It is crucial to note that the extinction of species and populations as a result of unconstraint processes is natural. For thousands of years of geological time, the extinction of some species has been balanced by the emergence of the new ones. Similarly, the loss of the local population (for instance, because of the settlement) has been compensated by the formation of another population.
However, human activity has greatly contributed to an increase in the extinction rate and has put many species and populations under threat of premature disappearance (Burns 18). In XX century, people caused the extinction of hundreds of known vertebrates as well as invertebrates. Needless to say that the premature extinction of species has serious consequences for the environment and biodiversity. In order to understand the major causes and consequences of this process, it is necessary to analyze the different aspects of it.
Biodiversity
Biodiversity is the totality of all life forms inhabiting the planet. It is the richness of life and its processes including a multiplicity of living organisms and their genetic differences as well as a variety of places of their existence. Biodiversity can be divided into three hierarchical categories: diversity among the same species (genetic diversity), diversity between species, and between ecosystems (Swanson 31).
It is important that premature extinction inevitably affects all three forms. The greatest diversity of species is typical for (in descending order): humid equatorial forests, coral reefs, tropical dry forests, moist forests of the temperate zone, oceanic islands, Mediterranean climate landscapes, and treeless (savanna, steppe) landscapes (Swanson 31). In the past two decades, the issue of biodiversity has become increasingly important not only for specialists in biology but also for economists, politicians, and the public due to the apparent threat of anthropogenic degradation of it, which is now much higher than the natural degradation.
Several aspects should be considered in terms of consequences of the premature extinction to the biodiversity. Many of the most crucial properties of biological diversity are manifested in natural environments exclusively. For instance, there is a co-evolutionary and ecological relationship between tropical flowers, hummingbirds, and flower mites; the latter use hummingbird beaks to move from flower to flower (Gaston and Spicer 94). Such links would have never been formed if the plants and animals lived in isolation in zoos and botanical gardens.
Similarly, uncommon behaviors of desert animals that they apply when searching for water would not have arisen in animals that have sufficient amounts of water supplies. It should be noted that even if a considerable part of the diversity of flowering plants and vertebrate animals were secured in zoos and gardens, the diversity would still lose its ecological relationships characteristic of natural communities. It is the main argument that should encourage keeping all the biological communities safe.
Further, the evolutionary adaptation is under threat. It’s a process that ultimately leads to the emergence of new species and increases biodiversity (Swanson 39). Therefore, it is necessary to provide the opportunity for populations to develop in vivo. Human actions that stifle the evolution of populations, for example, due to a strong reduction in the number of a particular species or the destruction of unique populations, are destructive.
Causes of Premature Extinction
According to various sources, at present, more than thirty thousand species of animals and plants are under the threat of extinction. Over the past 400 years, more than 484 animal species and 654 plant species have disappeared (Schneider 55). The reasons for the accelerated decline in biological diversity include a number of circumstances. For instance, the rapid population growth and economic development force a huge change in the conditions of life of all organisms and ecological systems of the Earth.
The increasing migration of people, the growth of international trade and tourism, and the settings for these processes also adversely affect biodiversity. One of the major reasons is the increasing pollution of natural water, soil, and air as a consequence of human activity as well (Schneider 55). In addition, the lack of attention to the long-term consequences of actions that destroy the conditions for the existence of living organisms that exploit natural resources as well as the introduced non-native species also contribute to decreasing in biological diversity and premature extinction. The impossibility to assess the true value of biodiversity in the market economy implies a careless attitude towards the environment.
Over the past 400 years, the direct causes for the disappearance of animal species were the introduction of new species accompanied by the expulsion or extermination of the local ones; the destruction of the natural habitats, and the direct removal of the territories inhabited by animals; and the uncontrolled hunting. Scientists have concluded that many species of plants, animals, birds, and insects disappear a thousand times faster compared to natural rates. It means that the planet loses from 10 to 130 species every day (Schneider 101).
At present, over 40% of all living species are under the threat of extinction. If this rate continues to grow or accelerate, the number of endangered species will amount to millions in the next decade. The disappearance of certain species will inevitably lead to global environmental problems threatening the stability of the entire ecosystem of the Earth.
Endangered Species and Causes for Their Possible Extinction
At present, there are many species and animals, birds, and plants, which are under the threat of premature extinction. For example, Sumatran Orangutan is threatened by the loss of habitat due to excessive logging of forests and territory conversion for agriculture and road construction (Barr 43). Despite the creation of national parks, forests are being cut down illegally. In addition, poaching and catching of the cubs with a view to reselling them put this species in danger. Over the past 75 years, the number of orangutans living in Sumatra has decreased by over 80%, and it continues to decline steadily.
Further, Iberian Lynx is mentioned in the category of animals that are in critical condition. According to researches, there are approximately 200 Iberian Lynxes left (Barr 47). Despite the fact that about 35 million USD have been allocated for the salvation of these wild cats, the situation related to their population is critical. The complexity of the issue is that among these 200 species that live in the wild only 22-32 females are ready to breed (Barr 43). Apart from that, White Rhinos are also ultimately endangered. In the wild, adult rhinos practically have no enemies other than humans.
The main threat to all rhinoceros species is poaching. Its horn is a precious good on the black market as it is used for decorative and medical purposes. On the black market, the cost for rhino horns is up to thirty thousand USD. Further, Whale Shark is also in great danger (Rice 19). Despite the ban on fishing, the mining for sharks in South-East Asia and India continues. The peculiarity of whale sharks is their long puberty and slow rate of reproduction, which makes the rapid recovery of the population impossible. Every year the number of whale sharks in the world is reduced by 5%.
Sifaka is a class of endangered lemurs. The loss of habitat due to active logging and burning of forests in the region and the ongoing hunt for lemurs are the main threats to the existence of this genus. Also, the number of Wild Bactrian camels has decreased to a thousand individuals for a variety of reasons. Firstly, they are hunted; secondly, people shoo them during construction works; and thirdly, they are bred with domestic camels, which implies that the offspring become infertile. The Siberian Tiger also relates to the animal species in danger of premature extinction. Tiger bone is highly valued on the black market. At present, the number of tigers living in the wild is estimated at 431 – 529 individuals (Burns 119). The illegal large-scale logging and forest fires deprive tigers of their usual habitat.
Further, Leatherback Turtle feeds on jellyfish, and it is able to dive for them at incredible depth. However, they often get confused and swallow plastic bags thrown by people, for that reason many members of this species die (Rice 21). Moreover, Western Gorillas were classified as endangered in 2007. Poaching, commercial logging, and climate change continue to violate the ecological balance of the environment and lead to the gradual disappearance of their populations.
Also, nowadays Giant Panda can only be found only in some mountain ranges in central China, mainly in Sichuan province, and to a lesser extent in the provinces of Shaanxi and Gansu. Due to human activity and deforestation, Giant Pandas have been driven out of the lowland areas where they used to live. Since ancient times Giant Panda has been the target of poaching not only by the local residents who hunted them for soft skin but also by foreigners (Burns 201). The population of Giant Panda annually inexorably declines due to the extremely low birth rate both in the wild and in captivity. Scientists estimated that there were less than 1600 individuals left. Thus, judging by the described cases, the main causes of species premature extinction are reduced largely to human activity.
Conclusion
The destruction and reduction of species habitat leading to the fragmentation of species populations or their displacement are the main causes of species extinction. Other causes are related to the direct or unintentional destruction of natural habitats due to human activity. These reasons have led to the disappearance or resulted in critical population sizes, the possibility of survival of which raises serious concerns.
It is obvious that for predicting the fate of any species whose population quantity falls, it is necessary to investigate both the natural and anthropogenic factors that affect their condition. These way special measures can be thought through and implemented to change the situation for the better. It is essential to raise awareness of people and implement practices aimed at preserving all the species to ensure that the biodiversity will be maintained.
Works Cited
Barr, Nevada. Endangered Species, New York: Hachette, 2013. Print.
Burns, Rex. Endangered Species, London: Head of Zeus, 2014. Print.
Gaston, Kevin, and John Spicer. Biodiversity, Hoboken: John Wiley & Sons, 2013. Print.
Rice, William. Endangered Animals of the Sea, Huntington Beach: Teacher Created Materials, 2013. Print.
Schneider, Jacqueline. Sold into Extinction, Santa Barbara: ABC-CLIO, 2012. Print.
Swanson, Timothy. Global Action for Biodiversity, New York: Routledge, 2013. Print.