Temporal evolution of the predicted oxygen abundance gradients associated with four simulated L^∗ disc galaxies – from the MUGS (Stinson et al. 2010) and MaGICC (Brook et al. 2012b) suites – in addition to an analytical model (SB09: Schönrich & Binney 2009). Symbols correspond to empirical determinations of the abundance gradients in a sample of high-redshift lensed systems (Yuan et al. 2011; Jones et al. 2013), intermediate-redshift galaxies from MASSIV (Queyrel et al. 2012), local discs (Rupke et al. 2010), and the Milky Way (Maciel et al. 2003; Stanghellini & Haywood 2010).