22 December 2007

Planning for Apocalypse: Minimum Viable Population

Basic survival planning for natural disasters is very important. But such disasters are relatively short-lived, with normal services being restored within a week or two at the most, typically. An existential risk--or extinction hazard--is different. When making contingency plans for an existential risk situation, it is important to take as many significant complications of large scale human extinction as possible. First, you must assure immediate survival of the extinction event, plentiful long-term food and water for a minimum of months, defense against ongoing human and environmental hazards, safe disposal and recycling of waste, etc. Consider those first-tier contingencies. Among second tier contingencies to be considered in planning, is minimum viable population (MVP).

MVP is the minimum number of healthy surviving individuals that would maximise long term survival of the population without excessive loss of genetic variability through genetic drift--without losing evolutionary potential. The safest estimate of MVP is approximately 10,000 individuals--roughly the number of humans supposed to survive the Toba catastrophe 75,000 years ago.

While no one can know what human genetic potential may have been lost during that existential bottleneck of human evolution, it is important to recognise that any human survivors of an existential hazard must deal with the founder effect.
When you are planning your large-scale survival bunker, your generation ship, your large underwater habitat, your seastead, your orbiting colony, or your moon colony--how many people should you plan to accommodate, to be sure humanity can perpetuate itself?

If all of the Lifeboat Foundation's preventive efforts to ward off existential risk fail, how many people need to make it through? While 10,000 may be enough, what if your project cannot save 10,000? In this simulation, a population of 500 was enough to prevent more than 1% genetic loss over 100 generations. If your project was allied with several other projects dispersed across a large geographical area, the survival of at least one or more groups would be more likely. In that situation, multiple groups of 50 to 100 individuals might be viable in the long term, should at least a few groups survive. Geographic dispersal into small groups should guarantee a greater genetic variety--making the entire set of survivors more genetically viable for a larger number of generations.Ideally, each survival location should contain a nucleus of trained individuals with sufficient knowledge to form a small university. In contrast to most modern universities and secondary schools, the post-survival university would emphasize practical knowledge and skills. Medical, surgical, agricultural, construction, machine fabrication and maintenance skills, air and water purification skills, and skills for defense against animals (including human), microbes, and natural disasters would be paramount. It is clear that in a practical survival situation, 90+ per cent of modern university professors would be worse than useless.

Location of your project should take into account the likely hazards as well as resources remaining in that location, after the extinction risk passes. Is there a natural barrier between your location and the most likely post-existential risk hazards? Will your water supply be clean or polluted by fallout, biohazard, etc? You will have to custom design your recovery supplies and equipment for what you are most likely to face on emergence.

If you are planning a modular project design, perfecting your modules will be a top priority. With such a perfected design, you have a greater ability to expand your project to meet your eventual personnel needs. If you are planning a single large or medium-sized project, you will need to begin immediately to size, and further specify the qualifications of your prospective list of projectees.

Technology for autonomous land vehicles, ships, and planes is developing rapidly. A forward planning apocalyptologist would provide for UAV scouting capability--perhaps using land and aerial UAVs to check if "the coast is clear" before committing to leave the relative safety of the project.

Farther in the future, iff you find yourself in the position of planning a generation ship, you might consider styling it after the O'Neill space colony:
The most common vision for generation ship design is to model it after an O'Neill colony, first proposed by Gerard O'Neill in the 1970s. This is basically a gigantic rotating cylinder or disk with an interstellar propulsion system attached. The cylinder may be from several hundred meters to several hundred kilometers in diameter, and rotated on its long axis to provide artificial gravity along its inner curved surface. The interior is sculpted and pressurized to provide an Earth-like environment, complete with forests, hills, streams, lakes, and so on. The inner environment is usually envisioned as being large enough to generate its own weather, supplemented and/or controlled by the ship's systems. On an orbiting O'Neill colony, light would be provided by gimbaled mirrors and enormous transparent sections of the hull. On an interstellar generation ship, illumination would have to be provided by large strips or nodes of lighting equipment recessed into the inner surface.

An O'Neill style generation ship could ultimately hold from 10,000 to several hundred thousand inhabitants, depending on its exact size and design. Source

With such a ship, you could easily accomodate an MVP. Otherwise, you might want to consider an embryo ship, with a large number (10,000+) of genetically healthy and diverse embryos. An alternative approach, to save resources, is the hibernations ship--where all but a skeleton crew are kept in suspended animation.

The number of issues that must be considered when facing an apocalypse is quite large. Some existential risks are simply not survivable, no matter your resources or planning. We are not concerned about those. We continue to develop our plans for the coming Society for Creative Apocalyptology (SCA), but we will be taking note of important issues in the meantime here at Al Fin.

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Blogger IConrad said...

Tiny point of order:

> without losing evolutionary potential.

Bottleneck events are tied to evolutionary migration. It is, in fact, the smaller populations in which evolutionary changes occur. The larger the interbreeding population, the less likely evolutionary change -- due to the regression to the mean.

Saturday, 22 December, 2007  
Blogger al fin said...

Yes, Darwin discovered speciation occurring in isolated breeding populations--as on islands, and wherever local breeding populations are isolated.

But if genetic variants are lost in the process of population isolation and subsequent genetic drift, it is as if evolution's hand is being forced--it must make the most of the hand it has been dealt.

I am not certain that evolution is not occurring within larger breeding populations, however. Observing the process may require more perspective, or better tools of observation.

Small population evolution may achieve local optima, whereas evolution in larger populations may approach more global optima. Interesting question.

Certainly a larger population with more genetic variants should be able to respond to a wider variety of environmental "forcings" or evolutionary prompts.

Sunday, 23 December, 2007  
Blogger IConrad said...

You have to remember that no species exists in a genetic vacuum. The characteristic of large populations of species of reversion to the mean guarantees that any unique genetic/evolutionary events will normalize out within a few generations.

It is only in isolated populations that the process of genetic drift can take hold and provide for radical alterations.

For example; remember that at any given time we humans share roughly 5% of our genome with bacteria.

Given that this is greater than the genetic variance between humans and our next-closest species group (genus), then it becomes clear that evolution works in ways we haven't even begun to comprehend. :)

Sunday, 23 December, 2007  
Blogger al fin said...

You have to remember that no species exists in a genetic vacuum.
Quite true. That is where the term "coevolution" comes from. Natural selection includes environmental forcings, but those are only a part of the story. Genes get injected into the DNA by viruses, and the existing genome experiences mutations, while modifications in the epigenetic mechanisms occur while we are looking in another direction.

Now that humans are learning how to inject genes into the nucleus, and where in the genome to put them, things may become more interesting. All the different ways of blocking gene expression may prove just as important as the ways to promote gene expression.

What is your best guess for the MVP?

Monday, 24 December, 2007  
Blogger IConrad said...

> What is your best guess for
> the MVP?

I honestly don't know, but I'd have to say that we have to start thinking in terms of survival of civilization rather than of the species.

That number might be higher, and it might be lower. But I //do// know that it is currently increasing. I would guess that 10,000 is a good number pre-assuming that we weight the survivors for their technological & scientific expertise, weighted to about half 'experts' and half 'do-ers'; soldiers & technicians would be my best guess on that one.

I'm purely pulling all that out of my ass, though; I don't know and haven't researched. It's all guess-work.

Thursday, 27 December, 2007  
Blogger al fin said...

Good point. While I would expect experts to have some doer skills, and doers to have some quasi-expert skills, I would add a third category to the "experts" and "doers": The third category would be "informed dreamers."

While most university professors seem to be uninformed dreamers, the "informed dreamers" I have in mind would also have some expert and doer skills--but they would be expected to spend most of their time creating new ideas, techniques, pasttimes, etc.

Natural instinctive creators are probably born that way, although I would expect most of the "founders" to be trained in lateral thinking and basic creativity.

A different minimum IQ for doers, experts, and dreamers respectively might apply. It is vital to consider prefrontal executive function just as important as IQ, creative skills, expert knowledge, and other talents.

Lastly, emotional balance and vitality are important. Resilient personalities, who can find reasons to live long and prosper after losing most of what they had known, are indispensable.

Friday, 28 December, 2007  
Blogger weedleambrose said...

You have lost something already. I increased my IQ from 118 in High School to 126 in college. I have not recently taken the tests but I would venture to say it has increased again. This puts your assumptions into question because you have left out the driven induvidual and the adept at stress situations you get from the more criminal element. The hard pressed often develope remarkable survival instincts and skills for simple survival decisions that always pan out better in the long run.

Tuesday, 26 January, 2010  
Blogger weedleambrose said...

You need to rework the hypothesis to include fring elements that normal rules of society would leave out for moral reasons.

Tuesday, 26 January, 2010  

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