Pleistocene Conservation Essay
Conservation is the practice of protecting plants or animals, and their habitats. These plants and animals may be very close to extinction. North America experienced a big loss of megafauna at the end of the Pleistocene era (about 13 000 years ago). This started a program known as “Pleistocene re-wilding”. Re-wilding involves the reintroduction of extant species into areas where they became extinct in the past. This program aims to restore the evolutionary and ecological potential that North America lost all those ago, and in the process, prevent the extinction of the megafauna in Africa and Asia. This caused many opinions about North American re-wilding to form. The two main papers that will be discussed are Donlan et al, 2005 and Rubenstein et al, 2006. Both of these papers express different opinions.
Donlan et al, 2005, emphasizes that humans owe an ethical responsibility to redress the loss of megafauna during the Pleistocene era and to prevent further extinctions of extant megafauna. Humans …show more content…
over killed the large animals causing their numbers to drop dramatically and ultimately they became extinct. It is also believed that humans have diminished the evolutionary potential of megafauna in North America. Megafauna (herbivores and carnivores), are thought to be involved in the maintenance of biodiversity and therefore the loss of megafauna during the Pleistocene era has shaped the animals that are found today.
Africa and Asia are the only places where megafauna exists today. This is therefore another motivation for “Pleistocene re-wilding”. Most of the megafauna in Africa and Asia are endangered and therefore by relocating them their population numbers could increase. North America will act as a refugee to the African and Asian megafauna that are close to extinction.
Rubenstein et al, 2006 states that the introduction of megafauna into North America may have some negative impacts on the ecology of the habitats that already exist there. This is because exotic species will be introduced into habitats where their ancestors have been extinct for over 13 000 years. Donlan et al, 2005, believes that the flora in North America has gone unchanged since the Pleistocene extinctions but in Rubenstein et al, 2006 they believe this is not the true. They argue that because of the constant influx of genotypes and phenotypes among plant communities, they were allowed to evolve over 13 000 years especially since there were no large herbivores present.
Rubenstein et al, 2006 also states that the reintroduction of megafauna to North America could also bring new parasites and diseases into the ecosystems. This could lead to the disruption of food chains. The functioning of the Pleistocene ecosystems is also unknown so it is difficult to determine if the reintroduction of megafauna will restore or destroy the existing ecosystems.
Introducing grazers into grasslands could also produce a problem according to Rubenstein et al, 2006. Even though indigenous grazers can sometimes restore and shape grassland ecosystems, exotic grazers could wreak havoc instead. This is evident when one-humped camels were introduced into the desert ecosystems in Australia. These camels began eating the rare plant species. The introduction of large predators could also have unexpected results on their prey species. It is argued that if the Pleistocene re-wilding is first done on a small-scale basis, then these problems, if they exist, could be dealt with. However, this type of experiment would require too much time and generations in order for it to be an accurate representation.
A huge amount of financial and human resources would be required for Pleistocene re-wilding. The re-wilding process will be expensive because of land preparation and the translocation, protection and containment of the megafauna. The United States of America already holds many species of megafauna and this would reduce the costs considerably. However, the main challenge faced during re-wilding, would be to find large enough protected areas where the animals would be free to roam. In Africa today, large pieces of land are fenced off to protect surrounding towns and farms from any dangerous animals. These surrounding towns also benefit economically from tourism related jobs. Megafauna can benefit from ecotourism and strengthen conservation support because humans have developed emotional relationships with these large animals. However, if any of these large megafauna were to escape through the fencing, there would be an anti-conservation backlash. Elephants could destroy crops and lions and cheetahs could attack cattle and even people.
Rubenstein et al, 2006 argues that Pleistocene re-wilding cannot restore evolutionary potential of the extinct species, but it can maintain the evolutionary potential. The species that went extinct during the Pleistocene era could probably be more genetically different from their extant relatives, which may have continued to evolve over the years. Other papers have written that modern elephants, cheetahs and lions, are quite genetically different from their ancestors. Many people who object re-wilding state that the extant species of megafauna are not genetically identical to the extinct species that were once in North America.
There are also a few examples of reintroductions which can be used to support re-wilding. When the Tahki horse (which was endangered ) was introduced into another site in Mongolia, there numbers increased dramatically. Another successful reintroduction was of a rare Asian ass in Israel. The human population is growing very rapidly and this poses negative impacts on natural habitats and diversity.
There are many things to consider if the Pleistocene re-wilding is to take place. The two main goals of Pleistocene re-wilding are to prevent the extinction of the extant megafauna in Africa and Asia and to restore the evolutionary and ecological potential of megafauna in North America. Some problems that hang over the re-wilding process are genetics, land availability, and the negative impacts that the new megafauna could pose on the existing ecosystems. Donlan et al, 2005, justifies “Pleistocene re-wilding” on ethical and aesthetic grounds. They aim to rebuild an entire ecosystem with African and Asian megafauna that range over different tropic levels. Rubenstein et al, 2006 concludes that resources would be better spent on conserving endangered megafauna in their native habitats and reintroducing them into areas where they have only recently been wiped
out.
Donlan et al, 2005, emphasizes that humans owe an ethical responsibility to redress the loss of megafauna during the Pleistocene era and to prevent further extinctions of extant megafauna. Humans …show more content…
over killed the large animals causing their numbers to drop dramatically and ultimately they became extinct. It is also believed that humans have diminished the evolutionary potential of megafauna in North America. Megafauna (herbivores and carnivores), are thought to be involved in the maintenance of biodiversity and therefore the loss of megafauna during the Pleistocene era has shaped the animals that are found today.
Africa and Asia are the only places where megafauna exists today. This is therefore another motivation for “Pleistocene re-wilding”. Most of the megafauna in Africa and Asia are endangered and therefore by relocating them their population numbers could increase. North America will act as a refugee to the African and Asian megafauna that are close to extinction.
Rubenstein et al, 2006 states that the introduction of megafauna into North America may have some negative impacts on the ecology of the habitats that already exist there. This is because exotic species will be introduced into habitats where their ancestors have been extinct for over 13 000 years. Donlan et al, 2005, believes that the flora in North America has gone unchanged since the Pleistocene extinctions but in Rubenstein et al, 2006 they believe this is not the true. They argue that because of the constant influx of genotypes and phenotypes among plant communities, they were allowed to evolve over 13 000 years especially since there were no large herbivores present.
Rubenstein et al, 2006 also states that the reintroduction of megafauna to North America could also bring new parasites and diseases into the ecosystems. This could lead to the disruption of food chains. The functioning of the Pleistocene ecosystems is also unknown so it is difficult to determine if the reintroduction of megafauna will restore or destroy the existing ecosystems.
Introducing grazers into grasslands could also produce a problem according to Rubenstein et al, 2006. Even though indigenous grazers can sometimes restore and shape grassland ecosystems, exotic grazers could wreak havoc instead. This is evident when one-humped camels were introduced into the desert ecosystems in Australia. These camels began eating the rare plant species. The introduction of large predators could also have unexpected results on their prey species. It is argued that if the Pleistocene re-wilding is first done on a small-scale basis, then these problems, if they exist, could be dealt with. However, this type of experiment would require too much time and generations in order for it to be an accurate representation.
A huge amount of financial and human resources would be required for Pleistocene re-wilding. The re-wilding process will be expensive because of land preparation and the translocation, protection and containment of the megafauna. The United States of America already holds many species of megafauna and this would reduce the costs considerably. However, the main challenge faced during re-wilding, would be to find large enough protected areas where the animals would be free to roam. In Africa today, large pieces of land are fenced off to protect surrounding towns and farms from any dangerous animals. These surrounding towns also benefit economically from tourism related jobs. Megafauna can benefit from ecotourism and strengthen conservation support because humans have developed emotional relationships with these large animals. However, if any of these large megafauna were to escape through the fencing, there would be an anti-conservation backlash. Elephants could destroy crops and lions and cheetahs could attack cattle and even people.
Rubenstein et al, 2006 argues that Pleistocene re-wilding cannot restore evolutionary potential of the extinct species, but it can maintain the evolutionary potential. The species that went extinct during the Pleistocene era could probably be more genetically different from their extant relatives, which may have continued to evolve over the years. Other papers have written that modern elephants, cheetahs and lions, are quite genetically different from their ancestors. Many people who object re-wilding state that the extant species of megafauna are not genetically identical to the extinct species that were once in North America.
There are also a few examples of reintroductions which can be used to support re-wilding. When the Tahki horse (which was endangered ) was introduced into another site in Mongolia, there numbers increased dramatically. Another successful reintroduction was of a rare Asian ass in Israel. The human population is growing very rapidly and this poses negative impacts on natural habitats and diversity.
There are many things to consider if the Pleistocene re-wilding is to take place. The two main goals of Pleistocene re-wilding are to prevent the extinction of the extant megafauna in Africa and Asia and to restore the evolutionary and ecological potential of megafauna in North America. Some problems that hang over the re-wilding process are genetics, land availability, and the negative impacts that the new megafauna could pose on the existing ecosystems. Donlan et al, 2005, justifies “Pleistocene re-wilding” on ethical and aesthetic grounds. They aim to rebuild an entire ecosystem with African and Asian megafauna that range over different tropic levels. Rubenstein et al, 2006 concludes that resources would be better spent on conserving endangered megafauna in their native habitats and reintroducing them into areas where they have only recently been wiped
out.