Role of Natural Selection
Natural selection allows animals to have better adaptations. Such as, responding to predators, changes in climate, and adapting to environmental changes. Natural selection tends to help a species survive longer and produce more offspring than those that do not select naturally. There are also several types of evolution. For example, there is divergent, convergent, and parallel evolution. Divergent evolution is the evolutionary pattern where two species gradually become increasingly different. This type of evolution occurs when closely related species become diverse to new habitats. Convergent evolution takes place when different species begin to share analogous traits because of a shared environment or selection pressures. Parallel evolution occurs when two species evolve independently, maintaining the same level of similarities. This type usually occurs between unrelated species that do not have the same niches in a certain habitat.
"In the early 20th century, scientists widely believed that Emperor Penguins were some kind of evolutionary "missing link" and although this theory has dissolved somewhat since then, they are still thought to have evolved from some of the first and most primitive bird species on the planet,"
The adaptations of Emperor Penguins such as, huddling in groups, the fat layer that keeps them warm, and not touching the ice unless it is necessary, all arose because of the cold temperatures of Antartica. These adaptations were maintained because the current environment allowed the penguins to keep the same adaptations. Without these adaptations, they would not be able to survive. For example, Emperor Penguins stand on their feet and rock back and forth using their tail to keep them upright. Without this, they would become really cold and would soon die. Another example of Emperor Penguins adapting to the environmental changes is huddling up in groups during the cold winters. This adaptation is very crucial because the environment of Antarctica is very harsh and cold. Penguins use this to conserve body heat and keep each other warm. Emperor Penguins also have special feathers that shed off the water in order to get the water off as fast as possible. These feathers don't keep them that warm, so they have adapted to gaining a layer of fat that keeps their temperature at bay. This fat layer protects them more than anything.
"In the early 20th century, scientists widely believed that Emperor Penguins were some kind of evolutionary "missing link" and although this theory has dissolved somewhat since then, they are still thought to have evolved from some of the first and most primitive bird species on the planet,"
The adaptations of Emperor Penguins such as, huddling in groups, the fat layer that keeps them warm, and not touching the ice unless it is necessary, all arose because of the cold temperatures of Antartica. These adaptations were maintained because the current environment allowed the penguins to keep the same adaptations. Without these adaptations, they would not be able to survive. For example, Emperor Penguins stand on their feet and rock back and forth using their tail to keep them upright. Without this, they would become really cold and would soon die. Another example of Emperor Penguins adapting to the environmental changes is huddling up in groups during the cold winters. This adaptation is very crucial because the environment of Antarctica is very harsh and cold. Penguins use this to conserve body heat and keep each other warm. Emperor Penguins also have special feathers that shed off the water in order to get the water off as fast as possible. These feathers don't keep them that warm, so they have adapted to gaining a layer of fat that keeps their temperature at bay. This fat layer protects them more than anything.
Directional Selection in Emperor Penguins
Emperor Penguins have a directional selection. This means that certain traits have died off and now there is a certain trait that is more popular. This is very true in Emperor Penguins. For example, almost every Emperor Penguin has adapted to having a fat layer, feathers, and other mechanisms to help them stay warm in their environment. This is shown in the graph to the left.
Evolutionary Timeline
This evolutionary tree shows the relationship between the population size and the major events that have affected Emperor Penguins.
Summary
Speciation Event:
Specific events, listed on the evolutionary tree above show how the population has increased and decreased over time due to specific events. For example, a decrease in food supply occurred around six million years ago due to a change in climate. When the climate changed, it was hard for species to adapt, therefore Emperor Penguins had a decreased food supply. This event has occurred over time in Antarctica affecting many species that live there, including the Emperor Penguin. Fossils suggest that 36 million years ago, Emperor Penguins lived in a much warmer climate and due to the theory of South America and Austrailia drifting away, the ocean currents isolated Antarctica, cooling the climate significantly causing Emperor Penguins to adapt to the extremely cold temperatures. There is fossilized evidence that shows that Emperor Penguins were not adapted to diving yet, and they were a reddish brown color, suggesting a warmer climate. This is shown in the image to the right. New subspecies A&B: A subspecies of the Emperor Penguin is the King Penguin. These penguins are similar because they are the only penguins that only lay one egg. All other species of penguins lay two eggs. They also don't build nests, which is very common in all other species of penguins. Natural selection favored the Emperor Penguin over the King Penguin because of it's special adaptations. For example, their fat layer allowed the Emperor Penguin, whereas the King Penguin doesn't have the same protection as an Emperor Penguin. New species were created because of the events as well. For example, the Eudyptes chrysolophus is a newly formed species because it's brightly colored feathers served as special adaptations that helped scare away predators. This species was formed around two million years ago when the penguin population started seeing an increase in new and different species. Another species that was created was the Pygoscelis adeliae. This type of penguin thrived around six million years ago because the temperature increased. Their size allowed them to survive the warmer temperatures. These organisms are successful because they have gained new adaptations that allowed them to survive in the current conditions. Natural selection favored them because their adaptations helped them to survive. |
Emperor Penguin 36 million years ago (theory)Eudyptes chrysolophus
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Pygoscelis adeliae