Full Idea
A commitment to wholes is a commitment to entities that are numerically distinct from their parts (by Leibniz's Law, they don't share all of their properties - the parts typically exist, but the whole doesn't, prior to its creation).
Gist of Idea
Wholes are entities distinct from their parts, and have different properties
Source
Kathrin Koslicki (The Structure of Objects [2008], 3.1)
Book Reference
Koslicki,Kathrin: 'The Structure of Objects' [OUP 2008], p.45
A Reaction
Presumably in classical mereology no act of 'creation' is needed, since all the parts in the universe already form all the possible wholes into which they might combine, however bizarrely.