Hormesis on life-history traits: is there such thing as a free lunch?
Source: Ecotoxicology, Volume 22, Number 2, March 2013 , pp. 263-270(8)
Abstract:The term “hormesis” is used to describe dose–response relationships where the response is reversed between low and high doses of a stressor (generally, stimulation at low doses and inhibition at high ones). A mechanistic explanation is needed to interpret the relevance of such responses, but there does not appear to be a single universal mechanism underlying hormesis. When the endpoint is a life-history trait such as growth or reproduction, a stimulation of the response comes with costs in terms of resources. Organisms have to obey the conservation laws for mass and energy; there is no such thing as a free lunch. Based on the principles of Dynamic Energy Budget theory, we introduce three categories of explanations for hormesis that obey the conservation laws: acquisition (i.e., increasing the input of energy into the individual), allocation (i.e., rearranging the energy flows over various traits) and medication (e.g., the stressor is an essential element or acts as a cure for a disease or infection). In this discussion paper, we illustrate these explanations with cases where they might apply, and elaborate on the potential consequences for field populations.
Document Type: Research Article
Affiliations: 1: Department of Theoretical Biology, VU University Amsterdam, de Boelelaan 1085, 1081 HV, Amsterdam, the Netherlands, Email: email@example.com 2: INRA, Equipe Ecotoxicologie et Qualité des Milieux Aquatiques, UMR985 Ecologie et Santé des Ecosystèmes, INRA-Agrocampus Ouest, 65 rue de Saint Brieuc, 35000, Rennes, France
Publication date: 2013-03-01