Recently, in class we have been discussing plasticity in a variety of different environments and functions. Phenotypic plasticity plays a very important role in organisms ability to respond to new environments and situations. I read a review the other day from Frontiers in Genetics, discussing the impact of genomics on developmental plasticity, and the effects that this plasticity can have upon adaptation in later life.
One of the most interesting things about the review for me was the discussion about the potential mitigating effects of plasticity on the detrimental impacts of future climate change. As climate change progresses, it is likely that temperatures will fluctuate, and many biomes will change drastically in a relatively short period of time. As these changes occur, organisms will have to adapt, die out, or migrate. When organisms are forced to adapt it can be an enormous benefit to be more "plastic" in terms of traits. Greater plasticity allows an organism to survive in a greater range of environments and allows them to endure a greater variety of conditions. One particular example of this is when a change in climate alters the visual environment, resulting in an organism's camouflage being less effective than it was previously. A greater degree of plasticity in camouflage variety can help a predator catch prey, or a prey species avoid predators in a new environment. If a species does not have this plasticity in appearance they can easily appear out of place, and are much more easily spotted. And while organisms may already have to adapt to new climates and environments, in the future it will be a much greater requirement, and the pace at which changes occur will be much greater. Those species that cannot change will likely vanish. Greater degrees of plasticity are often genetic and heritable, so that more plastic parents will have more plastic offspring. By this process the whole population will generally become more and more plastic in a rapidly changing environment.
Lafuente E, Beldade P. 2019. Genomics of Developmental Plasticity in Animals. Frontiers in Genetics 10, doi: 10.3389/fgene.2019.00720
I completely agree, with the climate changing many species will have to adapt (increase plasticity), migrate, or die. There has to be costs to plasticity though, if not then species will be selected for maximum plasticity which we don't observe. Species have select ranges of plasticity to specific stressors, so what is the cost? T. J. DeWitt tested phenotypic cost in freshwater snails where he found growth rates of snail shell sizes were inversely related to their genetic potential for a plastic response to predator presence. He has written other papers as well questioning the costs of phenotypic plasticity, where there are a number of theories. One prevailing theory though is the energetic cost needed to maintain sensory and regulatory machinery needed for plasticity. As to the direct costs of these, there is a lot of contention. Different taxa have different ways of maintaining these tools for plasticity. It will take a lot more research to parse these costs out across the animal kingdom.
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