Genetic Adaptation to Extreme Environmental Change

In setting the stage for his study, Lande (2009) writes that "the primary mechanisms of phenotypic adaptation are Darwinian evolution by natural selection on genetic variation, and phenotypic plasticity through environmental influence on individual development," further stating that "rapid phenotypic adaptation may be necessary to prevent [the] extinction of modern species subject to anthropogenic global warming, especially those [species] with long generations such as large-bodied vertebrates and perennial plants."

Noting that "genetic variance in plasticity within and/or among populations has commonly been observed (Scheiner, 1993, 2002)," Lande states that he employed "quantitative genetic models of phenotypic plasticity to analyze the dynamics of phenotypic adaptation to a sudden extreme environmental change" that is "beyond the usual range of background environmental fluctuations."

In describing his (model output) findings, the Imperial College (UK) biologist reports that "during the first generation in the new environment the mean fitness suddenly drops and the mean phenotype jumps towards the new optimum phenotype by plasticity," after which "adaptation occurs in two phases." First, "rapid evolution of increased plasticity allows the mean phenotype to closely approach the new optimum," after which the new phenotype "undergoes slow genetic assimilation, with reduction in plasticity [that is] compensated by genetic evolution of reaction norm elevation in the original environment."

There is a sound observational and mechanistic basis for believing that Earth's flora and fauna are genetically capable of meeting the challenge of coping with the type of rapid CO₂-induced global warming that climate alarmists contend will drive innumerable plant and animal species to extinction.

Additional References
Scheiner, S.M. 1993. Genetics and evolution of phenotypic plasticity. Annual Review of Ecology and Systematics 24: 35-68.

Scheiner, S.M. 2002. Selection experiments and the study of phenotypic plasticity. Journal of Evolutionary Biology 15: 889-898.