According to Dr. Somero, "Tropical porcelain crabs, which live at high temperatures, live right near the edge of their thermal tolerance range, and they have little ability to further increase their thermal tolerance by acclimation." Therefore, even though this tropical crab species can handle higher temperatures compared to the temperate crab species, the tropical species is close to reaching the tipping point for coping with additional increases in temperature. Thus, the tropical crabs have less of a margin for adaptation to warm climates while the temperate counterparts have more room to adapt.
"Researchers can predict that tropical species of porcelain crabs will be more vulnerable to climate change than temperate ones," said Dr. Somero. "Furthermore, the lessons we've learned from studying these marine crabs appear to apply not only to other marine animals, but also to terrestrial species."
Protein and Adaptation to Climate Change
The Somero team is also looking at the role proteins play in an organism's ability to adapt to climate change. Proteins, which provide much of the structure of organisms and drive all metabolic reactions, are highly sensitive to temperature. The abilities of proteins to evolve rapidly in the face of climate change will affect a species' chances of survival. "If proteins don't adapt, organisms will function at a sub-par level," said Dr. Somero. "Individual organisms may not die immediately, but over time, entire populations can die off."
The more abundant the number of adaptive sites that exist on a protein, the more easily that protein can undergo adaptive change. Comparative studies of proteins common to diverse species of fish and invertebrates have shown that only a single change in structure (one amino acid is substituted for another) can be sufficient to adapt a protein t
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American Physiological Society