Do Groups exist?

Making a stub here to complete a general question: are groups real.

(1) broadly the question is: can everything be reduced to components.

(1.1) developments in recursive maths, computing and fractals suggest that you can understand the collective as emergent properties of simpler/smaller components. In fractals the recursive components are copies of the collective, and vice versa. However you can argue that if you know the component you know the whole. The question here is there every anything in the collective that cannot be explained by the parts.

(2) An old question from university. Do Communities exist? The question here is can everything in an environment be reduced to the behaviours of component organism, so that there is no need to imagine a new collective entity.

(3) Buddha says that all collections are illusion because they can be replaced by the parts.

(4) Group selection suggests that there is a direction of evolution that can only be explained by a collective entity and not by the parts. Even today this remains undecided.

(5) In AI the limit for a transformer suggests there is some entity that is at least a simplification of the parts. However by definition the abstraction depends upon the training set so cannot be separated from it. In philosophy this is similar to the statement that all knowledge begins with experience. While we may abstract entities, they ultimately stand upon evidence. 

===

Okay these are big chats with ChatGPT so references here:

Are there any examples of phenomena that can only be explained by reference to a collective entity and not the parts? [this evolves into a debate on genes]
https://riswey.blogspot.com/2025/04/death-of-dawkins-dennett-and-other.html