capital/dominant/higher value location.
Long distance/time dependencies could develop and be naturally maintained via complex decentralized indirect but intertwined economic arrangements. Just as shareholders who have done nothing but push a button on their phone to get an electronic record of having some stock in a company, have strong property rights over complex systems they may never see or understand, because it is in everyone's interest for the system to keep working.
Also, automated systems that defend themselves and their owners positions, even across a few light years. With the owners being able to trade their value in real time, even if the physical returns are l […]
- randomImmigrant
Are we conveniently assuming that only humans will be able to read and tweak their genomes, and do synthetic biology?
An odd assumption if we’re generously granting FTL or even regular space travel to aliens.
Everything from the lack of radio communication to the commonness of biological precursors like nucleic acids and amino acids in space points to multicellularity being the relatively rare thing, at least in our part of the galaxy.
We don’t hear from them or see them because if they’re out there, they’re still microbes eating each other. That one case of the two forming a symbiotic relationship, which leads to more endosymbiosis… that’s where I suspect our real rareness lies.
- jmyeet
This is a kinda silly argument. Interstellar colonies would have the opposite problem: they'd cease to be the same species due to genetic drift.
If you look at the (im)practicalities of interstellar travel, it's going to take centuries. That means a generational ship of some kind. That means having a sufficient population to get there, which really means tens of thousands of people. Plus, the kind of ship that would make that would likely host up to millions. That's just not going to create a genetic bottleneck.
Also, you could even mitigate that by bringing frozen genetic material.
- gmuslera
Didn't followed the reasoning. What is "one colony"? some genetically homogeneous expedition? Unless you get a more or less continuous flow of colonizers from the home world, to be viable it needs hundreds of diverse individuals to kickstart. And setting, viability, being self-sufficient, becoming widespread enough within the planet to survive climate/tectonic/etc events should be in the picture unless it is an elaborate and very expensive way to get rid of some troublesome individuals. Establishing one colony nearby in Mars is still far from being feasible with today's knowledge and technology, and probably not so close technology too.
Even generational ships are a challenge, but more important, if we are able to make long term self-sustaining generational ships maybe we won't need to land, or change the equation between traveling and settling.
In any case, we didn't reach any outer solar system planet yet, not even with probes. We might not be fully aware of many of the practical problems of reaching and settling on another solar system planet. We might be like ancient mesopothamians asking ourselves why we shouldn't be able to build a tower to the moon.