Table of Contents
- 1 What is unusual about whale evolution?
- 2 What is the fossil connection between indohyus and the whale?
- 3 Which piece of evidence supports the hypothesis that cetaceans whales evolved from terrestrial mammals as opposed to some aquatic organisms?
- 4 What did whales dolphins and porpoises evolved from?
- 5 How is the Pakicetus related to whales?
- 6 How did killer whales evolve?
- 7 How can you tell if a whale is an evolutionary ancestor?
- 8 Why don’t baleen whales have teeth?
What is unusual about whale evolution?
Unlike the hippo’s ancestor, whale ancestors moved to the sea and evolved into swimming creatures over a period of about 8 million years. Fossils of gigantic ancient whales called Basilosaurus were first mistaken for dinasaur fossils but were later recognised as mammals.
What is the fossil connection between indohyus and the whale?
But one step was missing: The identity of the land ancestors of whales. Now Thewissen and colleagues have discovered the skeleton of Indohyus, an approximately 48-million-year-old even-toed ungulate from the Kashmir region of India, as the closest known fossil relative of whales.
How do fossils help us understand the evolution of whales?
Fossils are preserved remains of plants and animals that lived thousands to millions of years ago. Fossil remains indicate that whales evolved from hoofed land animals.
Why did the Pakicetus evolve?
It lived on land, on the edge of lakes and riverbanks in what is now Pakistan and India. It hunted small land animals and freshwater fish, and could even hear underwater. Eventually the relatives of this animal ventured further into the water and evolved to cope with their new environment.
Which piece of evidence supports the hypothesis that cetaceans whales evolved from terrestrial mammals as opposed to some aquatic organisms?
What evidence supports the hypothesis that whales evolved from land-dwelling mammals? The femur bone, a vestigial structure, that is still present in whales supports the hypothesis that whales evolved from land-dwelling mammals.
What did whales dolphins and porpoises evolved from?
Cetaceans (whales, dolphins, and porpoises) are an order of mammals that originated about 50 million years ago in the Eocene epoch. Even though all modern cetaceans are obligate aquatic mammals, early cetaceans were amphibious, and their ancestors were terrestrial artiodactyls, similar to small deer.
What are two extinct species that share a close evolutionary relationship with humpback whales?
Mesonychids were not the ancestors of whales, and hippos are now known to be the closest living relatives to whales.
How did scientists use fossils to solve the mystery of whale evolution?
Starting in the late 1970s, a growing number of fossils have allowed scientists to piece together the story of whale evolution. The fossils represent ancient, whale-like animals. They show that an ancient land mammal made its way back to the sea more than 50 million years ago. It became the ancestor of modern whales.
Over time, fossils also revealed that Pakicetus had an ear bone with a feature unique to whales and an ankle bone that linked it to artiodactyls, a large order of even-toed hoofed mammals that includes hippos, pigs, sheep, cows, deer, giraffes, antelopes, and even cetaceans, the only aquatic artiodactyls.
How did killer whales evolve?
Orcas evolved from a small deer-like species that roamed the earth more than 50 million years ago. They are among the most formidable animals in the ocean — pack-hunting creatures that feed on everything from salmon to blue whales.
What is the plot of whale evolution?
Whale Evolution: Call it an unfinished story, but with a plot that’s a grabber. It’s the tale of an ancient land mammal making its way back to the sea, becoming the forerunner of today’s whales.
How did the whale get back to the sea?
It’s the tale of an ancient land mammal making its way back to the sea, becoming the forerunner of today’s whales. In doing so, it lost its legs, and all of its vital systems became adapted to a marine existence — the reverse of what happened millions of years previously, when the first animals crawled out of the sea onto land.
How can you tell if a whale is an evolutionary ancestor?
Another indication of whales’ evolutionary heritage can be seen in the way they move. Credits: © 2001 WGBH Educational Foundation and Clear Blue Sky Productions, Inc. All rights reserved. Call it an unfinished story, but with a plot that’s a grabber.
Why don’t baleen whales have teeth?
Similarly, baleen whales have no need for genes responsible for making teeth, and finding the remnants of such genes would make a strong case for an evolutionary origin of baleen whales as the modified descendants of toothed whale ancestors. Independent Lines of Evidence, but Contradictory Stories?