Major Extinction Events and Biodiversity
MAJOR EXTINCTION EVENTS AND BIODIVERSITY 1
The most critical problem that the environment is the loss ofbiodiversity. Evidence shows that the extinction rates are very high. Many extinctions are recorded both in prehistory and history times.Research indicates that the primary cause of loss of biodiversity isthe human actions which destroy the environment habitat of species.If these human acts are not controlled, it is evident that in futurethere will be a severe crisis in the environment that will take yearsto reverse. In this paper I will highlight the major events that haveled to extinction of various species in the ecosystem andbiodiversity, highlight the Words of Edward O. Wilson, the importanceof the given words and possibly suggest some workable solutionstowards the problem.
Extinction and Radiation Pattern
Through a process called radiation, organisms change from one form toanother. The change occurs when there is an alteration in theenvironment. Variations in the environment avail new resources aswell as create challenges .these changes result in the development ofnew species that have different traits from their ancestors.Radiation occurs whenever there is extinction. For example, when thedinosaurs became extinct, the mammals increased to occupy theecological niche that was being occupied by the dinosaurs.[ CITATION Dav12 l 1033 ]This shows an existence of an association of higher taxon rising anda reverse reaction which is a fall in another higher taxon species.
Two theories have been developed to try and explain the pattern ofthe occurrence of extinction and radiation. These are competitivedisplacement theory and independent displacement theory. Incompetitive displacement theory, the species compete with oneanother, and the defeated species become extinct which leads to therise of the other. On the other hand, independent displacement theoryargues that a group of species only radiate after the other hasdeclined due to some reasons that relate to the environmental change.The competition displacement shows that there is an influence ofcompetition in the extinction and radiation of a higher taxon sinceone group declines in proportion to the other group radiation[ CITATION Eli14 l 1033 ].However, the independent displacement theory shows no competition asone species become extinct before the other species radiate. Anexample to illustrate extinction and radiation pattern is a diversitychange of the group of brachiopods that was drawn by Gould andCalloway. In this model, during the Paleozoic, the brachiopods werevery dominant to bivalve mollusks. During Permian, bivalve did notsuffer as the brachiopods as mass extinction happened. After the massextinction, the bivalves expanded at a high rate after thebrachiopods had declined.
In extinction and radiation pattern, the reason that lead to onehigher taxon replacing the other is explained the competitivedisplacement which has been regarded as the better hypothesis thanthe independent theory although it lacks evidence. Radiation oftenoccurs after one group has gone extinct that’s when a new group ofspecies emerges to occupy the empty ecological niche.
Considering the Words of Edward O. Wilson
Edward O. Wilson when raising this concern was much concerned withthe distraction in the biodiversity. He is known to be raisingawareness about the unending extermination of biodiversity. It shouldbe clear to everybody that extinction of species means a magnitude ofa problem. To understand this one should have an understanding ofwhat biosphere means, the importance of our survival and the greatthreats that are posed to it by the human action. Animals, plants,and man rely greatly on each other man depend on various plants forfood and medicinal purpose. Referring to Hannah,( 2012) thedestruction of these biodiversity means a great harm to man animalsand plants since they exist in a dependence relationship.
Human actions that pose a threat to the biodiversity are, pollutiondestruction of habitats human overpopulation, overhunting andoverfishing. Human should realize that it is not too late to stop theextinction of species and destruction of the ecosystem. Humans,therefore, should embark on safeguarding ant trying to restore thehabitats. Human should not be driven by his lust for expansion andnatural resources but should consider the life that the futuregeneration would be living with a destroyed inhabitable world.
In the ecosystem, each organism is important regardless of the size.There is a mutual dependence between animals and plant species. Thisdependence is the one that ensures that all forms of life aresustained. Biodiversity has been put in grave danger by human actsthat are emerging every day to be incredibly dangerous in thedestruction of the biodiversity. Various human acts such as habitatdestruction and species habitat destruction is a primary cause of theextinction.
Evidence Supporting the Words of Wilson
People have continued to alter the environment by human actions insearch of natural resources and the need for expansion. This isevident in the ongoing destruction of cover forest in search forexpansion grounds and reversing of the rivers to create dams. Thedestruction of biodiversity in these case is evident in when anorganism that is adapted to a particular ecological condition in anenvironment. When the environment is eventually altered, the resultwill be conditions that the species is not used to, this only meansthat the organism cannot continue living .though the organism mayeventually adapt to the change, the adaptation is quickly overtakenby the fast growing acts of environment destruction. An example is adecrease in the number of specialized bees in Britain andNetherlands. This is an evidence of the result of habitatdegradation. The decline in the number of these bees also means thatthe plants that rely on the bees for pollination are also going todecline.in this there occurs a danger to all the dependent species.The plants depend on the bees, and so do human’s dependence on thebees. These are the evidence that the continued alteration of thephysical environment is going to have such immense effects that willtake a very long time to reverse.
Anybody who means well for the world would agree to the words said byWilson.in approval of his statement it is most evident thatpollution, human overpopulation and climate change surely have deathcausing an effect on biodiversity. Environment destructions are themajor hindrance of biodiversity. Whenever human destroy the habitatspecies that live in that environment are affected due to habitatreduction.
Explanation to the Wilson Words
Climate change and in particular the greenhouse effect has asignificant impact on the ocean species. Continued emission of carbonIV oxide gas into the atmosphere this result to formation of acidicrain that eventually finds its way into the sea. The acidic raincause changes in the chemical composition of the ocean, and thisdisrupts the life of the organisms in the ocean. This will eventuallylead to the death of the organisms that fail to adapt to the changes.Global warming causes climate change which interferes with thetemperatures and weather patterns. Change in weather patternseventually will have significant effects on the plants and animals.As the temperatures continue to rise, the number and range of speciesare going to decrease substantially[ CITATION Ish11 l 1033 ]. Forinstance, already the polar region has experienced an increase intemperatures. The number polar bears are declining as thetemperatures melt the sea ice that bears mainly depend on. This iswhy the polar bear has been listed as an endangered species andshould be protected by all means. Otherwise, the species will faceextinction if the global warming levels continue to rise.
To conclude, it is possible to highlight that the main cause of theloss of biodiversity is the human actions. Despite man being the mainbenefactor from the biodiversity through food medicine and naturalresources people have continued to exploit the biodiversity andmisused it in many ways. These are through the conversion of theecosystem to agricultural land and mining. These acts either resultsin the destruction of the natural habitat or change in its conditionswhich turn to be harmful to organisms. To avoid the long-termnegative results from the human acts, everyone should embark on theactions that promote and conserve biodiversity. Additionally,everyone should understand that they have a crucial role to playtowards the maintenance of the proper functioning of the ecosystem.
Baum, D. A., & Smith, S. D. (2012). Tree thinking: an introduction to phylogenetic biology. Greenwood Village: Colo. : Roberts.
Haldar, I. (2011). Global warming: the causes and consequences. New Delhi: Mind Melodies.
Hannah, L. J. (2012). Saving a million species: extinction risk from climate change. Washington, DC: Island Press.
Kolbert, E. (2014). The sixth extinction: an unnatural history. New York: Henry Holt and Company.
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