Ecological Developmental Biology: Developmental Biology Meets the Real World

Abstract

The production of phenotype is regulated by differential gene expression. However, the regulators of gene expression need not all reside within the embryo. Environmental factors, such as temperature, photoperiod, diet, population density, or the presence of predators, can produce specific phenotypes, presumably by altering gene-expression patterns. The field of ecological developmental biology seeks to look at development in the real world of predators, competitors, and changing seasons. Ecological concerns had played a major role in the formation of experimental embryology, and they are returning as the need for knowledge about the effects of environmental change on embryos and larvae becomes crucial. This essay reviews some of the areas of ecological developmental biology, concentrating on new studies of amphibia and Homo.

Juvenile hormone titre and related gene expression during the change of reproductive modes in the pea aphid

“…In many organisms, responses to short-term local environmental changes are often accomplished via phenotypic plasticity, when a single genotype produces various phenotypes depending on the environment (Gilbert, 2001;West-Eberhard, 2003). Phenotypic plasticity producing discrete phenotypes from the same genotype is called polyphenism (Nijhout, 1999).…”

Critical period: A history of the transition from questions of when, to what, to how

“…That is, the ''how'' of development is thought to require reduction to a physiological or molecular level of biological investigation. However, as we become more sophisticated in the understanding of organism-environment interaction in behavioral development, we will begin to achieve greater understanding of the pathways responsible for individual differences and inter-individual similarities of psychological characteristics (c.f., Gilbert, 2001). Such understanding will provide us with greater control of our offspring's destiny and greater responsibility for our exercise of such control.…”

Evolutionary Developmental Biology and the Limits of Philosophical Accounts of Mechanistic Explanation

“…Though causally enmeshed with gene activity, epigenetic processes are any influences on development that do not solely depend on the expression of genes, for example biophysical interactions among cells, mechanical influences on tissues, and physical and biochemical processes of self-organization. The environment can also influence epigenetic-developmental processes (Gonzalez et al 2011) and this is particularly important in the case of phenotypic plasticity, the ability of organisms to develop several phenotypic outcomes depending on environmental factors (Gilbert 2001;Whitman and Agrawal 2009). Phenotypic plasticity can be significant for the evolution of novel morphological traits, and shows that sometimes morphological evolution is initiated by phenotypic change, with genetic change only subsequently taking place (Palmer 2004;West-Eberhard 2003.…”

“…While these are instances of continuous phenotypic variation, there are many cases of plasticity consisting in the development of two (or more) qualitatively distinct alternative morphologies, so-called polyphenisms (Gilbert 2001;Whitman and Agrawal 2009). Daphnia (waterfleas) have two morphs.…”