Strong evidence indicates that whales and other cetaceans (dolphins and porpoises) are descended from land mammals. This is due to their vestigial hind limbs and anatomical similarities with fossils of certain prehistoric land mammals. These land mammals began spending more time in the water until they adapted to the marine environment and became the cetaceans.
One of the earliest ancestors of cetaceans is Pakicetus. He was a wolf-sized mammal that spent most of his time on land. His fossils were found in Pakistan. He appeared shortly after the death of the dinosaurs around 50 million years ago. At the time the region was hot and dry and there was a scarcity of land animals to hunt. Pakicetus found an abundance of food in the sea, and few predators, because many of the predators that once ruled the seas went extinct at the end of the Mesozoic Era. This would be the start of the evolution of whales.
A few million years later Ambulocetus appears in the fossil record. Its name means "walking whale," because Ambulocetus already showed characteristics of cetaceans. He is believed to have been an ambush predator (much like today's crocodiles) and was well adapted for swimming, moving his tail and hind legs in a vertical motion as modern whales do. His hind legs were elongated, his tail was flatter, and his body was more streamlined. He probably waddled awkwardly on land, much like a seal.
The ancestors of whales, such as Ambulocetus, would become further adapted to living in the ocean. Their tails changed shape to further improve their swimming, eventually developing flukes, and their legs shrank to become fins. An example of further adaptation to the water is Rodhocetus, who appears a few million years later. By his fossils he must have been a good swimmer but would have been handicapped on land due to his shrunken pelvis and hind limbs. Both Dorudon and Basilosauruswere the first true whales, and had vestigial hind limbs that were no longer used for swimming. Eventually these disappeared altogether. Even today, we can still observe tiny vestiges of hind limbs in the skeletons of modern whales.
Modern whales evolved only within the span of 10-15 million years. To some people this seems incredibly fast. But remember that adapting to life at sea does not require the evolution of brand-new features, only the modification of old ones.
Why did mammals return to the ocean in the first place? The most likely explanation is that the extinction of the marine reptiles that used to rule the seas left an open niche which marine mammals could easily occupy. There was plenty of food in the ocean, and it would take only a few modifications to reach it.
Seriously.
Whales weren't invented.
Discovered maybe.
6,000 years ago
1993
6,000
It evolved from Primitive transportation.
orcas
I would never have thought that rabbits had anything to do with whales let alone evolve into them. The only similarity that they share is that they are both mammals.
they evolve threw a PERIOD of time
No. Whales did not evolve until about 10-15 million years after the dinosaurs died out.
Bacteria
because blubber
No whales dont think about objects that way, but do the harpoon divers know what the whales will do when they evolve enough to have the ability to hold weapons?
Prehistoric even-toed ungulates (or artiodactyls)
There is very little relation between sharks and whales. Sharks are an ancient primitive creature, and the whale is a modern creature who gives live birth and nurses its young. the whale is a creature which originally lived on land, then adapted to live in the ocean.
Art did not necessarily evolve in a linear progression from primitive to realistic
mammals evolved fat, lost tails, legs turned into fins etc.