AskEssays.com - Discover essay samples

Endangered species of south

4.9 of 5.0 (70 reviews)

Contains
767 words
Category
Science

Endangered species of south page 1
Endangered species of south page 2
Endangered species of south page 3
The above thumbnails are of reduced quality. To view the work in full quality, click download.

Endangered species of south


Endangered Species of South America



Endangered species are plant and animal species that are in danger of extinction, the dying off of all individuals of a species. Over 19,000 plant species and 5000 animal species around the globe are classified as endangered, and many thousands more become extinct each year before biologists can identify them (Microsoft 1). The primary cause of species extinction or endangerment are habitat destruction, commercial exploitation, damage caused by non-native plants and animals introduced into an area, and pollution (1). Of these causes, direct habitat destruction threatens the most species.



A steady rate of extinction is a normal process in the course of evolution, and is called the background rate of extinction (Lampton 14). Species have slowly evolved and disappeared throughout geological time because of climate changes and the inability to adapt to survive competition and predation. Since the 1600's, however, the rate of extinction has accelerated rapidly because of human population growth and resource consumption (17). Today, most of the world's habitats are changing faster than most species can adapt to such changes through evolution, or natural selection. The current global extinction rate is estimated at about 20,000 species per year, exponentially greater than the background extinction rate (17). Many biologists believe that we are in the middle of the greatest mass extinction episode since the disappearance of the dinosaurs 65 million years ago (18).



The survival of ecosystems (plant and animal communities and their physical surroundings) such as forests, coral reefs, or wetlands depend on their biodiversity or variety of plants, animals, and habitats, as well as the many interactions among these species. The removal or disappearance of one or several species may irreversibly damage the ecosystems and lead to its decline. For example, the undersea kelp forest ecosystems of the northern Pacific Rim are some of the richest marine habitats known - they are the home or breeding ground of many species and other wildlife, such as sea otters. When the sea otter population off the western coast of Canada and the U.S. was hunted almost to extinction in the 19th and early 20th centuries, invertebrates such as the sea urchins were left without a major predator. The population of sea urchins increased dramatically and rapidly consumed the kelp and other seaweed, turning the rich ecosystem into a barren undersea terrain (Grolier 41). Conservation efforts throughout the latter half of the 20th century, such as the U.S. Marine Mammal Protection Act (1972), allowed for the protection and reintroduction of the sea otter to these ecosystems and kelp forests once thrived again (41).



The irreversible loss of biodiversity has a serious impact on the ability of remaining species, including humans, to survive. Humans depend on species diversity and healthy ecosystems to provide food, clean air and water, and fertile soil for agriculture. In addition, we benefit greatly from the many medicines and other products that biodiversity provides. As many as 40 percent of our modern pharmaceutical medicines are derived from plants and animals (Fast Facts about Endangered Species 1). A small plant from Madagascar, the rosy periwinkle, produces substances that are effective in fighting two deadly cancers, Hodgkin's disease and Leukemia (Newman 135). Yet the forest habitat of the rosy periwinkle is rapidly disappearing to supply firewood and farmland for the impoverished people of Madagascar, and most of the endemic species there - that is, species that live nowhere else - are endangered.



Species become endangered or extinct for a number of reasons, but the primary cause is the destruction of habitat by human activities. As species evolve, most adapt to a specific habitat or environment that best meets their survival needs. Without this habitat the species may not survive. Pollution, drainage of wetlands, conversion of shrub lands to grazing lands, cutting and clearing of forests, urbanization, coral reef destruction, and road and dam construction have destroyed or seriously damaged available habitats (Microsoft 2). Habitat fragmentation has caused plant and animal species in the remaining islands of habitat to lose contact with other population of their own kind. This reduces their genetic diversity and makes them less adaptable to environmental or climate change (Lampton 21).



Since the 1600's, worldwide commercial exploitation of animals for food and other products has caused many species to become extinct or endangered (Microsoft 2). The whaling industry, in which whales are slaughtered for oil and meat, has led many whale species to the brink of extinction (2). Virtually entire families of plants such as cactus, orchids and cyads are considered threatened or endangered ...

You are currently seeing 50% of this paper.

You're seeing 767 words of 1533.

Keywords: endangered species of south america, endangered species of south africa, endangered species of south carolina, endangered species of southern california, endangered species of south india, endangered species of south florida, endangered species of southern indiana, endangered animals of southeast asia

Similar essays


Biology heat loss practical write up

Biology Coursework Practical ' Heat Loss The aim of this practical is to find to what extent does the surface area to volume ratio of an object affect the rate of heat loss from the object Hypothesis: As the ratio of surface area to volume of an object decreases the rate of heat loss from the object will also decrease. Objects with th...

99 reviews
Download
Extinction of dinos

Could an exploding star have been responsible for the death of the dinosaurs? This idea has become popular again as an explanation for the disappearance of the dinosaurs. An exploding star can blast material enormous distances into space. If this material reached Earth?s atmosphere, changes may have occurred that were harmful to life....

49 reviews
Download
Encephalitis

- ENCEPHALITIS literally means an inflammation of the brain, but it usually refers to brain inflammation caused by a virus. It may also be called ?acute viral encephalitis or aseptic encephalitis?. is an infectious disease of the Central Nervous System characterized by pathologic changes in both the gray and white matter of the sp...

169 reviews
Download
Big Bang

It is always a mystery about how the universe began, whether if and when it will end. Astronomers construct hypotheses called cosmological models that try to find the answer. There are two types of models: and Steady State. However, through many observational evidences, the theory can best explain the creation of the universe...

206 reviews
Download
Hepatitis b 2

Hepatitis B can be prevented with a highly effective vaccine, but this year ten to thirty million people will become infected with the hepatitis B virus. I feel that because this disease is preventable, only knowledge can help reduce the number of people infected. Hepatitis B is a serious liver disease caused by the hepatitis B virus...

110 reviews
Download
Consciousness as determined through the times

Consciousness is understood in a variety of ways. In one belief, a person is conscious when awake, but unconscious when sleeping or comatose. Yet people also do things requiring perception and thought unconsciously even when they are awake. A person can be conscious of their physical surroundings, pain and even a wish or fantasy. In short...

161 reviews
Download
Memory Debate for Psychology

The Memory Debate The debate over the reliability of memory has been going on before psychotherapy even started. I would like to first began by explaining how a human being's memory works, memory is an information process, somewhat like a computer information-processing system. We use encoding, which is getting information into our brai...

114 reviews
Download
From water to land

From Water to Land (Revision) Abstract: The early tetrapods were the first vertebrates to actually walk the solid earth. They began their conquest of land in the Paleozoic era around 360 million years ago. The question many paleontologists have been asking for a long period of time is whether the anatomy for locomotion on land was develope...

18 reviews
Download
Fishes

There are two classes of fishlike creatures in the Chordate Phylum. The first is Chondrichthyes Class, which comprises mainly of Sharks and Rays. The seconds is the common Bony fishes of the class Ostechithyes. The apparent similarities between each speech are only skin deep. They have similar dapperly solely because of convergent evolution and...

19 reviews
Download
Rasmussens Encephalitis

The human immune system is an amazing system that is constantly on the alert protecting us from sicknesses. Thousands of white blood cells travel in our circulatory system destroying all foreign substances that could cause harm to our body or to any of the millions of processes going on inside. Now imagine a condition where thi...

6 reviews
Download
Mosquitoes

Flying Pins are insects belonging to the order Diptera. Only females bite. Female mosquitoes have a long piercing proboscis (mouthpart) they use to extract blood from other animals. After mating with a male, the female needs a meal of blood to keep her developing eggs healthy. Male mosquitoes do not have a proboscis which allows them to...

94 reviews
Download
Nitrate Contamination of Groundwater Poses a Serious Health Threat

Nitrates contamination of the world?s underground water supply poses as a potentially serious health hazard to the human inhabitants on earth. High nitrate levels found in well water has been proven to be the cause for numerous health conditions across the globe. If we intend to provide for the future survival of man, and life...

36 reviews
Download
Aquaria in relation to science

The hobby of fish keeping is much more difficult than it seems. It is also directly dependant on science. The bacterial cycle is one aspect related to science. As is how different filters work. Water conditions such as temperature, ph, and salinity play a big role in successful fish keeping as well. Science and Fish keeping go hand in hand....

102 reviews
Download
Theories of The Origin of the Moon

The Moon is the only natural satellite of Earth. The distance from Earth is about 384,400km with a diameter of 3476km and a mass of 7.35*1022kg. Through history it has had many names: Called Luna by the Romans, Selene and Artemis by the Greeks. And of course, has been known through prehistoric times. It is the second bri...

47 reviews
Download
Atsisiųsti šį darbą