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:…importance of polyploidy because (1) life history traits are often main determinants of fitness (e.g., Levy and Feldman 2002; Otto 2007; Ramsey 2011), and (2), ploidy level has the potential to influence life history traits in both positive and negative ways (e.g., Cavalier-Smith 1978;…
Category: