In 1961, Ernst Mayr published a highly influential article on the nature of causation in biology, in which he distinguished between proximate and ultimate causes. Mayr argued that proximate causes (e.g. physiological factors) and ultimate causes (e.g. natural selection) addressed distinct ‘how’ and ‘why’ questions and were not competing alternatives. That distinction retains explanatory value today. However, the adoption of Mayr’s heuristic led to the widespread belief that ontogenetic processes are irrelevant to evolutionary questions, a belief that has (1) hindered (...) progress within evolutionary biology, (2) forged divisions between evolutionary biology and adjacent disciplines and (3) obstructed several contemporary debates in biology. Here we expand on our earlier (Laland et al. in Science 334:1512–1516, 2011) argument that Mayr’s dichotomous formulation has now run its useful course, and that evolutionary biology would be better served by a concept of reciprocal causation, in which causation is perceived to cycle through biological systems recursively. We further suggest that a newer evolutionary synthesis is unlikely to emerge without this change in thinking about causation. (shrink)

Sociological, economic and evolutionary paradigms of human agency have often seen social agents either as the rational controllers of their fate or as marionettes on the strings of historical, functional or adaptive necessity. They found it therefore difficult to account for the variability, intentionality and creativity of human behaviour and for its frequently redundant or harmful results. This paper argues that human agency is a product of evolution, but that genetic variation and inheritance can only provide a limited explanation of (...) its complex nature. The primary evolutionary problem which human agents face while they are alive is not to adapt to stable environments, but to respond flexibly and creatively to a contingent, uncertain world. Variation and selection therefore take two connected but distinct forms, one external, genetic, and inherited across generations, the other internal and cognitive, and operating during the lifetime of individuals. An examination of this lived part of evolution provides a better understanding of key properties of agency. (shrink)