The Polar Bear (Ursus maritimus) is a bear native largely within the Arctic Circle encircling the Arctic Ocean, its surrounding seas and land masses. Although it is closely related to the Brown Bear, it has evolved to occupy a narrower ecological forte, with many body characteristics adapted for cold temperatures, for moving across snow, ice, and open water, and for hunting the seals which make up most of its diet. Though there are many theories surrounding evolution, the two stand outstanding hypotheses applying to the modification from Brown Bear to Polar Bear are Lamarck’s theory of Use and Disuse, and Darwin’s theory of Natural Selection. The intention of this paper is to compare these thesis and determine the most appropriate in relation this event.
According to Lamarck’s theory, features can be strengthened or rid of completely through use or disuse over generations. For example, Jean Baptise Lamarck believed that the giraffe's long neck was an "acquired characteristic". After a lifetime of straining to reach up to eat leaves, a giraffe’s neck would elongate. Baptise thought that the offspring of these giraffes would then be born with longer necks. Lamarck’s theory has widely been disproved, especially with the discovery of heredity genetics. If the theory were correct, a man who works hard to get large muscles, would father naturally strong children. Though the physical side of the idea may be dismissed, many researchers are studying whether behavioural traits can be passed down from a parent to their young.
Charles Darwin’s theory of Natural Selection is the process by which biological traits become either more or less regular in a species and is a key component of evolution. Natural Selection occurs when a subject has a feature that enables to be able to survive more easily than those without it. Take for example the Galapagos Finches (Darwin’s Finches). Found on the Galapagos Islands in the Pacific Ocean are a group of about 13 types of finches...
What is the evolution of a polarbear?
Polarbears have lived in the arctic for many years. Their bodies have adapted and developed in order for their survival in the polar region. Polarbears are able to live in the deep freeze for many reasons. They have thick fur that keeps in their body heat. They have small ears and a small tail which means they lose less heat. Their paws are so big that they act like snowshoes, and the pads on their feet have an anti-slip skin, which would be similar to sandpaper.
For thousands of years polarbears have lived a great life in the North. The Inuit (a tribe) people have lived with them, hunting them occasionally for food or clothing. There was never any fear that the Inuit would over hunt the polarbears because it was dangerous and the weapons available to them were creative. In more recent times, the polarbears have been sought out by hunters, just not the Inuit who live in the North. They have been over hunted by people looking for the big trophy. Eventually in the 1970s the over hunting was brought under control by the International Agreement on the...
Darwin's Evolution by Natural Selection
Darwin's Evolution by Natural Selection
Charles Darwin is known in the science community as one of the pioneers of the theory of evolution. While many people believe that Darwin founded the theory of evolution, he actually didn’t. The theory of evolution actually dates back to the ancient Greeks. Greek philosopher Anaximander actually began the theory of life developing from non-life and the gradual evolution of man from animal. However, Darwin brought something completely new to some of the old evolution theories. That new additive became known as Natural Selection.
Charles Darwin’s education at Cambridge University actually knew him as a God loving man. Firmly believing in creationism and especially the Book of Genesis found in the Bible, Darwin destined to become a clergyman at the Church of England and so decided to earn a degree in Theology. Darwin befriended a professor by the name of John Stevens Henslow while at Cambridge. Henslow introduced Darwin to Captain FitzRoy of the HMS Beagle which was a research ship preparing to set sail on a five year voyage. Darwin was invited to sail aboard the HMS Beagle, which took him along the coasts of South America. While on the Voyage, Darwin entertained himself with a book given to him by Henslow. Sir Charles Lyell, who was a Geologist, and wrote...
...Outline in detail Darwin’s idea of ‘natural selection’, and explain how this differed from previous evolutionary theories.
Charles Darwin (1809-1882) was a British naturalist who is famously associated with the term ‘natural selection’ which he believed was the process that caused species to evolve.
In this essay I aim to explain Darwin’s theory of evolution through natural selection, contrast it with other similar theories set before it and then an overall conclusion.
Darwin originally studied medicine at Edinburgh University but had an interest in natural history where he was influenced by the work and evolutionary theory of French naturalist Jean-Baptiste Lamarck (1744-1829).
In 1831 Darwin joined a five year exploration ship, The Beagle, where he read the ‘Principles of Geology’ (1830), the works of geologist Charles Lyell (1797-1875). Lyell comments on the change in rock sediments and suggests that fossils found in rocks may be proof that animals lived thousands, if not millions of year previously. This influenced the ideas of Darwin greatly.
During the explorations of The Beagle, Darwin discovered several different types of closely related finch species on the Galapagos Islands near South America. Although very similar, they had differing characteristics such as their beaks which he later concluded were adaptations for what food was accessible on specific islands...
The controversial argument between what man has grown up believing and the facts of science would set a landmark in the modern scientific community today. This landmark would be set in history by the English naturalist Charles Robert Darwin and his theory of man’s evolving genes in natural selection. Charles Robert Darwin was born on February 12, 1809 in Shrewsbury, Shropshire, England. He was the fifth child and second son of Robert Darwin and Susannah Wedgwood . Charles Darwin’s father, Dr. Robert Darwin, was a well respected figure in Shrewsbury by both rich and poor. Dr. Robert Darwin was also a member of well-read people with strong Whig leanings. A Whig is a person that belonged to the Wig Party that championed for parliamentary reform . As a young child Charles, in his mind, was not a normal child for he was fond of doing very strange things. Some of these weird things were like the time when he beat a puppy just for the feeling of power. Another one of the strange things that Charles as a child did was that he would collect eggs but only take one egg from a bird nest at a time. The education that Charles received as a child was at first from his sister before going to day school. Unsucceful at school he was removed two years before completion. That summer he spent his time accompanying a doctor on his rounds. Later that year he went with his brother to Edinburgh...
...only traits that the parents were born with. I formed similar thoughts about the finches.
As you may be thinking, my theory is very controversial within the church. Most people think low upon me for believing my theory. Some say Natural Selection is going against the churches belief of the Genesis written in the Bible. Fortunately for you, you are part of the monastery. You have your colleagues to support your ideas and thoughts. I am in the process of writing book to express my ideas to the people. I hope my ideas will be revolutionary and change the thoughts of evolution. My wish is that society will someday find value in my research, even if it is rejected by the church in present.
...become extinct. The polarbear is threatened with extinction because of habitat destruction, hunting, and pollution; however, conservation groups and protection laws are working to save them.
I’m going to tell you a little bit of background about polarbears, where they live, and what they eat. I will also inform you of the main causes for why polarbears are endangered. And lastly, I will talk about the solutions that the government has done and what they plan to do, and also how we can help save the polarbear.
Polarbears are mammals. They are the fourth largest mammal and the largest
land carnivore in the world. The polarbear is the world’s top predator, and it has no predators, except humans. Polarbears have thick white fur and a layer of fat underneath to keep them warm. Adult polarbears can be as tall as 10 feet and weigh between 500 pounds and 1,500 pounds. (here is a fully grown adult male polarbears and it is 10 feet 4 inches) Adult females are usually a little smaller than adult males. Polarbears have huge claws and sharp teeth (like this), which help them kill their prey.
Wild polarbears live only one place in the world, the arctic, which...
...Global Warming has had a great impact on the polarbears To
have a better understanding of how it is having an impact on them we
need to understand the polar bear’s ecological niche. Polarbears are
known to be the biggest carnivore on land. Polarbears have lots of
fur on their body and on their feet, that act as snowshoes. Their
creamy-white fur is dense and water-repellent, enabling them to shake
dry after swimming. Polarbears have many adaptations that help them
survive. They have long curved claws that are sharp to help them cling
to the ice. They also have blubber under their skin which insulates
them from the cold weather. You will find Polarbears in Polar Regions,
these regions include Russia, Norway, Greenland, the United States and
Canada. Most of their time is spent near artic ice floes and when they
are on shore they remain near the water. Polarbears feed mainly on
ringed seals and bearded seals, depending on their location, they also
eat harp and hooded seals and scavenge on carcasses of beluga whales,
walruses, narwhals, and bowhead whales.The
birth potential of polarbears is 1-3 cubs per birth and on very rare
occasions they give birth to 4 cubs. One to two polarbears will...
...Polarbears are the largest land carnivores in the world, rivaled only by the Kodiak brown bears of southwestern Alaska. Polarbears sit at the top of the food chain in the biologically rich Arctic. The most carnivorous of the bear species, polarbears feed primarily on the fat of ice-dependent seals. The remains of these seals provide food for many other Arctic wildlife species, giving polarbears a vital role in their ecosystem.
Polarbears are marine mammals, and spend much of their time on Arctic sea ice. Many adaptations make polarbears uniquely suited to life in icy habitats. Their fur is thicker than any other bears’ and covers even their feet for warmth and traction on ice. A thick layer of blubber beneath their fur provides buoyancy and insulation. The long neck and narrow skull of the polarbear probably aid in streamlining the animal in the water while warming the air that they breathe, and their front feet are large, flat and oar-like, making them excellent swimmers.
Polarbears feed almost exclusively on ringed seals and bearded seals. They are also known to eat walrus, beluga whale and bowhead whale carcasses, birds’ eggs, and (rarely) vegetation. Polar...