Source
r/evolution•
ConnorI

Help with identifying a term or concept within evolution

academic

A few years ago I watched a nature documentary, I believe it might’ve been from BBC. The part that stuck out to me was when the narrator said something along the lines of “when there is lots of competition/all the roles have been filled in the food chain. There is a little Evolution, taking place. When there is a little competition and plenty of open spaces in the food chain, then you will see a lot of evolution.”

Has anyone heard a saying similar to this, or know the term/concept this is called?

Posted Sep 22, 2023, 10:54 PM UTC

18
pali1d•

Sounds like punctuated equilibrium to me.

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ConnorIOP•

Thanks! After reading the overview it does seem to match.

1
BMHun275Microbiology•

The concept you're referring to is often related to ecological niches and evolutionary rates. In biology, it's sometimes described as "adaptive radiation." This occurs when a group of organisms diversifies rapidly into different species, especially when they occupy various ecological niches with less competition and available resources.

The idea is that when there are fewer competitors or available niches, species may evolve to exploit those niches more rapidly, resulting in greater diversification and evolution. Conversely, when all ecological niches are already occupied or there is intense competition, evolution may occur at a slower pace since there is less room for new adaptations to emerge.

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ConnorIOP•

Awesome thanks for the help!

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ErichPrydeEvolutionary Biology•

I would say that an ecosystem where all the roles are filled is probably a climax community, where ecological succession has temporarily stopped.

Massive evolutionary radiations occur as a result of ecological disaster, mass extinction, or anything else that results in population bottlenecks or extinction of some populations. Or, a group of organisms expanding into a new and relatively organism free environment.

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ConnorIOP•

Thanks for the explanation on what could cause this type of process to occur!

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Rubenson1959•

The 2nd half of the quote sounds like adaptive radiation in the presence of open/empty niches. The first half sounds like the consequence of niche specialization to reduce resource competition between species. The saying doesn’t sound familiar. It also sounds right using food chains as a simplification of food webs in ecosystems.

Here’s the example I was thinking of.

https://www.biointeractive.org/classroom-resources/origin-species-lizards-evolutionary-tree

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ConnorIOP•

Thanks very much for the example/video!

1