We have a new paper out in Nature Communications on testing hypotheses for latitudinal gradients in ants. This is the first paper to really present and analyze the full scope of the GABI database of all ant species distributions. To complement the species range data, we did a very extensive phylogenetic and dating analysis, including implementing the fossilized birth-death process with 500 fossil taxa informing the dating. We analyzed the geographic and phylogenetic data together to test hypotheses for the latitudinal gradient, including variation in diversification rate and time. We generally found the latter to be most consistent with explaining the gradient.
We also did a complementary study focusing on Pheidole, which deals with emergence of the gradient on more recent timescales. A preprint of that one is available on bioarxiv.