Evolution of Whales Animation
Evolution of Whales
Pakicetus, 48 million years ago
[Animated video of a dog-like animal trotting on four legs on land next to a stream with trees and ferns alongside it.]
Foraged in streams. 1.75 meters or 6 feet long.
[An arrow appears, pointing to the animal's nose.]
Nostrils far forward.
[A yellow rectangle appears around the animal's front legs.]
Forelimbs function for walking.
[The yellow rectangle moves to the hind legs.]
Hind limbs function for walking.
[An arrow points to its tail.]
No tail flukes.
Pakicetus continues walking along the stream. The landscape transforms into rolling grasslands next to a river, and the animal's body becomes longer and its head larger and more triangular, like an alligator's. The time period changes to 47 million years ago, and the name at the top of screen is now Ambulocetus.
[The Ambulocetus walks next to the water.]
Alligator-like, fed in the water, 4.15 meters or 14 feet long.
[A yellow rectangle appears around the animal's front legs.]
Forelimbs function for walking.
[The yellow rectangle moves to the hind legs.]
Hind limbs function for walking.
[An arrow points to its tail.]
No tail flukes.
[Ambulocetus continues walking along the river. The time period changes to 46 million years ago, the landscape changes to a cross-section of a body of water with a beach visible across the surface in the distance, and the seabed visible below. The animal transforms, its forelimbs shrinking and pulling in close to its body, its hind limbs angling backward, and its head becoming thin and streamlined. The name at the top of the screen is now Maiacetus.
The animal is swimming underwater, powered by its hind legs which now have large, webbed feet.]
Sea lion-like, spent some time on land. 3 meters or 10 feet long.
[A yellow rectangle appears around the animal's front limbs, which are short, shorter than the hind limbs.]
Forelimbs function for walking and swimming.
[The yellow rectangle moves to the hind limbs. The feet are webbed and are very long, longer than the rest of the limb.]
Large hind limbs.
[An arrow points to its tail.]
No tail flukes.
[The time period changes to 37 million years ago. The landscape changes to show an underwater scene of blue water and a seabed. The name at the top of screen is now Dorudon. The animal has changed to one with a longer body with the forelimbs farther forward and a fluked tail. The Dorudon is swimming by moving its tail and forelimbs.]
Completely aquatic. 4.5 meters or 15 feet long.
[A yellow rectangle appears around the animal's head, with an arrow pointing to the nostrils atop the head.]
Nostrils farther back on skull.
[The yellow rectangle moves to the forelimbs.]
Forelimbs become flippers.
[The yellow rectangle moves down the body.]
Elongation of the trunk.
[The yellow rectangle moves to the hind limbs, which are tiny.]
Reduced hind limbs.
[The yellow rectangle moves to its tail.]
Evolution of tail flukes.
[The Dorudon continues swimming and then stops. The time period changes to 34 million years ago. The name at top of screen changes to Llanocetus. The animal changes to one with a dorsal fin and larger front flippers.]
Completely aquatic. 9 to 10 meters or 30 to 33 feet long.
[An arrow points to the animal's mouth.]
Teeth reduced. First evidence of baleen for filter feeding.
[An arrow points to the nostrils on its head.]
Nostrils far back on skull.
[A yellow rectangle appears around the forelimbs.]
Elbows immobile.
[The Llanocetus swims offscreen to the right. The video goes black. Then the first animal, Pakicetus, appears.]
From land to water, whales evolved rapidly in response to a changing environment.
[The Pakicetus changes into the Ambulocetus, then the Maiacetus, the Dorudon, and the Llanocetus.
The view changes to a video from behind the tail of a large whale.]
Today's whales all spring from one common ancestor ... one that walked on land.
[Screen goes black. Then credits appear.]
3-D Animation: David So, Bobomotion
2-D Animation: Joey Korenman
Scientific Illustration: Diana Marques; Mary Parrish, Smithsonian Institution; John Klausmeyer, University of Michigan
Stock Footage: Feodor Pitcairn Productions, Ltd.
Scientific Advisor: Dr. Mark Uhen
End.
