A great deal of progress has recently been made in characterizing the “mechanisms of aging.” A comparison with the mechanisms of development shows that the two sets of mechanisms are different; nevertheless, mechanisms of aging are conditioned by what happens during development. Aging and development also share some characteristics, such as a similar difficulty in attributing a precise temporal boundary to these processes. Other characteristics seem more specific to aging, such as the role of external (to the organism) and stochastic (...) events in its progression. In fact, both development and aging are historical processes with a mixture of stochastic events and deterministic processes, the ratio of the two being different in each process. Therefore, it is concluded that aging does not fit with a broad, lifelong conception of development. (shrink)

Since the 1950s, the common view of development has been internalist: development is seen as the result of the unfolding of potentialities already present in the egg cell. In this article, I show that this view is incorrect because of the crucial influence of the environment on development. I focus on a fascinating example, that of the role played by symbioses in development, especially bacterial symbioses, a phenomenon found in virtually all organisms (plants, invertebrates, and vertebrates). I claim that we (...) must consequently modify our conception of the boundaries of the developing entity, and I show how immunology can help us in accomplishing this task. I conclude that the developing entity encompasses many elements traditionally seen as “foreign,” while I reject the idea that there is no possible distinction between the organism and its environment. (shrink)

This special issue of Biological Theory is focused on development; it raises the problem of the temporal and spatial boundaries of development. From a temporal point of view, when does development start and stop? From a spatial point of view, what is it exactly that "develops", and is it possible to delineate clearly the developing entity? This issue explores the possible answers to these questions, and thus sheds light on the definition of development itself.

Evo-Devo exhibits a plurality of scientific “cultures” of practice and theory. When are the cultures acting—individually or collectively—in ways that actually move research forward, empirically, theoretically, and ethically? When do they become imperialistic, in the sense of excluding and subordinating other cultures? This chapter identifies six cultures – three /styles/ (mathematical modeling, mechanism, and history) and three /paradigms/ (adaptationism, structuralism, and cladism). The key assumptions standing behind, under, or within each of these cultures are explored. Characterizing the internal structure of (...) the cultures is necessary for understanding how they collaborate or compete, and how they are fragmented or integrated, in the rich interdisciplinary /trading zone/ (Galison 1997) of Evo-Devo. Evo-Devo is an important example of how science can progress through a radical plurality of perspectives and cultures. (shrink)