forgedsignatures t1_jbimz2l wrote

Ecology and conservation student - In reality we know fuck all about a lot of interspecies relationships. Sometimes a byproduct or the knock on effects of a species existing in an area is the reason the rest of the animals in that area are flourishing (and are called keystone species), if that animal is removed the ecosystem falls apart and is forced to find some new functional equilibrium.

(This bit is off memory and it was a while ago we covered this unit - specifics like species may be off but the sentiments are right) A scientist called Bob Paine discovered keystone species in I want to say the 80s by walking down to a particular rock on a beach and tossing all the starfish into the water and monitoring the other species. As time went on, without the starfish the species they predated upon became populous and overbred and overconsumed the species below them leading to the local extinction (on that rock) of both themselves and their prey animal pretty much leaving only animals like barnacles (which subsist off of food particles in the water), their predators, and photosynising organisms were left on the rock.

In short the starfish correctly managed the species beneath them and stopped them becoming an issue without overpopulating themselves; in their absence the next highest predator took advantage and overindulged leading to the exctinction of 3 species on that rock rather than the seemingly insignificant 1. The keystone species isn't always the highest predator though, it can be one further down the food chain.

Video on the starfish rock that I am unable to watch where I currently am.