The genetics of a species of skunk may have more factors because of the Ice Age climate and not the geological barriers that are usually believed by scientists. This is the conclusion made by researchers in a recent study about the foul-smelling animals.
In a new paper published in Ecology and Evolution titled "Phylogeography of a widespread small carnivore, the western spotted skunk (Spilogale gracilis) reveals temporally variable signatures of isolation across western North America," researchers have analyzed the DNA of the western spotted skunk and learned that the climate during Ice Age played a crucial role in their evolution. Adam Ferguson, the lead author of the study, said that by analyzing their DNA, they believe that it was the changing climates that isolated them and gave rise to the sub-division of the animal.
"Over the past million years, changing climates isolated groups of spotted skunks in regions with suitable abiotic conditions, giving rise to genetic subdivisions that we still see today," he said. Ferguson also serves as the Collections Manager of Mammals at The Field Museum in Chicago. He is also an affiliate of Texas Tech University.
Western spotted skunks could be identified from the other types of skunks by looking at their coats and the way they spray their known foul smell. Their coats are an almost maze-like pattern of black and white swirls and when they spray, they usually do a hand-stand, hind legs and fluffy tail in the air. Most of them can be found in Western US and Mexico.
In an article published in Science Daily, the sub-groups of the western spotted skunk develop when a species is split up by geography. For example, if a species is separated by a mountain range, the groups on either side of the mountain may wind up splitting off from each other genetically.
However, researchers observed that these sub-groups of the skunk are not driven by geographical barriers. Instead, it could be attributed to the climate of the place they go, relating it more to the Ice Age climate change.
"Western spotted skunks have been around for a million years, since the Pleistocene Ice Age," Ferguson said. Furthermore, he explained that during the Ice Age, the majority of the western part of North America was covered with glaciers and these were deemed as suitable climates for the skunks separated by patches of unsuitable climates.
They observed when analyzing today's skunks, they found out that the three sub-groups responded to different climate refugia. "That means that for spotted skunk evolution, climate change appears to have been a more important factor than geographical barriers," Ferguson said.
