Distribution of Marsupials
The history of marsupials also provides an example of how the theories of evolution and continental drift can be combined to make predictions about what will be found in the fossil record. The earliest marsupial fossils are about 80 million years old and found in North America; by 40 million years ago fossils show that they could be found throughout South America, but there is no evidence of them in Australia, where they now predominate, until about 30 million years ago. The theory of evolution predicts that the Australian marsupials must be descended from the older ones found in the Americas. The theory of continental drift says that between 30 and 40 million years ago South America and Australia were still part of the Southern hemisphere super continent of Gondwana and that they were connected by land that is now part of Antarctica. Therefore combining the two theories scientists predicted that marsupials migrated from what is now South America across what is now Antarctica to what is now Australia between 40 and 30 million years ago. This hypothesis led paleontologists to Antarctica to look for marsupial fossils of the appropriate age. After years of searching they found, starting in 1982, fossils on Seymour Island off the coast of the Antarctic Peninsula of more than a dozen marsupial species that lived 35–40 million years ago.
Read more about this topic: Evidence Of Common Descent, Evidence From Geographical Distribution, Specific Examples
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