site banner

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.

6
Jump in the discussion.

No email address required.

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.

I think a large area allows for generalist - specialist creatures. That's not a great term, but animals that evolve that can counter common survival strategies.

It's probably more clear if I give some examples.

Giant bugs are common on islands. At least until humans accidentally introduce rats. Then suddenly all the giants bugs are gone.

House cats are amazing at wiping out unique bird species.

Australia is famous for its large number of venomous species. It also doesn't have any mustelidae. Honey badgers would be very successsful.

Australia is famous for its large number of venomous species. It also doesn't have any mustelidae. Honey badgers would be very successsful.

I really don't think honey badgers will be able to evolve resistance to the entire palette of Australians venomous critters, much less come pre-equipped.

House cats are amazing at wiping out unique bird species.

House cats are really good at destroying wildlife overall. very efficient killers

Feral house cats, the ones who were born on the streets and raised by nature, are terrific at killing. Those raised in houses by humans are quite inefficient. especially those who know they have a home to return to, and food to eat.

Take care to spay or neuter your captive fluffy descendants of the beasts who hunted your ancestors. Those who can spawn will inevitably screw.

I suspect the disparity between island bird species vs continental bird species capacity to protect are much greater than between-cats attack capacity disparity.

If you know the thread title, or any sequence of words in the thread, you can search on the 4plebs archive website to try to find it.

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.

the galapagos islands have vastly more biodiversity than north America

Is that actually true? And in which terms "more biodiversity" - more species in general, starting from Archaea and viruses up to primates? More species per square inch? Did somebody really conduct such a research? How did they count the species and what was the result?

This is a wild guess. But my intuition is that:

Let's model a system as follows.

  • There exists a space where multiple agents have to compete for some finite and some infinite resources.

  • Some of these agents spawn stochastically.

  • Agents can grow and die. (Assume some randomness here too)

  • Agents can destroy other agents and absorb them.

  • Agents have some kind of gravitational field, where a larger size is a competitive advantage.

  • The above feature ensures power law distributed size.

Leading to; In a large system, given enough time; Certain agents can gather such 'mass' that they just immediately kill or absorb any new agents that pop up. And they are disproportionately harder to fight against as time goes on.

Think monopolies, think mainstream culture, think religions. The system I intuited above can describe memetic systems at a certain level of abstraction.