Data from: Functional innovation promotes diversification of form in the evolution of an ultrafast trap-jaw mechanism

Evolutionary innovations underlie the rise of diversity and complexity—the
two long-term trends in the history of life. How does natural selection
redesign multiple interacting parts to achieve a new emergent function? We
investigated the evolution of a biomechanical innovation, the latch-spring
mechanism of trap-jaw ants, to address two outstanding evolutionary
problems: how form and function change in a system during the evolution of
new complex traits, and whether such innovations and the diversity they
beget are repeatable in time and space. Using a new phylogenetic
reconstruction of 470 species, and X-ray microtomography and high-speed
videography of representative taxa, we found the trap-jaw mechanism
evolved independently 7–10 times in a single ant genus (Strumigenys),
resulting in the repeated evolution of diverse forms on different
continents. The trap mechanism facilitates a 6–7 order of magnitude
greater mandible acceleration relative to simpler ancestors, currently the
fastest recorded acceleration of a resettable animal movement. We found
that most morphological diversification occurred after evolution of
latch-spring mechanisms, which evolved via minor realignments of mouthpart
structures.  This finding, whereby incremental changes in form
lead to a change of function, followed by large morphological
reorganization around the new function, provides a model for understanding
the evolution of complex biomechanical traits, as well as insights into
why such innovations often happen repeatedly.