Our subject describes the evolution and adaptation of the whales, as we already know the whales change with time and some of their characteristics adapted depending of their habitat. This create new species and this continue to evolved. Now we are going to see the features and descriptions about whales evolution.
Whales are large, intelligent, aquatic mammals. They breathe air through blowholes into lungs (unlike fish who breathe using gills). Whales have sleek, streamlined bodies that move easily through the water. They are the only mammals, other than manatees that live their entire lives in the water, and the only mammals that have adapted to life in the open oceans.
Primitive whales evolved during the mid-Eocene period, about 50 million years ago. Fossils remains indicate that whales evolved from hoofed land mammals - perhaps the shore-dwelling, hyena-like Mesonychid that returned, bit by bit, to the sea roughly 50 million years ago.
Another possible step in whale ancestry is the otter-like Ambulocetus, an extinct mammal the size of a sea lion, 10 feet (3 m) long and about 650 pounds. Its limbs allowed it to swim and could also support it on land. It had long, powerful jaws with shark-like teeth, a small brains, and a pelvis fused to its backbone (like land-dwelling mammals but unlike whales).
Basilosaurus, a very primitive, extinct whale, had a tiny head and pointed snout with teeth, unlike modern-day whales which have large heads and a blunter snout. It was about 82 feet (25 m) long.