in reality, the population seems more likely to go extinct because of poor environmental conditions, random environmental fluctuations, loss of cultural knowledge (which, like genetic variation, goes down in small populations), or lack of physical goods and technology, none of which have much to do with genetic variation.
This matches what I had tentatively believed before seeing your commentâi.e., I had suspected that genetic diversity wasnât among the very most important considerations when modelling odds of recovery from collapse. So Iâve now updated to more confidence in that view.
I raised MVP (from a genetic perspective) just as one of many considerations, and primarily because Iâd seen it mentioned in The Precipice. (Well, Ord doesnât make it 100% clear that heâs just talking about MVP from a genetic perspective, but the surrounding text suggests he is. Hanson also devotes two paragraphs to the topic, again alongside other considerations.)
Perhaps we should keep the term âminimum viable population sizeâ but use a broader definition based on likelihood to survive, period. I see that Wikipedia uses a broad definition that includes extinction due to demographic and environmental stochasticity, but often MVP is used as in the OP to refer just to extinction due to genetic reasons, so it is important to clarify terms.
Iâd agree that clarifying what one means is important. This is why I explicitly noted that here I was using MVP in a sense focused only on genetic diversity. To touch on the other âaspectsâ of MVP, I also have âWhat population size is required for economic specialisation, technological development, etc.?â
It seems fine to me for people to also use MVP in a sense referring to all-things-considered ability to survive, or in a sense focused only on e.g. economic specialisation, as long as they make it clear that thatâs what theyâre doing. Indeed, I do the latter myself here: I write there that a seemingly important parameter for modelling odds of recovery is âMinimum viable population for sufficient specialisation to maintain industrialised societies, scientific progress, etc.â
Another way in which the concept of a MVP is too simplistic...
I wasnât aware of these points; thanks for sharing them :)
Thanks for your response and the link to your newer post and the Ord and Hanson refs. Iâll just add a thought I had while reading
This is why I explicitly noted that here I was using MVP in a sense focused only on genetic diversity. To touch on the other âaspectsâ of MVP, I also have âWhat population size is required for economic specialisation, technological development, etc.?â
It seems fine to me for people to also use MVP in a sense referring to all-things-considered ability to survive, or in a sense focused only on e.g. economic specialisation...
This all makes sense, but sounds to me like to be at risk of leaving out the population/âconservation biology perspective (beyond genetic considerations). A large part of what motivated me to write my original post is that I do think it is indeed valuable to use frameworks from population and conservation biology to study human extinction risk - but it is important to include all factors identified in those fields as being important; namely, environmental and demographic stochasticity, as well as habitat fragmentation and degradation, which could pose much greater risks than inbreeding and genetic drift.
Yeah, that sounds right. Those factors were left out just because I didnât think of including them (because I donât know very much about these frameworks from population and conservation biology), rather than because I explicitly decided to include them, and Iâd guess youâre right that attending to those factors and using those frameworks would be useful. So thanks for highlighting this :)
There are probably also various other âcrucial questionsâ people could highlight, as well as questions that would fit under these questions and get more into the fine-grained details, and Iâd encourage people to comment here, comment in the google doc, or create their own documents to highlight those things. (I say this partly because this post has a very broad scope, so a vast array of fields will have relevant knowledge, and I of course have very limited knowledge of most of those fields.)
Very interesting, thanks! Strong upvoted.
This matches what I had tentatively believed before seeing your commentâi.e., I had suspected that genetic diversity wasnât among the very most important considerations when modelling odds of recovery from collapse. So Iâve now updated to more confidence in that view.
I raised MVP (from a genetic perspective) just as one of many considerations, and primarily because Iâd seen it mentioned in The Precipice. (Well, Ord doesnât make it 100% clear that heâs just talking about MVP from a genetic perspective, but the surrounding text suggests he is. Hanson also devotes two paragraphs to the topic, again alongside other considerations.)
Iâd agree that clarifying what one means is important. This is why I explicitly noted that here I was using MVP in a sense focused only on genetic diversity. To touch on the other âaspectsâ of MVP, I also have âWhat population size is required for economic specialisation, technological development, etc.?â
It seems fine to me for people to also use MVP in a sense referring to all-things-considered ability to survive, or in a sense focused only on e.g. economic specialisation, as long as they make it clear that thatâs what theyâre doing. Indeed, I do the latter myself here: I write there that a seemingly important parameter for modelling odds of recovery is âMinimum viable population for sufficient specialisation to maintain industrialised societies, scientific progress, etc.â
I wasnât aware of these points; thanks for sharing them :)
Thanks for your response and the link to your newer post and the Ord and Hanson refs. Iâll just add a thought I had while reading
This all makes sense, but sounds to me like to be at risk of leaving out the population/âconservation biology perspective (beyond genetic considerations). A large part of what motivated me to write my original post is that I do think it is indeed valuable to use frameworks from population and conservation biology to study human extinction risk - but it is important to include all factors identified in those fields as being important; namely, environmental and demographic stochasticity, as well as habitat fragmentation and degradation, which could pose much greater risks than inbreeding and genetic drift.
Yeah, that sounds right. Those factors were left out just because I didnât think of including them (because I donât know very much about these frameworks from population and conservation biology), rather than because I explicitly decided to include them, and Iâd guess youâre right that attending to those factors and using those frameworks would be useful. So thanks for highlighting this :)
There are probably also various other âcrucial questionsâ people could highlight, as well as questions that would fit under these questions and get more into the fine-grained details, and Iâd encourage people to comment here, comment in the google doc, or create their own documents to highlight those things. (I say this partly because this post has a very broad scope, so a vast array of fields will have relevant knowledge, and I of course have very limited knowledge of most of those fields.)