 By building on the latter, more problematic set of approaches (especially in recent years), evolutionary theory has been facing calls from developmentally oriented biologists and philosophers of biology to widen the standard explanatory and methodological approaches on evolution (Bonner 1958; Alberch 1982; Bonner 1982; Raff &amp; Kaufman 1983; Gilbert, Opitz, &amp; Raff 1996; Schlichting &amp; Pigliucci 1998; West-Eberhard 2003; G. Müller 2007; Pigliucci &amp; Müller 2010; Bateson &amp; Gluckman 2011; Jablonka &amp; Lamb 2014; Laland et al. 2014, 2015; Gilbert &amp; Epel 2015; G. Müller 2017; for discussion, see Huneman &amp; Walsh 2017; Fábregas-Tejeda &amp; Vergara-Silva 2018; Baedke et al. 2020b). They argue that evolutionary change should not only or primarily be investigated and explained as a change in genotype frequencies in populations but (also) on the level of the developing and acting individual. The underlying idea is that phenotypic variation and the flexibility of organisms’ responses to environmental cues may introduce non-random variation and thus may bias and/or direct morphological evolution to some degree. This includes not only environmentally induced changes in regulatory processes but also the physical constraints of the developing embryo. By focusing on these phenomena, Kevin Laland and colleagues (2014: 161) state: “An alternative vision of evolution is beginning to crystallize, in which the processes by which organisms grow and develop are recognized as causes of evolution”. Others have argued that genes are probably more often followers in evolution than leaders (West-Eberhard 2003, 2005). In other words, the environmentally responsive, developing and acting organism takes the lead. It introduces in a non-random way new phenotypes into populations that are subsequently stabilized by genes.