Last time around, we brought forth evidence against organismal “dumbness”—the notion that species found only in defined climatic environments will go extinct if the climate changes beyond their range. We picked on cute little Nemo, and “found,” much like in the animation, that his kind (Amphiprion ocellaris) could actually survive far beyond their somewhat circumscribed tropical reef climate.
The key was the notion of plasticity—the concept that, despite being linked to a fixed genetic compliment, or genotype, the products of those genes (the “phenotype”) changed along with the environment, allowing organisms some degree of insurance against climate change. How this comes about through evolution remains a mystery, though we may occasionally indulge in a bit of high speculation.
“Science,” according to the late, great philosopher Karl Popper, is comprised of theories that are capable of making what he called “difficult predictions.” The notion that gravity bends light would be one of those made by relativity, and it was shown to be true by Sir Arthur Eddington in the 1919 total solar eclipse. It just happened to be in totality in the Pleiades star cluster (also the corporate logo of Subaru), and, sure enough, the stars closest to the eclipsed sun’s limb apparently moved towards it when compared to their “normal” positions.
So we have been interested in a truly difficult test of phenotypic plasticity, and we think we found one.
How about a clam that lives in the bottom of the great Southern Ocean surrounding Antarctica? Specifically, the burrowing clam Laternula elliptica. According to a recent (2017) paper by Catherine Waller of the University of Hull (in the, perhaps temporarily, United Kingdom) “75 percent of the recorded specimens [of L. elliptica] are from localities shallower than 100 m,” where the populations are exposed to “low and stable water temperatures in the range of -1.9 to +1.8 °C” (the remaining 25 percent inhabit cooler waters of the continental slope down to ~700m).