If the erector pili are activated, the hairs that come out of the nearby follicles stand up and give an animal a larger appearance that might scare off potential enemies and a coat that is thicker and warmer. # 8 Erector Pili and Body Hair The erector pili are smooth muscle fibers that give humans’ goose bumps.It was reported recently that whales and hippos were distantly related. Most of these examples are of whales that had only leg bones, but there were some that included feet with complete digits. There are many cases where whales have been found with rudimentary hind limbs in the wild, and have been found in baleen whales, humpback whales, and in many specimens of sperm whales.
Despite the apparent uselessness, evolution left traces of hind legs behind, and these vestigial limbs can still be seen in the modern whale. Biologists estimate that this happened about 50 million years ago, and that this mammal was the ancestor of the modern whale. Once the land-dwelling creatures evolved, there were some mammals that moved back into the water. At some point these ?fish? began to develop hips and legs and eventually were able to walk out of the water, giving the earth its first land lovers. # 9 Hind Leg Bones in Whales Biologists believe that for 100 million years the only vertebrates on Earth were water-dwelling creatures, with no arms or legs.The wings are not completely useless, as they are used for balance during running and in flagging down the honeys during courtship displays They are, anatomically, rudimentary wings, but they could never give these bulky birds flight. #10 The Wings on Flightless Birds In general, wings of a bird are considered complex structures that are specifically adapted for flight and those belonging to these flightless birds are no different.COMPARATIVE ANATOMY: Vestigial Structures TOP 10 VESTIGIAL SRUCTURES OF ALL TIME !.COMPARATIVE ANATOMY: Vestigial Structures Human Wisdom Teeth ARE Vestigial.COMPARATIVE ANATOMY: Homologous Structures.HOMOLOGOUS STRUCTURES: Bones in the forelimb of the human, whale, cat, bat, bird, alligator are used for vastly different movement, they all have remarkably similar structure and organization (bones, nerves, blood vessels This indicated common ancestry (DNA) Organs with similar structure but different functions are called HOMOLOGOUS STRUCTURES EVIDENCE FOR EVOLUTION: COMPARATIVE ANATOMY By comparing the anatomy of different animals much can be learned about their evolution.
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