Great Transformations Summary
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“basic human need to as who we are, where did we come from, how did we get here, why do we look the way we do?” The video started off by asking questions and stating facts about evolution saying that humans had just arrived on earth. Neil Shubin from Chicago University compared 4 billion years to an hour. He said the first 50 minutes was spent on microbes and single celled organisms, then animal life appeared in the last 10 minutes, and finally, human civilization, the last tenth of a second in that hour.
The first part of the video concentrated on whales and their ancestors. Whales and dolphin origin is a mystery. They are the few animals that have large complicated brains. Phil Gingerich, a geologist from Michigan University, went to Pakistan and found the back of a skull that resembled a wolf skull, but something was wrong. There was a walnut sized bump inside the skull. Part of the inner ear had a distinctive shape..only found in whales. This formed the question, “did whales come from land mammals?” He needed to find more fossils to show each stage of whale transformation, or their transitional forms. He then traveled to a place where finding whales skeletons seemed highly unlikely: the Sahara Desert. The driest place on Earth but 40 million years ago, it was the southern part of the Mediterranean Sea. There is a 100-mile stretch of sandstone called the Valley of the Whales, filled with rose-colored stones. But these arent stones, theyre 40 million year old whale skeletons. Gingerich believes it once was a protected bay, a lagoon hidden from the open sea by a sand bar, but did they birth young there? Or die there?
Almost all the fossils belonged to the Basilosaurus, an already known whale, but he took them back to his lab to study them anyways. Gingerich then realized something amazing: Basilosaurus had legs, a pelvis, kneecaps, and toes even. Whales had once been 4-legged animals. Their earliest ancestor is a 50 million year old wolf-like animal. It was a predator/scavenger that lived and hunted along the seashore. It probably found the sea rich with food and a haven from competition. Millions of years ago, its front legs could have turned into fins, the rear legs may have disappeared, lost its fur, and formed a streamline shape.
Whales and dolphins swim the same way as otters: undulating their spine, much like how mammals run. Neil Shubin says evolution didnt intend anything new; it was just tinkering with land mammals as it does with every group in history.