Biodiversity essays

Biodiversity essays Extinction is defined as the end of existence of a group of organisms, caused by their inability to adapt to changing environmental conditions. Throughout the existence of our planet there have been large amounts of species extinctions. For instance, the dodo, a species of flightless pigeon formerly living on the island of Mauritius, became extinct in 1665. About 10,000 to 12,000 years ago, the most of the woolly mammoths and the last of the mastodons, both members of the elephant family, died. Also about 245 million years ago at the end of the Paleozoic Era, an entire class of primitive marine animals called trilobites disappeared forever. Over the years we have learned that extinction is a natural and ongoing phenomenon. In effect, of the hundreds of millions of species that have lived on Earth over the past 3.8 billion years, more than 99 percent are already extinct. This extremely high rate of extinction can be linked to several factors. Some of this happens as the natural result of competition between species, and is known as natural selection. According to natural selection, living things must compete for food and space. Those species incapable of adapting are faced with imminent extinction. This constant rate of extinction is sometimes called background extinction. Normal rates of background extinction are usually about five families of organisms lost per million years. Due to several fossil finding, we know that not all extinctions are constant and gradual, some are unpredictable and extreme. The cause of these large-scale extinctions is always dramatic environmental change that produces conditions too severe for organisms to endure. Environmental changes of this caliber result from extreme climatic change, such as the global cooling observed during the ice ages, or from catastrophic events, such as meteorite impacts or widespread volcanic activity. Extinction is a timeless trend, in fact, most scientists agree that life...

Consequences of the Conquest of the Aztecs

Consequences of the Conquest of the Aztecs In 1519, conquistador Hernan Cortes landed on Mexicos Gulf coast and began an audacious conquest of the mighty Aztec Empire. By August of 1521, the glorious city of Tenochtitlan was in ruins. The Aztec lands were renamed New Spain and the colonization process began. Conquistadors were replaced by bureaucrats and colonial officials, and Mexico would be a Spanish colony until it began its fight for independence in 1810. Cortes defeat of the Aztec Empire had many ramifications, not the least of which was the eventual creation of the nation we know as Mexico. Here are some of the many consequences of the Spanish conquest of the Aztecs and their lands. It Sparked a Wave of Conquests Cortes sent his first shipment of Aztec gold back to Spain in 1520, and from that moment, the gold rush was on. Thousands of adventurous young Europeans - not only Spanish - heard tales of the great riches of the Aztec Empire and they set out to make their fortune just like Cortes had. Some of them arrived in time to join Cortes, but most of them did not. Mexico and the Caribbean soon filled with desperate, ruthless soldiers looking to take part in the next great conquest. Conquistador armies scoured the New World for wealthy cities to loot. Some were successful, like Francisco Pizarros conquest of the Inca Empire in western South America, but most were failures, like Panfilo de Narvaez disastrous expedition to Florida in which all but four men out of over three hundred died. In South America, the legend of El Dorado - a lost city ruled by a king who covered himself in gold - persisted into the nineteenth century.  Ã‚  Ã‚   The Population of the New World was Decimated The Spanish Conquistadors came armed with cannons, crossbows, lances, fine Toledo swords and firearms, none of which had ever been seen by native warriors before. The native cultures of the New World were warlike and tended to fight first and ask questions later, so there was much conflict and many natives were killed in battle. Others were enslaved, driven from their homes, or forced to endure starvation and rapine. Far worse than the violence inflicted by the conquistadors was the horror of smallpox. The disease arrived on the shores of Mexico with one of the members of Panfilo de Narvaez army in 1520 and soon spread; it even reached the Inca Empire in South America by 1527. The disease killed hundreds of millions in Mexico alone: its impossible to know specific numbers, but by some estimates, smallpox wiped out between 25% and 50% of the population of the Aztec Empire. It Led to Cultural Genocide In the Mesoamerican world, when one culture conquered another - which happened frequently - the winners imposed their gods upon the losers, but not to the exclusion of their original gods. The vanquished culture kept their temples and their gods, and often welcomed the new deities, on the grounds that their followers victory had proven them strong. These same native cultures were shocked to discover that the Spanish did not believe the same way. Conquistadors routinely destroyed temples inhabited by devils and told the natives that their god was the only one and that to worship their traditional deities was heresy. Later, Catholic priests arrived and began burning native codices by the thousands. These native books were a treasure trove of cultural information and history, and tragically only a few battered examples survive today. It Brought Forth the Vile Encomienda System After the successful conquest of the Aztecs, Hernan Cortes and subsequent colonial bureaucrats were faced with two problems. The first was how to reward the blood-soaked conquistadors who had taken the land (and who had been badly cheated out of their shares of the gold by Cortes). The second was how to rule large swaths of conquered land. They decided to kill two birds with one stone by implementing the encomienda system. The Spanish verb encomendar means to entrust and the system worked like this: a conquistador or bureaucrat was entrusted with vast lands and the natives living on them. The encomendero was responsible for the safety, education and religious well-being of the men and women on his land, and in exchange, they paid him with goods, food, labor, etc. The system was implemented in subsequent conquests, including Central America and Peru. In reality, the encomienda system was thinly-disguised slavery and millions died in unspeakable conditions, particularly in mines. The N ew Laws of 1542 tried to rein in the worst aspects of the system, but they were so unpopular with colonists that Spanish landowners in Peru went into open rebellion. It made Spain a World Power Before 1492, what we call Spain was a collection of feudal Christian Kingdoms which could barely put aside their own squabbling long enough to oust the Moors from Southern Spain. One hundred years later, a united Spain was a European powerhouse. Some of that had to do with a series of efficient rulers, but much was because of the great wealth flowing into Spain from its New World holdings. Although much of the original gold looted from the Aztec Empire was lost to shipwrecks or pirates, rich silver mines were discovered in Mexico and later in Peru. This wealth made Spain a world power and involved them in wars and conquests around the globe. The tons of silver, much of which was made into the famous pieces of eight, would encourage Spains Siglo de Oro or golden century which saw great contributions in art, architecture, music, and literature from Spanish artists.   Sources: Levy, Buddy. . New York: Bantam, 2008. Silverberg, Robert. The Golden Dream: Seekers of El Dorado. Athens: the Ohio University Press, 1985. Thomas, Hugh. . New York: Touchstone, 1993.