 During the twentieth century these partings of development and evolution led to statements such as: “Problems concerned with the orderly development of the individual are unrelated to those of the evolution of organisms through time” (Wallace 1986: 149). However, such statements were also targeted by a number of critics. For example, the exclusion of developmental biology from the modern synthesis (Harrison 1937; De Beer 1954; Waddington 1957; Hamburger 1980), the explanatory autocracy of the adaptationist program in evolutionary biology (Gould &amp; Lewontin 1979), and the omission of a satisfying theory of evolutionary novelty, in which development would play a role (Goldschmidt 1940), have been criticized. Not least due to this rejection of developmental perspectives, evolutionary theory has been blamed to constrain the direction of research in evolutionary biology (Provine 1989). In fact, throughout the twentieth century a number of theories have been put forward, which argue that due to the partial independence of genetic and phenotypic variation, evolutionary research should put more emphasis on how the changes in developmental and behavioral patterns might drive or bias evolutionary change. This includes cases of ‘canalized’ developmental pathway which are maintained, even though the genotype or the environment might have changed to some degree (Waddington 1957; see also Nijhout 2002; Gilbert &amp; Epel 2015; Sultan 2015). In addition, studies of phenotypic plasticity showed that a trait of an organism can react to an environmental input in various ways, and that the genome codes for a wide range of potential phenotypes (Waddington 1942; Nijhout 1990; Pigliucci 2001). The evolutionary relevance of these findings was emphasized by studies that investigated how the range of variation changes from a plastic trait to a fixed or canalized one over the course of generations (Suzuki and Nijhout 2008; West-Eberhard 2003; B. Baker et al. 2019). What is more, according to the so-called ‘Baldwin effect,’ learned behavioral patterns (e.g., the acclimatization to a new stressor) that were initially rather plastic, can affect the reproductive success of individuals and thus, across generations and through natural selection, be gradually incorporated into the genetic and epigenetic makeup of a species (Baldwin 1896; Simpson 1953; Piaget 1976 [1978]; Newman 2002). While some of these developmental perspectives on evolution were consistent with the population genetic framework of evolutionary biology and were, in fact, gradually incorporated into evolutionary thought, others posed more serious challenges for theoretical integration.