Leibniz Institute for the Analysis of Biodiversity Change
Bonn, Germany

Abstract

The talk will try to draft a picture of some major events in insect evolution by combining the final phylogenomic analyses of the international 1KITE project and morphological data with a focus on the tracheal system and its role in the evolution of the group.

The current status of hexapod phylogeny will be discussed based on a transcriptomic tree comprising 1066 genes for 1344 species of all orders and 631 families. Even though many nodes can be resolved with a high confidence, there remain some problematic splits. The recovered tree was dated with 114 calibration fossils. The resulting ages continue the trend of extremely old origins for the deeper nodes within the tree. This dated tree was used to estimate origination, extinction, and net diversification rates of families through geological time. Subsequently they were correlated with biotic and abiotic factors such as global temperature, oxygen concentration, continental fragmentation, gymnosperm and angiosperm diversity and diversity dependence.

This phylogenetic framework will be used to discuss major evolutionary questions associated with the respiratory system such as: Did the last common ancestor of the hexapods already have a tracheal system or did it evolve several times independently within the group? Which role does the respiratory system play for the ability to fly or its secondary loss? Does the tracheal system limit the maximum body size of insects?