Evolution Of Whales

The ancestors of the whales transitioned from being land bearing animals to becoming animals that live in the ocean. While the original ancestor of whales lived on land as it evolved it was able to start to enter the water until it struggled more to get on land than to get in water until the whale’s ancestors began to live exclusively underwater.

The evolutionary path of a whale is a fascinating process of a terrestrial mammal that evolves into a marine mammal. This evolutionary path started with one of the earliest ancestors called “Pakicetus”. A Pakicetus was discovered to be a land animal with four legs that had teeth as carnivores. It skull structure was long, but this organism didn’t look like any marine animal. The scientist then discovered that on the skull’s ear region it was surrounded by a bony wall. This feature on an organism only was distinct from one type of species, scientist discovered that this animal “Pakicetus” was an ancestor of a whale. By comparing the early whales Pakicetus to the next generation of ancestors Ambulocetus, the Ambulocetus whale looks more like

The origin of modern day whales, a mystery that has puzzled paleontologists for years, may have just been solved with the discovery of an ankle bone. This discovery might sound simple and unimportant, but the bones of these ancient animals hold many unanswered questions and provide solid proof of origin and behavior. The relationship between whales and other animals has proven to be difficult because whales are warm-blooded, like humans, yet they live in the sea. The fact that they are warm-blooded suggests that they are related to some type of land animal. However, the questions of exactly which animal, and how whales evolved from land to water, have remained unanswered until now.

The dorsal fin is triangular, and has been know to grow in excess of 6 feet in length on males, but grow no more than 3 feet on females. (Martin) The pectoral fins of the orca can measure up to one sixth of it’s body length and is in the shape of a paddle. The orca usually have 40-50 conical teeth which measure over 2 inches in length, and has a perfect fit with the opposite set which makes it an excellent hunter. Although the teeth are robust, they do a lot of work through the years because older orcas have been known to have teeth worn down to the gum tissue (Haley.) The tongue of a killer whale has been known to weigh in excess of 2 tons (Martin.) They have been known to be fearless hunter, and a fast predator. Some say the ferocity of the killer whale exceeds that of the great white shark, which makes it one of the most feared in ocean life.

Recent evidence suggests that whales may not have always inhabited the oceans. Bones of an ancient ancestor of modern day whales, the Basilosaurus, were discovered in Pakistan that suggest whales evolved from a wolf-like creature. This genus of an early whale lived 34-40 million years ago in the late Eocene. These fossils show many different features in common with both modern day whales and modern day land mammals. Since the discovery of these bones, many other evidences show that whales are a likely descendant of the Basilosaurus through many different ways, such as embryologic comparison and DNA testing. Whales aren’t the only suspected descendants

Whales have a different part of the brain than we do to process emotions. So we never know

On average a killer whale in the ocean lives 60 - 70 years a maximum would be 80 - over 100 years. In captivity a female killer whale live to be about 29 years while a male killer whale lives to be about 17. The year gap between wild and captive orcas is so big because the orcas are too large to live in a 50 ft. deep tank. The most appalling fact to know is that the killer whales are the most prone to diseases in captivity, so they will die sooner than the life expectancy if a disease is caught such as broken teeth. Broken teeth occurs often in captivity. Killer whales are consistently getting treated for dental issues but the effects are unsuccessful. Fractured teeth are caused by biting on the steel gates, the killer whales only bite on the gates for one reason in particular that is wanting to be freed back to the ocean home they belong

Whales are large aquatic mammals. Like every other animal they did not start off like that. Whales came to be after millions of years of evolution. Every aspect of the current whale was decided by nature. The blowhole, dorsal fins, lack of teeth and tail fluke all came from years of other creatures such as the Mesonychids and many other animals.

Whales in captivity suffer through a great amount of emotional abuse . In captivity, Children can be separated from their mothers, and whales that are taken from the wild are separated from their families ,which can consist of up to 40 members (National Geographic). Whales are very family oriented and each pod of whales has their own dialect when communicating. Whales are social creatures and by depriving them of social activity and their families, they become depressed and

Killer whales, also known as Orcas, are very vocal animals and spend their time partaking in clicks, whistles, and pulsed calls. These giants can be found in nearly all oceans due to their migration patterns. Orcas have an unmistakable black and white patterning, making them easier to identify. The Orca is an apex predator, meaning that they are at the top of their food chain. They have been known to feast upon sea birds, squid, octopus, sea turtles, sharks, rays, and fish.

The ocean is a vast biome that is constantly changing. There is much to learn about the life within, the article “Omura's whales (Balaenoptera omurai) off northwest Madagascar: ecology, Behavior and conservation needs” showed how our knowledge of the ocean and the life within continues to grow. Balaenoptera omurai, or Omura's whale was only found as a new species in the year 2003. Their are no dependable population size estimates or evaluation of conservation facts because there is not enough data collected on these cetaceans. Scientists are able apply what they learn from some of these organism to humans. In the article “Reproductive Conflict and the Evolution of Menopause in Killer Whales” scientists were able to draw comparisons between Humans and other species.

Over 420 whale deaths in recent years, the majority of which were calves, suggests that this population and its ecosystem may be less healthy and robust than previously thought ( Fretwell 2014). When the right whale reproduces they tend to swim to coastal waters where they might get hurt and this increase the mortality rate and the fertilization rate. This means that newborn calves are getting killed in coastal waters, but it is a small percentage. Therefore, when these whales grow, they will move to further in the ocean where the can live until the age of 100

In terms of social structure, baleen whales are known to be quite solitary in nature often traveling alone or in small groups.Communication among baleen whales involves loud low-pitched moans and whines, and physical gestures such as spy hopping, lob tailing, breaching and charging.

They move by swinging their tails. Though they are heavy , they move quickly. In winter , they will swim from the Arctic Ocean to the South Pacific . In South worm sea area, whale mother gives birth to whale baby. Then in summer, they will return their home.

Orca Whales (originally called “Killer Whales” by Spanish whalers) are classified as part of the Cetacean group of mammals and are the largest of the dolphin family. Females live an average of 50 to 60 years, males an average of 30 to 50 years, although they have been known to live 70 to 100 years in the wild. Although there are whales in captivity living as old as 30 years, the average in captivity is 20 years. This is the average age of surviving whales in captivity. A new paper published in the Journal of Marine Mammal Science found that although captive orca life spans have improved since the 1960’s when they were first put into captivity, their longevity is statistically poor in comparison to wild whales. “The median survival rate for orca whales in US parks was 12 years” (Jett & Venture, 2015, p. 1362).