The need to bridge concepts of development in the life sciences
Development is a key concept in biology. Early on, it was used not only for organ development and the process of ontogenesis but also for phylogenetic change (Toepfer, 2011, p. 392).1 Following the rediscovery of Mendel, the rise of genetics, and the Synthetic Theory of Evolution in the early 20th century, phylogenetic and ontogenetic development were considered separated processes; moreover, the latter was considered a result of the former. However, phylogenetic processes are studied at the population level, based on transmission of genes and random mutations, while ontogenetic processes are studied at the individual level, based on self-differentiation and induction including imprinting and learning. How both concepts of development can be integrated within a common theoretical framework and methodology has marked a key question for developmental science ever since. Today, we observe a new rise of developmental thinking in some areas of the life sciences, such as epigenetics (e.g. Fagiolini, Jensen, & Champagne, 2009) and developmental neuroscience (e.g. Munakata, Casey, & Diamond, 2004; Mason, 2009). The question of how to integrate developmental data collected at a population level and individual level remains a major challenge for these emerging research fields. This is especially the case for research concerned with psychobiological development.