As far as we can say, intelligent, modern humans have been around for roughly 50,000 years, and in that time have altered the earth beyond recognition (Morrison, 2006). Most evident in recent years, the rapidity of technological advances both during and post the industrial revolution has been astonishing, but has come with a hefty ecological price. There is wide scientific consensus that we are presently witnessing the obsolescence of species on a prodigious scale. We are now having to accept the possibility that humans might just be a contributing influence.
Predominantly we rely on one measure to compare the rate of species loss between various moments in history. The background rate of extinction is approximately 1 extinction per
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The Mascarene island of Mauritius’ national emblem remains to this day the dodo, despite the fact that it is one of the most infamous cases of manmade extinction. Previously isolated from humans, the largest member of the pigeon family possessed a curious and innocently trusting nature when sailors first arrived on the island in the early 1600’s. Despite its flesh being absurdly tasteless, the dodo’s gullibility and ‘lack of leggy zip’ (Bryson, 2003) proved an irresistible target for young seamen and their pets. So blissfully ignorant was the raphus cucullatus that you had only to set one squawking and all its friends from the immediate surroundings would rush to your side. Within seventy years of our first meeting with the dodos the last one was dead, pointlessly hunted to extinction by humans and the animals we introduced (Flannery & Schouten, 2001).
Myriad methods exist through which we are directly and indirectly placing pressure on flora and fauna. A growing global population puts more strain on the agriculture industry, triggering agrarian and urban expansion. Land clearing reduces habitat size, while large environmental enterprises such as the damming of rivers can either flood or dehydrate vast areas of terrain. Although not so common nowadays, introduced species have in the past entirely missed their intended purpose, eventually poisoning, killing or in the very least competing with native animals. Diseases and infections can also
The first example of human manipulation of changes within the biosphere is through expansion. The rapid growth of the population has led to expansion in development; the need for more space is causing strain on other living organisms such as plants and animals. Human procurement of forest, grass, and wetlands has weighed on the animal population heavily. As a result of this domination, animals have lost areas they use to thrive in, causing migration and in more serious cases extinction. Animals are a prevalent source of protein for humans, and when a species is threatened by extinction, it not only disrupts the balance of the ecosystem, but it also disrupts the food chain. The more resources that are required to sustain human life, the bigger the need to migrate to surrounding areas in a short period of time (Haines).
The scale and pace of change is dramatic; for example, the extinction of species is occurring at around 100-fold pre-human rates4. The population sizes of vertebrate species have, on average, declined by half over the last 45 years5. More than 2.3 million km2 of primary forest has been felled since 20006. About
There have been five major mass extinction on earth triggered by a distinguishable event, but in The Sixth Extinction: An Unnatural History, Elizabeth Kolbert writes of the narrative of the sixth extinction caused directly by human impact. The book identifies the effects of human activity on how, over humans history on earth, the natural world has been affected. Every environmental impact stems into three basic groups of global problems to nature: Pollution, Habitat loss and Invasive Species. Kolbert explains that each impact can be traced back to one source, human industrial development. With each impact various types of life in the natural world are affected. Deforestation, urbanization, and sea level rise contribute to habitat loss worldwide. When humans began to travel they also brought invasive species and disease along with them; as boats only became bigger more and more invasive species travel. This reverse engineering of the planet species, brings new species that don’t have any natural predators, thus having an easier time driving native species out to endangerment or extinction. The different outcomes that come from human pollution is separated throughout the book, but the idea remains constant; with the development of human culture, pollution has drastically impacted a vast extent of species habitats and their environment.
Extinction: Most species become extinct because they can’t cope with the environmental change, and also because of introduced species that turned into competitors for
Long-term survival of a species depends on its ability to adapt to changing environmental conditions (Murphy, 1994). Genetic diversity within a species, which has taken 3.5 billion years to evolve, makes adaptations to these changing environments possible. Unfortunately, the rate of extinction of genetically diverse organisms is rapidly increasing, thus reducing this needed biodiversity, largely due to the human impacts of development and expansion. What was an average of one extinction per year before is now one extinction per hour and extinct species numbers are expected to reach approximately one million by the year 2000 (WWW site, Bio 65). As a result governmental and societal action must
Forests have been cut, crops planted, pastures seeded, and urban areas paved. One of the most troubling consequences of human modification of ecosystems is an ongoing loss of species and therefore a loss of biodiversity around the world. The current extinctions have a human cause: habitat loss (such as clearing of tropical rainforests); the introduction of invasive species; unregulated hunting and fishing; and pollution of water, air, and
Has Earth entered into a new geologic epoch, characterized by human influences? A recent study, spear-headed by the British Geological Survey, has come to the conclusion that man’s global impact has become distinct enough to end the Holocene and effectively begin the Anthropocene. Published in Science, the study identifies how man’s impact on our oceans, resources, climate, and vegetation has altered the sedimentary makeup of the planet. Massive species invasions, increased rates of extinction, genetically modified plants, redistributed metals, sediment, hydrocarbons, fossils, increased levels of carbon, nitrogen, and phosphorus all combine to create signals that geologists interpret to denote a break in the Holocene
During Late Pleistocene a megafaunal mass extinction took place. It’s still debated whether humans are to blame for this, since this megafaunal extinction happened after the arrival of humans or if climate change is entirely to blame. Fossil evidence has been of great help in finding what factors might’ve caused this extinction. This mass extinction that took place is related to the Anthropocene because if humans were the main cause, humans need to be more careful now because their actions may lead to more extinctions. The observations made were the types of species that went extinct with climate change, and what humans did to contribute to this mass extinction.
Influence on ecosystems range from human causes like the bulldozing of a forest to natural causes like a fire or a flood. In recent times, the introduction and spread of invasive species has transformed native communities rapidly and, in some cases, created irreversible damages. In the Earth’s history, changes have often occurred in the ecosystems. For example, glaciers and the retreat of glaciers cause wide-spread changes. However, although change is a constant in ecosystems, animals and habitats often cannot adapt to the rapid alterations of non-natural stresses. Harm to the environment from the introduction of invasive species occurs through changes in the habitat and declines in the native species. Invasive species
In the article “Earth Without Humans,” Bob Holmes describes what negative impacts humans are having on our
Since the beginning of life itself, some species have lived and prospered while other species have gone extinct never to be seen again by mankind. Because of this, some would claim that extinction is natural and not significantly problematic to the world that we live in. Others, however, understand that due to climate change, habitat loss, and poaching, more and more species are becoming endangered which leads to a chain reaction that can be devastating to ecosystems. Species such as the Chinook salmon, gorillas, tropical sharks, and polar bears are all directly affected by climate change, species such as northern spotted owls, Sumatran tigers, and lemurs are greatly harmed due to habitat loss, and species such as the sea turtle, Javan rhinoceros, African elephant, and the Red-Fronted Macaw are all affected by poaching driving them all closer and closer to becoming extinct.
One specific way that humans have begun the process of world extinction is through their incessant meddling with the environment. Not only do people destroy the environment with our wreckage and pollution, but the human race has introduced species into other ecosystems, causing massive repercussions. Referred to as invasive species, their introduction into a
Scientists calculate that without humans about one to five species would die a year, which is considered the background rate of extinction. But in our current society human activities are destroying many of the chances these animals need to survive. We as a planet are killing species at
Since before the industrial evolutions humans have been pumping green house gasses—carbon dioxide, water vapor, methane, nitrous oxide, and chlorofluorocarbons— into the atmosphere however, it wasn’t until recently that the amounts being produced are shoving the Earth into a sixth extinction. While the causes of this upcoming extinction are constantly debated on it has earned itself the name Holocene extinction. This name is derived from the theory that humans are the main contributors to this extinction. To investigate the cause Elizabeth Kolbert, and American journalist and professor at Williams College, took the world on a wild and saddening journey on the human contribution to this looming extinction in her novel, The Sixth Extinction; An Unnatural History. Not only does Kolbert’s book explain how humans have contributed to global warming and its effects on life on land but also ocean acidification and how life under the sea has changed over the years.
The health of the earth degrades with the destructive activity of human beings. A recent study by a group of scientists looked at twenty four different services that the earth’s ecosystems provide for humans, ecosystem services, and found that fifteen of them are in need of desperate help (Gazette 31 March 2005). These services are vital to the survival of both human and nonhuman life and include filtering water and providing nutrient rich soils and ocean waters. Many of the members of these various ecosystems are also decreasing in numbers. In a British survey of bird populations found that in the 200 birds of Britain tracked there was about a 54% population decrease between the 1968-1971 tacking period and the 1988-1991 tacking period. In two other surveys of 254 native plant species from the same area there was a decrease of about 28% during the past 40 years. Humans are pushing the sixth mass extinction (Gazette March 19, 2004).