Evolution:
Meet Tiktaalik, Tiktaalik is a tropical fish fossil that was found in the Canadian Arctic, at approximately 78° North latitude. The climate is extremely harsh for all but a few weeks of each year. During this time, the ground only thaws 6 inches below the surface, making it very difficult for large plants to grow. Consequently, there are no trees or even bushes in the high Arctic. Instead, there is tundra: a landscape of mosses, lichen, and hardy grasses that can cope with the short growing seasons and harsh temperatures of around -28°C.”
Now I’ll let you ponder this for a moment, how could a tropical “fish” possibly be found embedded in rock in an environment where temperatures in winter average -28°C? Tropical fish are effective at living in warm tropical waters but could never survive in an environment as cold as the Canadian Arctic.
Furthermore, how did the scientists who were digging specifically for Tiktaalik know where to look? Surely the best place to look for ancient fossils of a tropical fish is in the tropics? What a crazy place to look?
The answer is that fossils buried in rock are unaffected by the cold, the Tiktaalik died in the tropics, long before it made it to the Canadian Arctic, but HOW? “The answer has to do with continental drift. Three hundred and seventy-five million years ago in the Devonian, the world did not look anything like it does today. First of all, the climate was much warmer overall, so the north and south pole were not covered in ice. Secondly, the continents were not arranged in the same way as they are today. The continent Tiktaalik lived on was not located at 78° N. Instead, it was located almost entirely in the southern hemisphere. And the stream Tiktaalik probably lived in was located in the Northern part of that continent, very close to the Equator. “
Ok, that explains it, but what that doesn’t explain is how the scientists knew exactly where in the world to dig and exactly what age rock they needed to dig in, the Tiktaalik could have lived at any time in the past, how did they know to dig in 375 million year old rock? The prediction was made using modern evolutionary theory.
There are a lot of ancient tropical fish that have been discovered in similar locations to Tiktaalik, but there are many things that make Tiktaalik really special and these can be observed by looking at its physical features.
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