Toxin profile and geographic variability of B. jararaca venom were investigated.
SE and S B. jararaca populations exhibit distinct venom proteomes and bioactivities.
Post-transcriptional and ontogenetic regulation underlies geographic venom variation.
Population markers suggest that B. insularis stem in the SE B. jararaca phylogroup.
Bothropic antivenoms exhibit paraspecificity against SE and S B. jararaca venoms.