Factors That Affect The Body Mass Of Adult Female Yellow Bellied Marmots

Marsupials living in Australia’s hot arid environment must deal with exposure to extreme conditions such as high temperatures, solar radiation and limited food and water supply. More than 50% of the world’s marsupial species occur only in Australia (Steffen et al 2009), which indicates their ability to adapt to Australian

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

The Polar Bear (Ursus maritimus) is a bear native largely within the Arctic Circle encircling the Arctic Ocean, its surrounding seas and land masses. Although it is closely related to the Brown Bear, it has evolved to occupy a narrower ecological forte, with many body characteristics adapted for cold temperatures, for moving across snow, ice, and open water, and for hunting the seals which make up most of its diet. Though there are many theories surrounding evolution, the two stand outstanding hypotheses applying to the modification from Brown Bear to Polar Bear are Lamarck’s theory of Use and Disuse, and Darwin’s theory of Natural Selection. The intention of this paper is to compare these thesis and determine the most appropriate in

Global temperature increases and associated increases in precipitation in northern Nova Scotia will likely have detrimental impacts on already threatened species. The Canadian Lynx population is decreasing quickly due to human hunting for its fur and its habitats being destroyed forcing them to continuously migrate north. They have evolved to thrive in snow cover and cold temperatures with their large snowshoe-like paws and thick fur, which gives them an advantage to capture prey compared to other predators such as coyotes or bobcats ("Threats To Lynx" 2012, Hoving et al. 2003). The lynx is a specialist predator focusing on the snowshoe hare as its primary source of food. The hare and the lynx have a very interconnected population cycle that lasts roughly 10 years (Yan et al. 2013). Hares experience large fluctuations in their population cycle based on a number of factors that influence the ecosystem. When hare populations are in decline, in periods where nature must regenerate, the lynx population is also shown to decrease, and vice versa with an approximate two year lag period for the lynx (("Lynx-Snowshoe Hare Cycle | Environment And Natural

The cottontail rabbit, or Sylvilagus floridanus, is one of the most common mammals in North America. Largely known for terrorizing gardens and melting children’s hearts, this animal is considered a pest among some and a harmless critter among others. The cottontail is known for its tall ears, powerful hind legs, and of course, its trademark cotton white tail. Its fur will come in all shades of gray and brown, and it can grow to be up to three and a half pounds. I am proposing a twenty-year study of the cottontail rabbit to learn how different impacts on the rabbits’ world will affect their natural selection process.

“Penguin responses to climate change in the Southern Ocean” by Jaume Forcada and Philip N. Trathan (2009) was a study conducted to analyze and predict the migrating patterns of different species of penguins due to changes in climate. (p. 1618) Also, Forcada and Trathan investigate whether or not certain species of penguins possess phenotypic plasticity (the ability of an organism to change its phenotype in response to changes in the environment) (p. 1618).

Environmental changes due to our climate warming is causing terrible effects on the Marten population in the northern reaches of Wisconsin. What climate change is doing to the habit in which the Marten is living in is changing the amount of snowfall the regions in which the Martens are living in are acquiring. Looking at figure 3 you can see that the total snowfall in the two regions where Martens were reintroduced showed significantly less snowfall accumulation in present day compared to the 1980’s. This is extremely important to note because this change in snowfall can deteriorate the critical zone called the subnivium. The subnivium is the seasonal microenvironment underneath the snow (Pauli et al., 2013). This is a small zone where plants and small mammals thrive during the winter. It should be stated that the subnivium insulates the ground creating a pocket of warmth that allows these organisms to survive the harsh Wisconsin winters. The way a subnivium is formed is based on snow duration, density and depth (Pauli et al., 2013). But this is where climate change comes into play. It is causing snowfall to decrease, the time snow is present is decreased and the density of the snow is lower (Pauli et al., 2013). Having these three factor decline is getting rid of the refuge of the subnivium and killing organisms that thrive there. One such organism is the American Marten. These mammals are small enough to crawl down tree trunks where the snow is melted to gain access to the subnivium. This is where the Marten hunts mice and other small mammals to its heart's content. But with the loss of the subnivium Martens can’t hunt in their little paradise. They will have to find other places to hunt and find prey to satisfy their caloric needs. This is where the Fisher has the advantage, since they are too large to access the subnivium. The Fisher

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.

We have noticed a change in the population of brown and gray deer mice due to a drought. The environmental changes(the drought) had benefited the brown mice, but not the gray mice. The gray mice's population has dropped because camouflage is not suitable in their environment. Here are the recorded results prior to the drought:

After completing my major of Environmental Sciences at the University of Notre Dame, I would like to attend graduate school and continue to research mammals in the field. Though I am not completely certain, I may seek to become a professor to teach others that share my passion for conservation of the environment and wildlife, or work for an environmental agency. To become an agent of change in this field, I would like to focus my research on studying the effects of climate change on mammals. Accordingly, I want to aid in preserving these species, especially those that are endangered, to further promote biodiversity conservation.

The results show that under selection factors and environmental differences natural selection determines which allele should become more common. In the control simulation the frequency of white alleles to brown alleles, once this mutation was added, was about the same amount. It was almost half white and half brown. In simulation two the environment was an equatorial climate such as a forest and wolves were used as the predatory influence. Once the predatory factor was introduced it can be seen that the alleles of white fur decreased and at the end of the simulation the allele was almost lost. Thus, brown fur alleles were naturally selected in the equatorial environment. The fur color blends in with the environment helping them become harder to find by predators. Whereas, for the white bunnies their phenotype stood out in an equatorial environment causing them to be caught easily. Hence, it can be said that the brown fur alleles had a higher fitness which is why their occurrence was greater and that the white allele was less fit leading to less offspring being produced. Consequently, this supports my hypothesis that the brown fur allele would have a higher frequency in the equatorial environment.

In the case of ring species, natural selection and sexual selection each play a role in the divergence of ring species. Selective pressures allowed one phenotype to survive better than others in a certain area; sexual selection could cause divergence because organisms choose mates based on phenotypes. In the case of salamanders, natural selection affected divergence because organisms with certain coloration survived better in coastal or inland environments. In warblers, sexual selection and natural selection seem to play a part in the divergence of the ring species, as forest density and migration distance is variable and affects survival of the species. Molecular and morphological evidence can be used to support multiple species by showing

The article “Study Says Climate Change Influenced Canine Evolution” by David deMar addresses the big idea of the process of evolution driving the diversity and unity of life. The reason why this article addresses big idea one is because the article’s main purpose is to inform the public about the role the climate change has played in shaping Canine life today and to explain how canine evolved over the years from adaptation and survival needs. Along with this the article hopes to use the knowledge gained by this research to explain how other organisms have evolved similarly to climate change. “Study Says Climate Change Influenced Canine Evolution” is about how the research published by professor Christine Janis and others claims that the evolution

"We call them dumb animals, and so they are, for they cannot tell us how they feel, but they do not suffer less because they have no words” (Anna Sewell). There is undeniable evidence that animals are being affected by climate change. Even though the effects are difficult to measure, there are many different ways animals are being affected. With the loss of predator and prey species it affects the life cycles in the food chain. The earth’s climate change causes habitats such as snow, ice, or forest areas to alter, resulting in loss of habitat and food accessibility as well as causing extinction.

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.