Causes and Consequences of Reduced Biodiversity Essay Example for Free

Causes and Consequences of Reduced Biodiversity Essay Causes and consequences of reduced biodiversity in tropical rain forests In many tropical countries, the majority of deforestation results from the actions of poor subsistence cultivators. However, in Brazil only about one-third of recent deforestation can be linked to cultivators. A large portion of deforestation in Brazil can be attributed to land clearing for pastureland by commercial and speculative interests, misguided government policies, inappropriate World Bank projects, and commercial exploitation of forest resources. For effective action it is imperative that these issues be addressed. Focusing solely on the promotion of sustainable use by local people would neglect the most important forces behind deforestation in Brazil. Brazilian deforestation is strongly correlated to the economic health of the country the decline in deforestation from 1988-1991 nicely matched the economic slowdown during the same period, while the rocketing rate of deforestation from 1993-1998 paralleled Brazils period of rapid economic growth. During lean times, ranchers and developers do not have the cash to rapidly expand their pasturelands and operations, while the government lacks funds to sponsor highways and colonization programs and grant tax breaks and subsidies to forest exploiters. Clearing for Cattle Pasture Cattle ranching are the leading cause of deforestation in the Brazilian Amazon. This has been the case since at least the 1970s: government figures attributed 38 percent of deforestation from 1966-1975 to large-scale cattle ranching. However, today the situation may be even worse. According to the Center for International Forestry Research (CIFOR), between 1990 and 2001 the percentage of Europes processed meat imports that came from Brazil rose from 40 to 74 percent and by 2003 for the first time ever, the growth in Brazilian cattle production 80 percent of which was in the Amazon was largely export driven. Factors * CURRENCY DEVALUATION—The devaluation of the Brazilian real against the dollar effectively doubled the price of beef in reals and created an incentive for ranchers to expand their pasture areas at the expense of the rainforest. The weakness of the real also made Brazilian beef more competitive on the world market [CIFOR]. * CONTROL OVER FOOT-AND-MOUTH DISEASE—The eradication of foot-and-mouth disease in much of Brazil has increased price and demand for Brazilian beef. * INFRASTRUCTURE—Road construction gives developers and ranchers access to previously inaccessible forest lands in the Amazon. Infrastructure improvements can reduce the costs of shipping and packing beef. * INTEREST RATES—Rainforest lands are often used for land speculation purposes. When real pasture land prices exceed real forest land prices, land clearing is a good hedge against inflation. At times of high inflation, the appreciation of cattle prices and the stream of services (milk) they provide may outpace the interest rate earned on money left in the bank. * LAND TENURE LAWS—In Brazil, colonists and developers can gain title to Amazon lands by simply clearing forest and placing a few head of cattle on the land. As an additional benefit, cattle are a low-risk investment relative to cash crops which are subject to wild price swings and pest infestations. Essentially cattle are a vehicle for land ownership in the Amazon. Colonization and subsequent subsistence agriculture A significant amount of deforestation is caused by the subsistence activities of poor farmers who are encouraged to settle on forest lands by government land policies. In Brazil, each squatter acquires the right (known as a usufruct right) to continue using a piece of land by living on a plot of unclaimed public land (no matter how marginal the land) and using it for at least one year and a day. After five years the squatter acquires ownership and hence the right to sell the land. Up until at least the mid-1990s this system was worsened by the government policy that allowed each claimant to gain title for an amount of land up to three times the amount of forest cleared. Poor farmers use fire for clearing land and every year satellite images pick up tens of thousands of fires burning across the Amazon. Typically understory shrubbery is cleared and then forest trees are cut. The area is left to dry for a few months and then burned. The land is planted with crops like bananas, palms, manioc, maize, or rice. After a year or two, the productivity of the soil declines and the transient farmers press a little deeper and clear new forest for more short-term agricultural land. The old, now infertile fields are used for small-scale cattle grazing or left for waste. Infrastructure Improvements Road construction in the Amazon leads to deforestation. Roads provide access to logging and mining sites while opening forest frontier land to exploitation by poor landless farmers. Brazils Trans-Amazonian Highway was one of the most economic development programs ever devised, and one of the most spectacular failures. In the 1970s, Brazil planned a 2,000 mile highway that would bisect the massive Amazon forest, opening rainforest lands to settlement by poor farmers from the crowded, drought-plagued north and development of timber and mineral resources. Colonists would be granted a 250-acre lot, six-months salary, and easy access to agricultural loans in exchange for settling along the highway and converting the surrounding rainforest into agricultural land. The plan would grow to cost Brazil US$65,000 1980 dollars to settle each family, an amazing amount for Brazil, a developing country at the time. Commercial agriculture Recently, soybeans have become one of the most important contributors to deforestation in the Brazilian Amazon. Thanks to a new variety of soybean developed by Brazilian scientists to flourish in rainforest climate, Brazil is on the verge of supplanting the United States as the worlds leading exporter of soybeans. High soybean prices have also served as an impetus to expanding soybean cultivation. Logging In theory, logging in the Amazon is controlled by strict licensing which allows timber to be harvested only in designated areas. However, there is significant evidence that illegal logging is quite widespread in Brazil. In recent years, Ibama Brazils environmental enforcement agency has made several large seizures of illegally harvested timber including one in September 2003 when 17 people were arrested for allegedly cutting 10,000 hectares worth of timber. Logging in the Amazon is closely linked with road building. Studies by the Environmental Defense Fund show that areas that have been selectively logged are eight times more likely to be settled and cleared by shifting cultivators than untouched rainforests because of access granted by logging roads. Logging roads give colonists access to rainforest, which they exploit for fuel wood, game, building material, and temporary agricultural lands. Fires Virtually all forest clearing, by small farmer and plantation owner alike, is done by fire. Though these fires are intended to burn only limited areas, they frequently escape agricultural plots and pastures and char pristine rainforest, especially in dry years like 2005. Many of the fires set for clearing forest for these purposes are set during the three-month burning season and the smoke produced creates widespread problems across the region, including airport closings and hospitalizations from smoke inhalation. These fires cover a vast area of forest. In 1987 during a four-month period, about 19,300 square miles of Brazilian Amazon were burned. The burning produced carbon dioxide containing more than 500 million tons of carbon, 44 million tons of carbon monoxide, and millions of tons of other particles and nitrogen oxides. An estimated 20 percent of fires that burn between June and October cause new deforestation, while another 10 percent is the burning of ground cover in virgin forest Mining Mining in the Brazilian Amazon presently results in limited deforestation due to crackdowns on informal miners known as garimpeiros. The pig iron industry may have the largest role in mining-driven deforestation by consuming wood to produce charcoal to fuel steel production.

What Can We Learn from Pseudogenes? Essay examples -- Biology

After many extensive molecular investigations of gene families, it has become apparent that a large majority of genes have multiple copies of themselves. This seemingly unnecessary amount of duplicates has led to further research, revealing that these ‘extra’ genes cannot successfully code for proteins (Proudfoot, 1980). These genes were therefore labeled as functionless sequences of DNA, and aptly named pseudogenes. This discovery poses many questions regarding the role and origin of these supposedly non-functional genes, but most importantly what else can we learn from them? Unfortunately, DNA that cannot be expressed into proteins is useless in regards to investigations of the molecular clock (Martin, 1990), however further research proves that we can learn a lot from pseudogenes. In order to explore what we can learn from pseudogenes, we need to understand them. Firstly, there are two main types of pseudogene, processed and unprocessed. Processed pseudogenes, also known as retropseudogenes, are sequences of transposable DNA that have been reverse transcribed back from mRNA, but have somehow failed to replicate crucial protein coding elements when assimilated back into the genome (Graur and Li, 2000: Skalka and Goff, 1993). Unprocessed pseudogenes can occur by simple replication of a pre-existing pseudogene, or due to adverse point mutations in ‘normal’ functioning genes that can trigger a frame shift in the original protein code. This frame shift can for example, lead to a mixture of premature stop codons and elimination of splicing sites, rendering the gene faulty (Li, Graur and Shuali, 1989). Initially it was believed that pseudogenes have no purpose, just selfish, parasitic DNA clogging up the genome (Orgel, Crick and ... ...e4573de165161150&searchtype=a> [Accessed 12th November 2010] (20) Nishikimi, M. et al. 1994. Cloning and Chromosmal Mapping of the Human Nonfunctional Gene for L-Guluno-y-Lactone Oxidase, the Enzyme for L-Absorbic Acid Biosynthesis Missing in Man*, The Journal of Biological Chemistry, [online] Available at: [Accessed 12th November 2010] (21) Sakai, H. Itoh, T. Gojobori, T. 2008. Processed Pseudogenes and Their Functional Resurrection in the Human and Mouse Genomes, Wiley: Online Library, [online] Available at: http://onlinelibrary.wiley.com/doi/10.1002/9780470015902.a0021000/abstract> [Accessed 12th November 2010] Websites (19) The True.Origin Archive: Exposing the Myth of Evolution.2010. Pseudogenes: Are They Non-Functional? [online] Available at: [Accessed 9th November 2010]

Jeanette’s childhood Essay

Jeanette’s childhood was much the same as Celie’s in the sense that it lacked a heterosexual relationship she could be influenced by. Jeanette’s parents aren’t shown to be in love; in fact they are hardly shown being together. When Jeanette asks her mother why she married her father, she replies not about love but about their responsibility to have a child and â€Å"dedicate it to the lord†(P. 10). Just like Celie, this lack of a loving parental relationship may have lead Jeanette to becoming a lesbian, as she hadn’t been exposed to any real love between a man and a woman. Throughout the two novels, neither primary character has a close relationship with a male. Instead, they find shelter with other women. The fact that Jeanette never has a close relationship with a man can give us hints to her inevitable sexuality, as she is not sexually attracted to them, shown when she â€Å"tried imagining him without his clothes on. Horrid. â€Å"(P. -), expressing her disgust of the male body and general distaste of men. Throughout Oranges Are Not The Only Fruit, she has a close relationship with a woman from church, Elsie. When Jeanette is sick in hospital, her mother rarely visits because she is busy, but Elsie comes every single day to â€Å"make me smile†(P. 29). This, as well as the fact Elsie sticks by Jeanette even after her lesbianism is revealed, almost seems to the reader that they have a parent/daughter relationship, where Elsie looks out for Jeanette and keeps her strong through hard times; Jeanette said â€Å"and my confidence restored (thanks to her)†(P. 30). Their closeness lasts until Elsie’s death. Her friendship and experiences with Mrs Jewsbury introduces Jeanette to homosexuality, which is a key turning point in the novel and can be seen to have had a huge impact on Jeanette’s sexuality. Like Jeanette, Celie shares closeness with women rather than men. While Jeanette’s distaste of men is more passive and subtle, Celie is hateful and wary of men because of the way she’s been treated by them. She lived in a time when men dominated the social hierarchy, so all the women had to stick together. This is shown when Celie meets Sofia, who has six brothers and five sisters, and says â€Å"all the girls stick together† (P. 39). It’s a possibility that Sofia’s words inspired Celie to find confidence in other women instead of suffering alone, because it is after this that Celie develops a close relationship with Sofia and Shug Avery,. The quilt Sofia and Celie make acts as a metaphor to show the power women can have when in numbers and the things they can achieve. Both Nettie and Mr. __’s sister, Kate, tell Celie â€Å"You got to fight†(P. 17 and 21) to encourage her, and Kate says â€Å"you deserve more than this†(P. 20), which helps Celie discover self-worth and gives her the confidence to leave Mr. ___. Kate shows Celie she is not alone, and the new dress Kate buys for her symbolises Celie’s newfound refuge with other women and the start of defining herself as a new, stronger person. Celie also seeks shelter from Shug, who she spends most of the novel admiring, and Shug takes on the responsibility of looking after her and introducing her to the idea of self-worth, empowering Celie as a woman. Their relationship is a major influence for Celie’s sexuality, despite the fact critic Trudier Harris calls it â€Å"The height of silly romanticism†1, implying it is unrealistic. I disagree with this, as I think their relationship is more sisterly than romantic, shown when Celie says â€Å"we sleep like sisters me and Shug† (P. 124) emphasizing how closely they’ve bonded. It is definitely not â€Å"silly† when looking at how much Celie gets out of their relationship, including redefining herself, questioning the word around her and discovering self worth, as stated before. Walker and Winterson both foreshadow the future lesbianism of Celie and Jeanette in various ways through symbolism and particular events. Jeanette’s lesbianism is hinted throughout the book, one example being the banana bar she is offered by the lesbian shopkeepers.

Post Traumatic Stress Disorder ( Ptsd ) And Its Effect On...

This essay discusses Post Traumatic Stress Disorder (PTSD) and its effect on combat soldiers involved in the Afghanistan and Iraq Wars. The goal of this paper is to inform others about what the soldiers deal with during and after combat and the different treatments available for them to cope with and hopefully overcome this disorder. PTSD is an anxiety disorder that develops when someone is witness to or experiences a traumatic event. PTSD has specific symptoms resulting from traumatic life threatening experiences. Symptoms resulting from the event must be present in a certain way over a period of time and for certain duration. A person who witnesses two or more traumatic events in a short amount of time can cause the brain to release the hormone glucocorticoid which helps control the response to stress. When this hormone is low or depleted and a second traumatic event takes place before the hormone is replenished in the brain, the stress becomes even more intensified thus increasing the person’s chances of developing PTSD. Most people who develop PTSD get better but 1 out of 3 people may continue to have some symptoms over their lifetime. The main symptom of PTSD is reliving the traumatic experience through flashbacks and nightmares. Other symptoms include soldiers avoiding situations, people or conversations that would remind them of the trauma. They tend to avoid memories by becoming numb, distant, or stop showing love towards others. Activities, such as sports, thatShow MoreRelatedWhat are the effects of Post-Traumatic Stress Disorder on a Soldier?1229 Words   |  5 PagesPost-Traumatic Stress Disorder We usually think of war injuries as being physical, although one of the most common war injuries is Post-Traumatic Stress Disorder (PTSD), and the effects can be devastating. 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