Evolution: The Cope's treefrog and the grey treefrog looks identical, so much so, that even their DNA is almost identical. Both these frogs were at one point the same species. Some Cope's treefrogs were born with a mutation where instead of having the normal two sets of chromosomes, they had four. Those with four sets were able to breed with other individuals with the same mutation. They could not however, successfully breed with those with only two sets of chromosomes, separating them genetically. These frogs developed in genetic isolation from the Cope's treefrogs to the point that their calls became slower and lower pitched while physically, they remained the same. These became the grey treefrogs, also known as the tetraploid grey treefrog and can only be identified through their genetics, range, and of course, their call.
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Range: Grey treefrogs and Cope's treefrogs overlap in range in a few areas although Cope's treefrogs live predominately in the south eastern United States where grey treefrogs cannot be found, likely due to the cope's treefrog's higher tolerance for dryer conditions. They can also be found from Texas, north into southern Manitoba. Recently, the Cope's treefrog has been discovered in north western Ontario with a very small range in the Lake of the Woods area, close to the Minnesota U.S.A. land boarder.
Sources:
"Cope's Gray Treefrog." Canadian Herpetological Society, 2021, canadianherpetology.ca/species/species_page.html?cname=Cope%27s%20Gray%20Treefrog. Accessed 10 Nov. 2021. "Cope's Treefrog." Nature Watch, 2021, www.naturewatch.ca/frogwatch/copes-treefrog/. Accessed 10 Nov. 2021. Powell, Robert, et al. Peterson Field Guide to Reptiles and Amphibians. 4th ed., Houghton Mifflin Harcourt Publishing Company, 2016. Vrijenhoek, Robert C. "Polyploid Hybrids: Multiple Origins of a Treefrog Species." Science Direct, Current Biology, 4 Apr. 2006, www.sciencedirect.com/science/article/pii/S096098220601253X. Accessed 4 Nov. 2021. |