How does rising atmospheric CO2 affect marine organisms?

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Do Small Populations Inhibit a Species Adaptability to Warming?

Paper Reviewed
Wood, J.L.A. and Fraser, D.J. 2015. Similar plastic responses to elevated temperature among different-sized brook trout populations. Ecology 96: 1010-1019.

Noting that "the degree to which wild populations can respond to environmental change is of growing concern," Wood and Fraser (2015) investigated "plasticity to increasing temperature in a common garden experiment using eight fragmented populations of brook trout varying nearly 50-fold in census size (179-8416) and 10-fold in effective number of breeders (18-135)." And what did they thereby learn?

The two Canadian researchers report that across six early-life-history traits and three different temperatures -- one of which represented "an extreme climate warming scenario" -- they found "no evidence that small populations consistently differed from large populations either in the magnitude or extent of plastic responses to changing temperature regimes," additionally citing the comprehensive review of Kawecki (2008) in this regard.

Consequently, and in light of their own experimental observations, Wood and Fraser say that real-world "documentation of similar plastic responses of small and large populations suggests that phenotypic plasticity is not reduced as population size decreases, and that even very small populations of some species might have the ability to respond [successfully, it might be added] to climate change."

Kawecki, T.J. 2008. Adaptation to marginal habitats. Annual Review of Ecology. Evolution, and Systematics 39: 321-342.

Posted 31 July 2015