 With respect to the concept of mechanism in developmental evolution, Brigandt (2015) highlights that some mechanistic explanations in evo-devo – like those on how development biases evolution (Radersma et al. forthcoming), how novel variation arises through developmental plasticity (Pigliucci 2001, Gilbert 2006), and how organisms generate heritable, adaptive phenotypic variation (evolvability; see Brown 2014) – significantly expand the standard analysis of decomposition and localization by dynamical models (see also Bechtel &amp; Abrahamsen 2010; Brigandt 2013; Baedke 2020). These models allow predicting the dynamics of developing systems. After decomposing a system and identifying causal contributions of parts or sub-systems, dynamical models help to demonstrate how these contributions operate together to bring about a whole system’s behavior. In this way, they answer how developmental mechanisms create evolutionary relevant qualitative changes in phenotypic properties, like robustness, phenotypic plasticity, and modularity, through underlying quantitative changes in their component parts and activities. One classical example of this are mathematical models on the robustness of spatial pattering and segmentation in Drosophila. They provide quantitative information about the interaction of underlying gene network components, including, for example, gene transcription rates and decay rates of gene products (von Dassow et al. 2000).