Variation in toxicity of a current-use insecticide among resurrected Daphnia pulicaria genotypes

Abstract

This study examined how genotypes of Daphnia pulicaria from a single population, separated by thousands of generations of evolution in the wild, differ in their sensitivity to a novel anthropogenic stressor. These genotypes were resurrected from preserved resting eggs isolated from sediments belonging to three time periods: 2002-2008, 1967-1977, and 1301-1646 A.D. Toxicity of the organophosphate insecticide chlorpyrifos was determined through a series of acute toxicity tests. There was a significant dose-response effect in all genotypes studied. Moreover, significant variation in toxicity among genotypes within each time period was detected. Importantly, a significant effect of time period on sensitivity to chlorpyrifos was found. Analysis of the median effect concentrations (EC50s) for genotypes within each time period indicated that the 1301-1646 genotypes were 2.7 times more sensitive than the 1967-1977 genotypes. This trend may be partially explained by microevolutionary shifts in response to cultural eutrophication.

Resurrected ‘ancient’ Daphnia genotypes show reduced thermal stress tolerance compared to modern descendants

“…Rising temperatures can lead to microevolutionary responses in populations of Daphnia that can shift a variety of traits including phenology [ 18 ], physiology (e.g. respiration, haemoglobin production [ 19 ]); among other physiological traits [ 7 , 16 , 18 , 20 ], behaviour [ 19 , 21 ], life history [ 10 , 22 ] as well as thermal tolerance [ 23 – 25 ]. Previous work has documented increased levels of heat shock protein production in Daphnia as a response to biotic (i.e.…”

Resurrection ecology and its utility in ecotoxicology

“…This lake has a history of cultural eutrophication, evidenced by a drastic increase in sediment P concurrent with European colonization of the area. Simpson et al () used this system to evaluate how susceptibility to an insecticide has changed over time in this population. They tested Daphnia clones resurrected from 3 time points: 1 precolonization (1301–1646), and 2 postcolonization (1967–1977, 2002–2008).…”

“…They are an excellent complement to spatial approaches, and can yield valuable information regarding the justification of assumptions inherent in spatial studies. Additionally, they have the potential to inform predictions of how a population might respond to future challenges (Orsini et al ; Simpson et al ). We posit that the unique and powerful approach of resurrection ecology will be useful for environmental scientists interested in understanding the ecoevolutionary consequences of contaminants and will aid in forecasting the fate of biota.…”

Learned Discourse: Timely Scientific Opinions

“…This lake has a history of cultural eutrophication, evidenced by a drastic increase in sediment P concurrent with European colonization of the area. Simpson et al (2015) used this system to evaluate how susceptibility to an insecticide has changed over time in this population. They tested Daphnia clones resurrected from 3 time points: 1 precolonization (1301-1646), and 2 postcolonization (1967)(1968)(1969)(1970)(1971)(1972)(1973)(1974)(1975)(1976)(1977)(2002)(2003)(2004)(2005)(2006)(2007)(2008).…”

“…They are an excellent complement to spatial approaches, and can yield valuable information regarding the justification of assumptions inherent in spatial studies. Additionally, they have the potential to inform predictions of how a population might respond to future challenges (Orsini et al 2013;Simpson et al 2015). We posit that the unique and powerful approach of resurrection ecology will be useful for environmental scientists interested in understanding the ecoevolutionary consequences of contaminants and will aid in forecasting the fate of biota.…”