Evaluate the collective function of references cited together in a given text segment.
Classify their combined role into one of the following categories: 'method', 'background', or 'result'.

Text:Andean uplift was one of the major drivers of biodiversity organization in South America (Gentry 1982; Jørgensen & Le on-Y anez 1999; Antonelli et al. 2010; Hoorn et al. 2010).
Category: