Evoluce zmijovitých hadů a role klíčových inovací v jejich diverzifikaci

Waldhauser, Vojtěch

The family Viperidae consists of 36 genera, containing more than 350 species in total. The family is distributed throughout Africa and most of Eurasia, however the greatest diversity is located in North and South America, where more than 40 % of the viper species can be found. The family is thus missing only in Australia, New Guinea, Madagascar, New Zealand and a number of other islands and archipelagos. As with most reptiles, they are also almost completely absent from polar regions, with the exception of Vipera berus, the only snake that has ventured north of the Arctic Circle. Their relative evolutionary success is attributed to many so called "key innovations", which include solenoglyphous dentition, viviparity of many genera or heat- sensing pits in the subfamily Crotalinae. Vipers are not only interesting because of their evolutionary history, but they are also subject of important medical studies regarding their venom and toxicity. WHO estimates that around 100,000 people worldwide may die from snake bites each year. This thesis presents a summary of our current knowledge of the evolutionary history of this family, including phylogeny and biogeography, and contemplates the mechanisms behind its amazing diversity.

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