Pakicetus: The Evolution Of Whales

During whale evolution many skeletal changes occurred, the whale started out as an animal that mostly hunted and existed on land and slowly evolved. The skeletal system of a whale got much longer, its body developed new structures to help increase its survivability such as its flippers.

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.

Some information to get you started is that the scientific name for the Blue Whale is Balaenoptera Musculus, Musculus means “little mouse” which is

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

In marine mammal biology a large portion of the study is dedicated towards the study of adaptations to the marine environment. By comparing the anatomy between marine mammals and terrestrial mammals scientists can better understand evolutionary history of how these two categories of mammals diverged from one another. The purpose of this lab was to study the anatomy of different marine and terrestrial mammals and compare their similarities and differences in homologous traits and how adaptations were made specifically for marine mammals to survive the aquatic environment. To accomplish this bones of different species of animals were studied since these structures serve as the basis for comparison across species as well as an indicator of each animal’s individual morphology and physiology. A standard measurement protocol for bones of particular regions of the skeleton was established with emphasis on length versus width ratio as well as it’s overall size relative to its more complex features, i.e. humerus length versus hand length.

What can have 48-52 teeth or no teeth at all? It is the gorgeous creature we call the whale? From Belugas, to Humpbacks, to Killer Whales, there is much to learn about these lovely gentle giants. Did you know that Beluga whales are the smallest species of whale? Belugas can reach weights of 3,000 pounds, adults are reported to be 14 feet long.

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.

The earliest whales were land animals with long skulls and carnivorous teeth. Analysis of whale skulls showed major morphological changes, including changes to the skull size, shape, teeth, and nostrils. Fossil evidence shows that the trait of interest, the nostrils, can be found on fossils of the earliest whales, dating back to about 50 million years ago. Evolution occurred multiple times since then, each time resulting in the nostrils migrating further back on the skull. Eventually, the pair of nostrils positioned itself right on top of the head. These nostrils are the blowholes we see positioned on top of modern whales today. In addition, another momentous change in the nostrils occur when order Cetacea splits into Mysticetes and Odontocetes. Suborder Mysticetes

The beluga whale is a magnificent creature roaming the seas. Scientifically named delphinapterus leucas, they have five-inch-thick layers of blubber to help them through their journey across the ice. “Belugas, unlike other whales, have teeth” (Defenders of Wildlife). Their pure white color help belugas blend in with the ice to hide from predators. The beluga whales unique habitat, intriguing physical characteristics, bizarre social behaviors, and rare threats make them a peculiar animals in the sea.

Beaked whales, which often have dolphinlike snouts rather than blunt muzzles, typically dive hundreds of meters or more to chase squid, fish, and other prey. But at least one ancestral species in this group of toothed whales, also known as ziphiids, was cruising near-surface waters for its meals, new evidence from newly described fossils suggest. Those remains—the first of any toothed whale to also include fossils of its presumed prey, researchers say—were unearthed along the southwestern coast of Peru last year. The rocks that entombed the partial remains of the whale (Messapicetus gregarius, depicted in an artist’s reconstruction, above) accumulated as sea-floor sediments between 8.9 million and 9.9 million years ago, other fossils in the

Humpback Whales live from the equator to the subpolar latitude because that is where their food is. The whales migrate as far as 16,000 miles which makes them one of the furthest migrating species in the world. Humpback whales migrate on the surface of the water because they are mammals. The humpback whales’ calving grounds are near offshore systems, islands, or continental shores. Humpback whales have a diet that consists of many small fish. They eat small prey such as squid, krill, herring, pollock, haddock, mackerel, capelin, salmon and various amounts of other fish. Humpback whales have two of the methods of catching prey are bubble netting and filter eating. Humpback whales eat more than a ton a day (nmfs.noaa.gov and whalefacts.org).

This research focused on a beluga whale (Delphinapterus leucas) population located in St, Lawrence Estuary that had gone from 5,000 to 500 in number since the start of the century. The question they were trying to answer was; how much do the chlorine containing chemicals (organochlorines) in the environment affect the production, maintenance and repair of body tissue in beluga whales? This research was started because huge amounts of toxins were found in some tissues that had serious lesions in the dead bodies of some beluga whales. This research was conducted in vitro on spleen cells and thymus cells which were intentionally exposed to these chemicals because this where the beluga whales had the most white blood cells to fight of infections and help the cells regain accuracy in their function. The two main factors that were being tested were viability or the potential for the cells to recover from damage and proliferation, the increase in cell number a

Beluga whales, known for their white color, are one of the most popular species of whale as well as one of the most threatened. These relatively small whales, only about 14 feet long, are prey for polar bears, killer whales, and humans who hunt them for blubber and skin. White whales are very unique from other whales in that they have flexible necks to allow them to move their head in all directions, no dorsal fin, and are the only whales with all white skin. Aquariums and organizations all over the world have made in effort in protecting these playful whales. Some of the efforts being made include retreiving injured whales and nursing them back to health, breeding belugas in captivity to be released, and housing belugas deemed unfit to return

Marine biology is the scientific study of aquatic organisms, their characteristics and behaviors [1]. Even though everyone on the planet is aware of the fact that about 70 percent of the Earth’s surface is covered with water, it is believed that only 5 to 10 percent of the oceans have been explored yet [1]. There are hundreds of thousands of marine creatures that can be found underwater with unique features. Ocean life is very diverse and is categorized into different groups, such as sharks, mammals, reptiles etc. Of them, whales fall into the category of mammals and are considered as one of the most magnificent and amazing creatures that have ever lived in the sea. In this essay, I am going to sketch the evolution

In this paper, I will attempt to answer the question: do animal, specifically whales, have a culture? First, I will define what culture means in the scientific world, then a discussion about the viewpoints of Kim Hill and why he does not support