Global Warming Impact: Climate Change Elicited Different Response Across Ice Age Vertebrate Species

A new study revealed that different vertebrate species in the eastern United States have responded to the effects of climate change over the last 500,000 years differently.

The study, published in the journal Ecology Letters, suggests that the animal populations during the expansion and contraction of massive glaciers across the region have been affected in different ways and different times.

"We need to move beyond viewing communities as single units," explained Brian T. Smith, an assistant curator in the American Museum of Natural History's Department of Ornithology and co-author of the study, in a press release. "Some species will respond in one way and others will respond in other ways. And there are many external historical, biological, and stochastic factors that will influence how populations respond to global warming."

For the study, the researchers analyzed the genomes of tetrapods, such as snakes, lizards, mammals, birds, turtles and frogs. By focusing the on the historical population sizes of tetrapods, the researchers were able to model the likelihood of the populations to grow or shrink as response to climate change.

The researchers noted that increase in genetic differences among the population signals an expansion in their population, while lesser genetic differences mean smaller populations. Previous theory suggests that local populations of animals will "synchronously" as the glacier recedes.

However, the researchers did not find any evidence that different animal populations have similar response to the changing climate. About 25 percent of the populations experience negative response to the climate change. These populations felt a dramatic decline in their numbers. On the other, about 75 percent of the animals went through a population expansion. Out of those expanding lineages, only 50 percent expanded together.

With their findings, the researchers warned the scientist not to view certain animal population communities as a single synchronized unit. The researchers noted that the contracting and expanding of a huge glacier could affect everyone. However, different animal population may have different response to such events.