Bibliographic Information: Smithsonian. "Whales only recently evolved into giants when changing ice, oceans concentrated prey: Analysis of fossil, modern whale’s points to when and how whales started bulking up." ScienceDaily. ScienceDaily, 24 May 2017. . Introduction: After analyzing the fossils or preserved remains of whales, scientist have determined that whales have only recently evolved to be the large animals that we know today. Though not sure, the scientist state that the evolutionary shift was due to the increase of ice sheets in the North. This increase in ice caused a shift in the concentration of food available in the ocean, increasing the benefits of having a bigger body. This is important to the scientific community because …show more content…
The shift in whale size occurred during the beginning of the Ice Age and the increase in ice sheets may have caused a change in the distribution of food. Before the ice sheets, food would have been evenly distributed; however, as the ice sheets formed, run off would’ve increased the amount of food like krill and plankton in the water, this increase along with the filter-feeding mechanism of the baleen whale would have given the advantage to larger whale, who would have been able to utilize the dense aggregations of prey in the water.
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A. This study mainly focuses within Big Idea 1, the process of evolution drives the diversity and unity of life. Within the study, the scientists observed how organism are linked by a common ancestry (1.B) through cladograms and the width of the skull from fossil records. With these fossils, the scientists observed the shift of size in the whale’s bodies and how organisms from a common ancestor change and differentiate in structure over time. This allowed for them to see what traits were gained and lost, causing not only speciation in the organisms but also overall phenotypic changes. Similarly, in this study, the scientists were able to unveil how life continues to evolve with a changing environment. Extinctions and speciation occur all the time due to the environment. Though it’s not proven, the phenotypic shift within
In the article, “Sperm Whales and Killer Whales with the Largest Brain of All Toothed Whales Show Extreme Differences in Cerebellum” the author Sam H. Ridgway studies the cerebellums of the most widest distributed whales in the world. The killer whale and the sperm whale both have huge brains, but this study suggests why the killer whales have a significantly larger cerebellum than that of the sperm whale. After collecting, measuring, and preserving the species, the skull was ready to be chipped away and the brain ready to be taken from the massive cranium. Once extracted, the brain was measured to determine the cerebellar volume: (length of cerebellum base × width of the base × height × 1/3).
The study was first embarked in an attempt to assess what could be done to help the depleting population of the wester Pacific whale. However, it later turned up evidence that may imply that western Pacific whales may just be California gray whales with different swimming patterns.
The research showed that whales contribute important nutrients and they are heart on marine food chain. Lead researcher Trish Lavery from Flinders University explained that Whales' poo actually provides a source of important nutrients for fisheries (2014). It has been positive impacts on the ocean that whales feed sea-life by their poo and it saves sea life’s population growth. It shows why whales’ poo is crucial for the marine food chain. Moreover, the researchers mentioned that past global declines in marine ecosystems occurred about the same time as the number of whales’ population were decreasing. (Boness, 2014). The scientists indicated that when whales feed, then they return to the surface for breathing and they mix up the water. It has advantages by spreading nutrients and through the marine zones; they can lead to saving sea life (Howard, National Geographic,
Secondly, the author indicates that humpback whales moving for long distance and staying on track by relying on stars. The lecturer, on the other hand, suggests that there may be other external forces like magnetic field. Evenmore,
By calculating the amount of food lost because of dropping sea levels, and combing this with estimates of the food needed to keep a whale alive, Lindberg and Pysenson calculated the impact of global cooling on gray whale populations and the populations that would have had to exist in order for the whales to survive. They then concluded that populations would have had to have alternative feeding modes sufficient to support a population of around 70,000 during warm periods so that population drops during glacial periods wouldn't be below 5,000 to 10,000 whales. Much lower numbers would have produced a genetic bottleneck obvious in the DNA of the whales and Lindberg stated "such a signature has not been
The characteristic that we are focusing on are the teeth development in the Narwhals and Beluga whales. The growth of teeth in the two whales are different. “The Beluga whales have eight to ten
When final month of the whaling season in the year of 1897, captains of eight whaleships from San Francisco were fishing in the Arctic Ocean off the coast of Alaska. They thought they had a few more weeks of good weather to continue whaling (hunting whales for needs) before heading south. Yet suddenly during the first week of September, the temperatures fell dramatically and soon, heavy ice was coming in from far out to sea. The ships were forced to lay anchor to wait for favorable winds to drive the ice away as it was stated when the whales got stuck in the wharsh weather. But when the warmer winds came, the ice didn’t melt, and the ships were trapped.
The blue whale uses baleen in order to filter the speech. The blue wales are the largest vertebrate animal. In a study that was reported on May 24 in Proceedings of the Royal Society B, Nicholas Pyenson, the museum's curator of fossil marine mammals, and collaborators Graham Slater at the University of Chicago and Jeremy Goldbogen at Stanford University, went back and found the evolution of the size of whales in over thirty million years of history. They discovered that the huge whales showed up along multiple branches in the family tree roughly two to three million years ago. A reason for whales having those bigger body sizes is that by the increase of ice sheets located in Northern Hemisphere, whales had to change the way they ontaimed food
Whales have roamed the Earth’s oceans for about 50 million years, they are the largest mammals on the planet, ranging from sizes of 8 feet to 112 feet. There are 86 different species of whale, however they are divided into two groups, the Odontocetes, or toothed whales and the Mysticetes, or baleen whales. Out of the 86 different types of whale, the largest is the blue whale, belonging to the mysticetes family. The largest Blue Whale ever recorded was 111 feet in length and about 173 metric tons, not only is it the biggest whale in the world, it is the biggest animal ever known to have lived.
The humpback whale is one of the largest mammals on the planet. Growing up to 18 meters in length, and weighing between 25 to 50 tonnes they are truly behemoths. The humpback belongs to a group of whales called “baleen” whales. Baleen is a thick bristle like growth that extends from the upper jaw of the whale, such whales do not grow teeth which makes then fairly uncommon among carnivores. The whales spend their summers feeding in the cold southern ocean and migrate north to the south pacific during the winter months.
The reading contends that humpback whales migrate long distances by means of their ability to navigate their ways with the help of stars.The lecturer, however, casts doubt on the claims made by the article and provides some evidence to refute them all.
Me and my crew here on the waves of the Antarctic sea have not seen nor tracked any signs of a blue whale since our scientific equipment became operational two weeks ago. The blue whale, the largest animal on planet Earth, has been labeled as endangered on the conservation status chart for more than fifty years and has yet to change. Ever since the banning of blue whale hunting in 1966, blue whales have not increased in population at the rate we have predicted. To this day, even with all the limits hunters have on the ocean, blue whales struggle with accidental beaching and ship collisions.
It is evident that whaling practices can lead to a reduction in the population of whales, ecosystem degradation, and even cause the species to the brink of extinction (International Whaling Commission, n.d.). The main factors causing the problem are over-exploitation, disturbance from whaling vessels, entanglement in fishing gears, and environmental factors (International Whaling Commission, n.d.). According to the WDC (n.d.), more than 36,700 whales were killed after the 1986 moratorium in which Japan accounted for nearly 20,000 whales. The International Whaling Commission (n.d.) reported that the common whales hunted by Japanese, which are Minke, Fin, Sei, Sperm, Bryde’s and Humpback whales, were severely exploited and depleting in terms of population in the Japanese whaling grounds before the 1986 moratorium. In addition, the operation of whaling fleets apparently causing noise pollution affecting the communication process of whales and other marine species as well (Lian & Lu, n.d.). Whales are one of the top-level animals in the marine food chain, therefore, a decline in whale population definitely have an impact on the marine ecosystem. Lian and Lu (n.d.), have said that whale’s dead body is a great source of food for the marine animals in a lower depth of the ocean. Thus, the more whales killed by whaling practices, the less food for others sea creatures and organisms (Lian & Lu, n.d.). Also, nutrients in
Did you even know whales ever lived on land? The whales are the biggest animals. They are larger than the largest dinosaurs. They live in the ocean like other sea creatures, but they almost look like the land-living animals more than the fishes. Furthermore, some scientists believed that around fifty millions of years ago, the whales probably lived upon the land. There are two significant exhibits from the two different periods why the scientists astonish about whale's living is familiar to land-living mammals, which are whale's anatomy in this current period and whale's fossil remains of the past.
Whales have been around on Earth for many years. One thing that originated due to the population of the speices is whaling. Whaling is the act of hunting for whales whether in the need for food, for scientific research, or for commercial reasons. It was not until the 1920’s when the concern for the decrease in whale population was brought to light by the Director of the British Museum, Sidney Harmer (Hoare, 2014). The sudden awareness for the number of whales brought on the “Save the Whales” title, which was used in 1924. By 1930, the League of Nations started to focus on the problem at hand. The focus that was put on the whaling population, brought on many organizations that tried to assist in the regrowth of the whale species.