present positions and with climates unlike those of today. That is when the major angiosperm radiation took place. Thus, butterfly evolution must be studied throughout the elaboration and testing of phylogenetic hypotheses and through historical zoogeography. Researchers who accept a Cretaceous origin for the butterflies generally favor vicariant zoogeographic hypothesis for how the major lineages of butterflies came to be distributed over the world, whereas those who favor a Tertiary age rely on dispersalist hypotheses (Lamas, 2008). Drivers of speciation Mimicry, hybridization, and co-evolution with host plants have probably contributed to speciation in the butterflies (Lamas, 2008). References Ehrlich, P. R. (1958). The comparative morphology, phylogeny and higher classification of the butterflies (Lepidoptera: Papilionidea). Kansas Univ. Sci. Bull., 39, 305-370. Grimaldi, D. & Engel, M. S. 2005. Evolution of the insects. Cambridge: Cambridge Univ. Press. Lamas, G. (2008) Systematics of butterflies (Lepidoptera: Hesperioidea and Papilionoidea) in the world: current state and future perspectives (in Spanish). In: Jorge Llorente-Bousquets and Analía Lanteri (eds.) Contribuciones taxonómicas en ordens de insectos hiperdiversos. Mexico City: UNAM. pp. 57–70. Scoble, M. J. (1995). The Lepidoptera, form, function and diversity. London: The Natural history Museum & Oxford University Press. Col, Jeananda. (1999) Enchanted Learning - All About Butterflies http://www.enchantedlearning.com/subjects/butterfly/allabout/ Butterflies Butterflies