Spotted salamander evolution
Spotted salamanders exposed to contaminated roadside ponds are adapting to their toxic environments by evolving rapidly, according to a Yale paper in Scientific Reports. Salamanders breeding in roadside ponds are exposed to a host of contaminants from road runoff, most notably sodium chloride from road salt, which reaches average concentrations of 70 times higher than that of woodland ponds located hundreds of feet from the road. F&ES doctoral student Steven Brady, who authored the study, observed salamanders in ten ponds—five roadside and five woodland—in northeastern Connecticut, and found that the ones in roadside ponds have higher mortality, grow at a slower rate, and are more likely to develop L-shaped spines and other disfigurements. In addition, he found that only 56 percent of salamander eggs survive the first ten weeks of development, whereas 87 percent survive in the woodland ponds. But, Brady says, the salamanders that survive in the ponds year after year appear to have adapted to the harsh conditions and do “substantially better” than the woodland ones when they’re raised together.
Cyclones to cause greater damage
Yale and MIT researchers have calculated that by the year 2100, tropical cyclones will have caused $109 billion in damages. This figure represents an increased vulnerability from population and especially economic growth, as well as the effects from climate change. Using a tropical cyclone integrated assessment model along with climate models, the researchers were able to predict how the frequency, intensity, and location of tropical cyclones change in the seven oceans, and then applied historical data to estimate damages. The authors based their estimates on a future global population of 9 billion and an annual increase of about 3 percent in gross world product until 2100. The paper was published in Nature Climate Change.
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