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Small-Scale Question Sunday for January 22, 2023

Do you have a dumb question that you're kind of embarrassed to ask in the main thread? Is there something you're just not sure about?

This is your opportunity to ask questions. No question too simple or too silly.

Culture war topics are accepted, and proposals for a better intro post are appreciated.

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A while back on 4chan, I saw an interesting quote from a book that said something along the lines of:

The larger a system is, the less diversity it can support. Something something, the galapagos islands have vastly more biodiversity than north America despite being much smaller

Now, I didn't save the picture, and it was photograph of a page of a book. I tried searching for "larger" "system" "less diversity" "support", but you know how terrible google is about finding anything that isn't an "approved" mainstream news article nowdays. I ended up finding a paper called Why do several small patches hold more species than few large patches? that was tangentially related, but it seems to be more focused on conservation. Any idea what I could search for to find more information about this as a general topic? I feel like this could "The larger a system is, the less diversity it can support" is a very interesting premise that could describe a lot of topics, especially sociological and economic topics.

The larger a system is, the less diversity it can support. Something something, the galapagos islands have vastly more biodiversity than north America despite being much smaller

As has been mentioned below, it depends what you mean by "more biodiversity". I seriously doubt this is true in an absolute sense - North America covers a much larger range of biomes than the Galapagos and therefore likely has a higher total number of species. On the other hand, the Galapagos might win out if you're measuring biodiversity by species per square inch, but that's to be expected given that the Galapagos is situated in a warm equatorial environment whereas North America is a much larger landmass that includes extremely cold northerly environments and contains biomes like taiga where biodiversity is generally low, so that drags down the average.

I ended up finding a paper called Why do several small patches hold more species than few large patches? that was tangentially related, but it seems to be more focused on conservation.

It makes sense that this would be the case. The geographical isolation of populations from each other allows for allopatric speciation, where two populations of the same species diverge because they get to develop in isolation without gene flow between the groups (example: the Abert and Kaibab squirrels). Populations being dispersed into several small patches of habitat as opposed to a few larger ones clearly helps enable this process.