Up-and-coming scientists, particularly those holding an environmental biology degree, are becoming increasingly familiar with the workings of Earth’s complex atmosphere. And they’re discovering mounting evidence that the life forms on the planet are symbiotically related to the environmental safety net that surrounds it. What is also becoming apparent is that smaller life forms have a biological advantage when it comes to adapting to climate and temperature changes. An alarming new study found that fungus adjusted to the sudden change in temperature nearly ten times faster than frogs, possibly spelling danger for frogs and other creatures as the planet continues to warm.
Adapting to Climate Change – Size Matters
Tapeworms and parasites have short life spans and reproduce quickly. Adaptations to climactic and other changes typically evolve over a number of generations. These smaller organisms will adapt more quickly than reptiles, amphibians or mammals that reproduce once or twice a year.
A recent experiment conducted on Cuban tree frogs highlighted this disparity. The frogs were exposed to a sometimes deadly chytrid fungus, the Batrachochytrium dendrobatidis. Scientists found that frogs living with fairly consistent daily temperature changes were better able to resist infection. Unpredictable spikes or drops in temperature increased infections. Scientists also noticed that the fungus adjusted to the sudden change in temperature nearly ten times faster than the frogs.
Spreading Viruses in a Warmer World
Scientists speculate that amphibians, reptiles and fish, all cold-blooded organisms, will be more susceptible to parasitic infection than warm blooded animals, simply because they are not able to regulate their internal temperature in the same fashion.
Bullfrogs have shown to be susceptible to the chytrid fungus, but in their case the infection is not fatal. Instead these amphibians act as carriers for the infection. Since bullfrogs are shipped to various locations around the world as a food source, the chytrid fungus is being spread to those locales.
The threat is that the fungus will be introduced into the local frog population, not yet adapted to an infection usually found in hotter climates. Native frog species would be more susceptible to fatal infections. As global warming progresses, the disparity between the adaptability of the fungus and that of the local frog populations is expected to increase.
Scientists in the United States took samples from bullfrogs shipped to Asian markets in seven different cities. Of the frogs sampled, 41 percent were found to be infected with the chytrid fungus. Most of the bullfrogs shipped into the United States came from Ecuador, Brazil and Taiwan, all countries with warmer and more humid climates than most of North America.
The same team of scientist took samples in Brazil, both at frog farms and in wild populations in the Atlantic Forest. The chytrid fungus had indeed mutated into four different strains of Batrachochytrium dendrobatidis. One of those strains was a perfect match for samples taken from a bullfrog in Michigan, originally shipped from the Atlantic Forest area. A comparison between biological samples taken in both Brazil and Japan showed that the chytrid fungus had already crossed the Pacific Ocean.
It is theorized that the live trade of these frogs has already introduced the chytrid fungus on a global scale. Curtailing this practice may not eliminate the fungus from areas already infected, but it may help contain the chytrid within those areas. Global warming and the expected increase in average temperatures worldwide will most likely make it harder to contain this highly adaptable organism.