The Pleistocene epoch was a time period of almost 2 million years of repeating glaciation around the globe. This epoch was known for its megafauna that roamed the Earth during the last great ice age. Although this was a time of mass extinction for species that could not adapt to the climate changes, many mammals and vertebrates that can be identified today were found during this time (Zimmermann, 2013). The Pleistocene epoch is an important foundation for understanding life that exists today, including carnivores, herbivores as well as the evolution of humans.
Fossil preservation has always been the most accurate way to determine what species lived during a specific time period. Through correlations and radiometric dating, time periods have become more accurate and being able to tell what lived during those times became possible. Although conditions have to be correct for fossilization, Pleistocene fossils are widespread and often well preserved. In the La Brea tar pits of present day Los Angeles, hundreds of thousands of preserved bones have been found that give a good idea of the animals that were present during this time. Many of the animals preserved are animals that can still be found today and would be found in the Los Angeles area if not for urbanization. Animals that were present during this time include camels, mammoths, and saber-toothed cats among others (Harris and Jefferson, 1985). Below is a picture of a saber-tooth fossil found in the La Brea tar pits.
The species that were present were not exclusive to North America, but lived all over the globe. During the Pleistocene, saber-tooth cats were present on all the continents as very fierce mammal carnivores that would hunt large herbivores such as mastodons. As th...
... middle of paper ...
...redators and were well established as creatures that could survive the harsh climate changes. There were also many flightless birds that didn’t do as well because of the competition for food and water due to glaciation and predators attacking them (Zimmerman, 2013).
The Pleistocene epoch is a well-known time period thanks to the glorification of now extinct megafauna as well as the proximity to our current epoch. Through the rapid climate changes and glaciation that occurred many times during this epoch, the fauna
could either survive through adaptation or die off due to an inability to adapt rapidly enough. All different types of animals, carnivorous and herbivorous mammals, birds, and reptiles, lived during the Pleistocene epoch and thanks to preservations such as the La Brea tar pits, we are able to observe and study the life forms of millions of years ago.
The re-wilding of North America is basically a conservation strategy (Donlan 2005), aimed at restoring the Pleistocene era (Donlan 2005, Rubenstein et al. 2006). This could be achieved by reintroducing African and Asian megafauna, these species are phylogenetically known to be direct descendents of the extinct Pleistocene species or animals of similar taxa (Donlan 2005, Rubenstein et al. 2006). Re-populating North America is essential for both ecological and evolutionary potential (Donlan 2005) and also economic gain (Donlan 2005, Rubenstein et al. 2006). In this paper I will be discussing the main arguments presented by two papers regarding the Pleistocene North America re-wilding. The first paper is written by Donlan (2005), it is a commentary paper in which he proposes the plan of re-wilding North America based on his opinions. The second paper is by Rubenstein et al. (2006), it is a research paper where he outlines some facts contrary to Donlan (2005)’s paper, unlike Donlan (2005)‘s paper his arguments were supported by variety of recent Scientific published papers which are relevant to the topic discussed.
Americas by 14,000 ago” (O’Brien 12), after large portions of North America encountered the last ice age, which
Rapidly evolving throughout the late Pleistocene to the early to mid Holocene, hunter-gatherer-fisher societies hunted megafauna creatures in a systematic and ethical way. When one species migrates to a different ecosystem, that species is not usually recognized as a threat to other species. Survival, during the late Pleistocene and Holocene era, was one of the most important aspects to life. Any organism, regardless of size, living within their environment had to stay alive and reproduce. During these two eras, it seems...
Mountain building and climate changes happened often in this period, as well as the breakup of Pangaea. Mammals were very popular and they were very different and everywhere. The climate was much colder now. The animals adapted to their environment and diets; meat eaters had sharp teeth for cutting and ripping, rodents had self-sharpening front teeth for gnawing and plant eaters had molars for grazing plants.
The range for the jaguar is fairly extensive. Its historical range started in the southern United States and stretched all the way down through Central America to cover most of South America. Fossils have been found as far north as Missouri, Illinois, and Tennessee with jaguars they may have weighed in at around 420 pounds (Museum). Now, due to various reason such as habitat fragmentation, hunting, and other human interference, the range starts in the southwestern area of the United States. It was thought that the jaguar was extirpated from the United States but sightings have been reported in Arizona, New Mexico, and Texas. The northern extent of the range has receded southward about 1000 kilometers and the southern extent about 2000 kilometers northward. The range still flows through Central America but it has become extinct in El Salvador and Uruaguy (IUCN). The southern tip of the range occupies mid to southern South America, covering parts of Argentina and Brazil. The numbers typically increase from north to south. Jaguars are usually found in dense rain forest and that is a l...
Earth has experienced many episodes of dramatic climate changes with different periods in earth history. There have been periods during which the entire planet has been covered in ice and at another time it has been scorchingly hot and dry. In this regards, earth has experienced at least three major periods of long- term frigid climate and ice ages interspersed with periods of warm climate. The last glacial period which current glaciers are the result of it, occurring during the last years of Pleistocene, from approximately 110,000 to 10,000 years age (Clayton, 1997). Indeed, glaciers present sensitive indicators of climate change and global warming and by estimating and monitoring the dynamic evolution of these ice masses, several aspect of climate change impact on environmental phenomena can be revealed.
The Woolly Mammoth saw periods of glaciation, when temperatures were reduced, and the Earth entered an Ice Age. They lived in dry northern ecosystems which they were well adapted to with their characteristic long shaggy coat. However, most of the time there were periods of snow. They are also associated with grassy plains which. Although the grass was not very nutritious, they grew in large enough amounts that it became part of their diet. They also fed on saplings of trees such as birch. Because of a grown Woolly Mammoth’s size and sheer strength, the Woolly Mammoth didn’t have many predators. Those who were preyed upon were juvenile wooly mammoths who were targeted by big cats like Homotheriums and, later, the early
Examining the Cretaceous-Paleogene Extinction Event Over 98% of all organisms that have lived on Earth are now extinct. A mass extinction event occurs when a large number of species die out within a small time frame (relative to the age of Earth). Mass extinctions are intensively studied for both cause and effect, as there is usually room for debate regarding catalysts that precede the extinction and the massive influx of new biological species that follows. There have been five major mass extinctions, dubbed the “Big Five,” that have wiped out at least 50% of the species living at those times. The most well-known mass extinction of the Big Five, with the decimation of every species of non-avian dinosaur, is the Cretaceous-Paleogene extinction event (K-Pg).
Changing seasons was to the advantages of mammals who were warm blooded over reptiles who couldn’t control their metabolic temperatures. Thus, many reptiles, such as lizards and crocodiles, did not evolve the way mammals did since they weren’t able to flourish as much as rodents and hoofed animals. Due to this climate change, it was crucial that animals evolve in order to develop the certain traits, characteristics, and skills to be able to survive and adapt to this new environment. When the forests began to cool, mammals evolved to possess the traits of being a scavenger and being short legged. As a result of the insect group expanding, it provided a more plentiful amount of food to the small sized mammals, which further increased their population. In account of the growth of the polar ice cap and it attaining more ocean water, sea levels dropped and connected certain areas of Asia and Europe together which had once been separate, which allowed species to travel from one area to the other since they were now connected and can explain how one species migrated from one continent to the other. However, many herbivores could not adapt to this
Fossil records from 12,000 years ago show the appearance of the Large Mammals followed by Paleoindian in Eastern North America. Another piece of the fossil record shows that the appearance of Paleoindian brought about the disappearance of the large mammals. Some people feel that, "there is evidence to suggest that rapacious hunting practice of the paleohunters in North and South America 12,000 years ago may have caused…The demise of the very animals they hunted" (Powell 1987). The evidence Powell suggests is that the extinction of a large mammal is usually followed by the appearance of humans in the fossil record. This coincidence is not only seen in the fossil records of North and South America but Europe and Asia as well. Powell shows that as human populations increased local extinctions of large mammals occurred. This was probably due to the fact that there were not many predators that could hunt the large mammals except man. For this reason it is also highly like likely that man and large mammals did not co-evolve which ultimately resulted in the extinction of large mammals.
most of the same factors to keep it alive. Since the Woolly Mammoth has been
There were 5 mass extinctions in the past, with the latest one more known to man, the Cretaceous-Tertiary mass extinction that caused the wiped out of the dinosaurs. Though the latest one happened 65 million years ago, something representing this phenomenon of mass extinction is underway in our era. While past mass extinctions were caused by natural forces, and asteroid, climate change and sea level’s changes were thought to be the culprit, this time the actor behind is not natural, and it is us Human Beings. It might occur to many that the current trend of animal extinction has no consequences on us, but in fact it is not true. Many of the endangered species does matter to us significantly. In this paper, using examples of some neglected critical endangered species as main headings, I will look into different forms of human activities that had led to their losses, and also more importantly how these losses could have impacted on us.
The separation of the Paleolithic and Neolithic Ages mark a great divide in the lives and cultures of prehistoric peoples. Many aspects of everyday life were modified to suit a new standard of living. Society, Economy, and Technology were greatly affected by the "Agricultural Revolution" that spawned the Neolithic Age.
Wooly mammoth. Atlantic gray whale. Large sloth lemur. Dodo bird. Silver trout. Baiji white dolphin. Saber-toothed tiger. These are just a few of the many extinct species. All extinct species go through a process that leads them to extinction. Endangered species are on the brink of extinction caused by natural causes and humanity. The numbers of these species have increased yearly due to different reasons, and it is because of these reasons they become endangered.
Perhaps it is too premature to explore an additional paleoecological implication, namely that the human that had settled in Australia from the land bridge were in competition with Thylacoleo carnifex for the resources of meat from the megafauna (Horton and Wright 1981). To date, there has not been any archeological discovery that has been found which from fossil record predicts that humans might have been killing and eating the megafauna and depleting the supply of food for Thylacoleo carnifex. From the fossil record, we can only describe how the animal could have lived and its diet. There is not yet enough evidence that proves that humans killed off the lions. However, like most of the megafauna that died off after the ice age, the Thylacoleo carnifex could not adapt well enough (Trivedi 2004).