Argumentative Essay On Mammoth Evolution

Faith and Surovell hypothesize a statistical analysis will uncover whether a temporally spread out extinction or a quick extinction killed North America’s Pleistocene mammals, a debate that has split paleontologists and archaeologists into two diametrically opposed sides for years. (Faith and Surovell, 2009). The debate on the extinction method has been heated due to the absence of fossil records of 19 of the 35 genera (Faith and Surovell, 2009). Faith and Surovell test whether finding only 16 genera in the fossil record in the terminal timeframe (between 12,000 and 10,000 radiocarbon years ago or between about 11,800 - 9,400 B.C.) is a result of a sampling error, or an extinction happening over a long period of time (Faith and Surovell, 2009).

Summary and Critique of Twilight of the Mammoths: Ice Age Extinctions and the Rewilding of America

During the middle to late Eocene and into the Oligocene epoch several other members of the equids, with distinct evolutionary changes, existed including the Orohippus, Epihippus, Mesohippus, and Miohippus. The Orohippus developed from the Hyracotherium and shared many of the same traits. One major change was that the first and second toes disappeared. Another significant change occurred in the teeth. The last premolar changed to become like a grinding molar. Also the crests were more defined showing that the Orohippus’s diet had changed to a tougher plant material. During the middle Eocene a descendant of Orohippus appeared. The Epihippus still resembled a dog-like animal. It had four padded toes on the front leg, and three on the back leg. However, the teeth changed more drastically with two of the premolars changing to grinding molars. Now there were five grinding cheek teeth with low crowns. As

If the null hypothesis cannot be rejected, the chi-square test was unable to detect a statistically significant difference between observed and expected data. When applying this test to the stickleback experiment, the development of pelvic structures will be compared in order to accept or reject the null hypothesis. If it is rejected, the alternate hypothesis is correct- the environment did have an impact on the development of the pelvic spines, proving that natural selection can drive the evolution not just of simple traits like coat color or body size, but also of complex traits like the size and shapes of body structures and

From its early stages as a 40 cm tall, 25 kg Eohippus to its current state as a 1.6 meter tall, 500 kg beast, every step can be traced through an abundance of fossils located mostly right here in the United States. While the changes in equids from their beginnings until now are drastic, I found it interesting that it was not necessarily gradual. Most of the changes in size, structure and teeth did not happen until the Miocene, upon which the development was rapid. Figure 5 shows the mass of Equid genera in comparison to when they lived. For the first half of equid development, barely any change occurred. This displays how important environmental factors are in the evolution of species; without the emergence and prominence of open grasslands in the Miocene, horses as we know them today would almost certainly not

Phylogeography is a field of study that implements biogeography and genetics to understand the geographic distribution of a species. It is concerned with historical principles and processes that influence evolution and speciation. The tiger is an evolutionary wonder; it is a prime example of the responsiveness that some species have to changing climatic conditions. The tiger once had the largest geographic distribution of all cat species; subspecies adaptations allowed them to live in a large range of habitats throughout the Asian continent making it a perfect candidate for the study of phylogeography. This review will examine the evolutionary history of the tiger and will explain how the species was affected by climatic fluctuations and biogeographic processes during the Plestocene epoch.

The concept of species going extinct was not always accepted as fact. It wasn’t until the discovery of the American mastodon that the concept of extinction was even considered. With the discovery of the bones, When the bones were discovered, many theories were constructed, such as that the bones were actually from multiple creatures, or that this was simply an undiscovered species and hadn’t been found. The discovery of other mysterious, lost species led to the concept of extinction, and the idea that the mammoth was indeed a species that, while it once was prevalent, no longer roamed the Earth. In chapter three, Kolbert writes about her visit to Iceland in which she learned about the loss of the great auk, a three foot tall bird reminiscent of a large penguin or puffin. She then proceeds to write the tragedy of the great auks, that being that they were regularly hunted and killed. The final moments of the great auk’s species can be tracked down, as they were captured and sold and their only egg was broken. The concept of human-caused extinctions wasn’t new, as Darwin wrote about how the Galápagos tortoises were dying out very rapidly due to overhunting. The extinction of species stems from events that drastically affect them, be them environmental changes to human

Paul S. Martin, Twilight of the Mammoths: Ice Age Extinctions and the Rewilding of America, University of California Press, 2005, Prologue and Chapter 2

George G. Simpson George Gaylord Simpson is known as being one of the most influential empirical paleontologist of the twentieth century due to his crucial contributions in the modern evolutionary synthesis. He is known for his expertise in extinct mammals and their intercontinental travels; more specifically, discovering evidence in fossils for the theory of linear evolution in horses. Furthermore, Simpson is an important figure in the studies of paleontology due to his exceptional dedication to his career through his education, which is shown through his many achievements throughout his life. Background Simpson was born in Chicago, on June 6th, 1902, as the youngest child of three and only son. His father, Joseph A. Simpson, was a successful

A. Rus hoelze et al, studied the impact of intense hunting of Northern Elephant Seals in the late 19th century, whose genetic variation reduced due to this bottleneck. This reduced their population size to just about 20. They found that although it has since rebounded to over 30K now but compared to their southern counterparts i.e., Southern Elephant Seals they have much less genetic variation. The Southern Elephant Seals didn’t went through this bottleneck event. It is clear that the genes of Northern Elephant Seals still carrying the marks of this bottleneck.

It is estimated that mammoths had the largest biome on the plant at an estimated 1 square kilometer per mammoth (Zimov, 2014). Herbivores of the time ranged from under 45 kilograms to well over 1000 kg, making for a wide range of diversity within the speciation (graph below). While many of these mammals were preyed upon by the carnivores, some were simply too large to be killed by single predators, causing them to be relatively immune to predation (Rodriguez, Alberdi, Azanza, Prado, 2006).

"New standards pointed out about that discrepancies in a molecular evidence has challenged the evolutionary theory of common ancestry of all living things and that whether microevolution can be extrapolated to explain macro evolutionary changes is controversial".(LeBeau, 2007)

This theory can be applied to the procoptodon and its modern day counter-part the red kangaroo. The procoptodon has noticeable structural differences to the red kangaroo such as having a short snout, having a large horse hoof like toe on each foot and on each paw they had two extra-long fingers. Opposing to the red kangaroo having a long snout, four similar length toe feet and equal length fingers on their paws. A possible theory of why these structural features changed is that the red kangaroo’s diet is mainly sourced of grass, opposed to the procoptodons diet of leaves, shrubs and grass. A short snout would help with being able to grind leaves and shrubs, longer fingers would help with grabbing branches and a longer toe would help with jumping through these bushes. As the procoptodon started to eat more grass these features changed to help it eat that food source.

100,000 years ago, the woolly mammoth (Mammuthus primigenus) roamed the Earth. The woolly mammoth is one of the most studied megafauna of the Pleistocene epoch, which spanned from 2.6 million to 11,700 years ago. Most populations of it died out around 10,000 years ago [4], although a small population survived until around 3.7 thousand years ago on Wrangel Island [6]. The woolly mammoth was one of the many now-extinct megafauna that existed during the Pleistocene.

Evolution occurs when an animal species develops new bodily structures and functions in order to adapt to their new environment. These developments are seen as positive adaptations that enhances survival. However, some animal species have lost these new developments. Based on the geographic location and climate, some evolutionary developments that are no longer needed are lost due to the fact that the new bodily structure itself does not enhance the chance of survival in a particular environment (Kirchman 2009; Vieites, et al. 2009). In most cases these lost developments are passed down through future generations and are never redeveloped. However, more information is needed to decide whether or not the loss of these evolutionary developments was due to natural selection or by random mutation over years (Wilkens and Strecker 2003). In this paper, I will examine three studies from a diversity of taxa, which illustrate the history of flightless birds, how climate has influenced the evolution of salamanders and how life lived in darkness has influenced the blindness in cave fish. Together these studies depict how these evolutionary abilities are lost and their affects on the animal species.