35Monitor lizards are unique among ectothermic reptiles in that they have a high aerobic capacity 36 and distinctive cardiovascular physiology which resembles that of endothermic mammals. We 37 have sequenced the genome of the Komodo dragon (Varanus komodoensis), the largest extant 38 monitor lizard, and present a high resolution de novo chromosome-assigned genome assembly 39 for V. komodoensis, generated with a hybrid approach of long-range sequencing and single 40 molecule physical mapping. Comparing the genome of V. komodoensis with those of related 41 species showed evidence of positive selection in pathways related to muscle energy 42 metabolism, cardiovascular homeostasis, and thrombosis. We also found species-specific 43 expansions of a chemoreceptor gene family related to pheromone and kairomone sensing in V. 44 komodoensis and several other lizard lineages. Together, these evolutionary signatures of 45 adaptation reveal genetic underpinnings of the unique Komodo sensory, cardiovascular, and 46