Data from: Mechanical sensitivity reveals evolutionary dynamics of mechanical systems

A classic question in evolutionary biology is how form–function
relationships promote or limit diversification. Mechanical metrics, such
as kinematic transmission (KT) in linkage systems, are useful tools for
examining the evolution of form and function in a comparative context. The
convergence of disparate systems on equivalent metric values (mechanical
equivalence) has been highlighted as a source of potential morphological
diversity under the assumption that morphology can evolve with minimal
impact on function. However, this assumption does not account for
mechanical sensitivity—the sensitivity of the metric to morphological
changes in individual components of a structure. We examined the
diversification of a four-bar linkage system in mantis shrimp
(Stomatopoda), and found evidence for both mechanical equivalence and
differential mechanical sensitivity. KT exhibited variable correlations
with individual linkage components, highlighting the components that
influence KT evolution, and the components that are free to evolve
independently from KT and thereby contribute to the observed pattern of
mechanical equivalence. Determining the mechanical sensitivity in a system
leads to a deeper understanding of both functional convergence and
morphological diversification. This study illustrates the importance of
multi-level analyses in delineating the factors that limit and promote
diversification in form–function systems.