Inbreeding depression in adaptive plasticity under predation risk in a freshwater snail

Abstract

While much attention has been paid to the effects of inbreeding on fitness, this has mostly come from a genetic perspective. Consequently, the interaction between inbreeding and the environment is less well understood. To understand the effects of inbreeding in natural populations where environmental conditions are variable, we need to examine not only how the effects of inbreeding change among environments but also how inbreeding may affect the ability to respond to environmental conditions (i.e. phenotypic plasticity). We reared selfed and outcrossed hermaphroditic snails (Physa acuta) in the presence and absence of chemical cues from predatory crayfish and quantified expression of an inducible defence, an adaptively plastic response to predation risk. Overall, inbred snails exhibited reduced defences, but more importantly, inbreeding reduced the expression of predator-induced adaptive plasticity. Inbreeding depression in defensive morphology was 26 per cent and inbreeding depression in the plasticity of this trait was 48 per cent. Inbreeding depression in adaptive plasticity may be important to understanding the effects of inbreeding in nature.

Interplay between habitat fragmentation and climate change: inbreeding affects the response to thermal stress in Drosophila melanogaster

“…Whereas adaptive plasticity is crucial for a population to cope with the imposed stress in the short term, our results show that such responses can be significantly hampered by inbreeding. This idea is supported by recent data on the effect of inbreeding on the predator-induced adaptive responses in a freshwater snail (Auld & Relyea 2010). As such, inbreeding enhances the harmful effects of stress on populations.…”

Slow inbred lines of Drosophila melanogaster express as much inbreeding depression as fast inbred lines under semi-natural conditions

“…they are more plastic due to their higher degree of heterozygosity (Lerner 1954;Fowler and Whitlock 1999;Auld and Relyea 2010). However our results show that fitness consequences of stress seem to be independent of inbreeding rate, and therefore we have no evidence that slow inbred lines should be better able to cope with environmental change compared to fast inbred lines through adaptive plastic responses.…”

Genetic erosion in the snailLittoraria subvittata(Reid, 1986) due to mangrove deforestation

“…Gene flow among and within populations is an important part of the maintenance of species integrity and genetic diversity, and can be affected by both natural and anthropogenic factors (Banks et al, 2013). Altered genetic diversity can influence the fitness of populations, decreasing the capability of species to adapt to environmental change (Keller & Waller, 2002;Auld & Relyea, 2010). The analysis of mitochondrial DNA (mtDNA) sequence data is a powerful tool for tracing the recent evolutionary history of marine gastropods in terms of bottlenecks, population expansion or contraction, and founder effects (Crandall et al, 2007;Duda & Lee, 2009;Madeira et al, 2012;Haupt, Micheli & Palumbi, 2013).…”