Directional Selection Vs Disruptive Selection Essay

Some plants and animals have to adapt to the amount of oxygen and visibility underwater. For example, plants have adapted to the amount of sunlight they receive in certain environments, and cattails and water lilies have adapted to be able to survive humid climates. For animals, certain fish like trout have adapted to clear and cool water with a large amount of oxygen. On the other hand, other types of fish, like catfish, are able to survive in an area with a low oxygen level and gloomy visibility. Since otters live on the land surrounding the water, they have adapted to be able to swim to catch their food. Frogs and alligators have adapted to their environment by being able to live on the land after coming from underwater as an egg. Lastly, beavers have adapted to use their teeth to create the dams they live

Over the last several years, evolution has been playing an increasingly important role in determining how various species are evolving. This is because ecology will have an impact on how quickly a particular organism is able to adapt (with: the unique challenges for a particular environment). To determine the effect that this is having requires carefully examining different species over the course of many years. This will be accomplished by comparing these changes on Darwin and Wallace Islands. Once this occurs, is when specific insights will be provided that are highlighting the underlying challenges affecting the development of organisms. This is the point that these transformations will be evident among the various life forms. (Fasolo, 2011, pp. 53 68)

The two different types of selection differ because instead of the subject only going in one direction it will split off and go two different ways. This would be disruptive selection where there is more than one option to select or two distinct groups. For example, if some flowers and their colors. The main colors may be red, pink and white primarily, say that the more dominate color being a pink flower. What happens if we remove the pink flower from the equation? It would cause the flowers to shift toward the dominant color which in this case you might think is the red. However, in this case it is not because between red and white is the least drastic and according to phenotypes would be the color that would be dominate if pink was eliminated as an option in a directional selection there is only one trait and it is always that dominant trait that dictates body of the population. Directional selection is more based of natural selection and survival. Examples would be things such as a giraffe having a long neck to reach high foliage than other animals for survival or a bunny being a color more specific to blending into its surroundings.

fitness does well in its habitat and passes those favorable alleles onto its offspring when it reproduces.

1. What is the direct evidence in support of the theory of natural selection? Include at least four examples. Paleontology shows us that organisms have changed gradually over time, as reflected in the fossil record. Biogeography shows us how new species only arise near very similar species. Similar species share a common time and place. Developmental biology shows us that an organism builds on ancestral features as it develops from a single cell. Genetics shows us that we can group species by similarity of

Directional selection and disruptive selection differ because instead of the subject only going in one direction it will split off and go two different ways for example if some flowers and their colors. The main colors may be red, pink and white primarily, and the more dominate color being a pink flower. But if we remove the pink flower completely from the equation then the flowers will shift toward the dominant white color over the red. In a directional selection there is only one trait and it is always that dominant trait that dictates body of the population. The best example to show this is that in the

Directional selection and disruptive selection have quite a bit in common; however, they also have some contraries. Their biggest likeness is that they are both subcategories of natural selection. Natural selection is the process that results in adaptation of a population to the biotic and abiotic atmospheres. Directional selection takes place when an exaggerated phenotype is favored and the distribution curve alters in that direction. Such a shift can happen when a population is adjusting to a changing environment. Disruptive selection occurs when two or more extreme phenotypes are favored over any other ordinary phenotype. These two selections differ in that directional requires only one extreme phenotype whereas disruptive requires at least two. A prime example of a directional selection, is resistance to antibiotic treatment as well as insecticides. The extensive application of antibiotics and pesticides eventually develops populations of bacteria and insects that have grown resistant to the chemicals. When an antibiotic is employed, some bacteria may survive because they are genetically defiant to the treatment. These particular bacteria are likely to provide such genes for the next generation. As an outcome, the number of bacterial defiance continues to increase. Disruptive selection favors polymorphism, which is the happenings of different forms in a population of the exact same species. With thatstatement made, a classic example of disruptive selection would be that

Natural selection involves the adaptation of a species to better survive in their designated environment. When organisms reproduce, they pass down their DNA to their offspring. For example, a child that is tall is the result of their parent being tall as well. Parents pass down traits to their children. When it comes to survival, some organisms are better at it than others based on the traits that they have acquired. Some organisms can camouflage from predators while members of the same species do not obtain that same trait. With that in mind, the ones that can camouflage will most likely survive in certain environments and they will then pass on that trait when they reproduce. Since these traits are advantageous, they are passed on to more and more offspring through time and it will eventually overcome any original traits that species first started out with. It’s kind of like the current state of sexual misconduct in Hollywood. We have our directors, actors, agents, and so forth. However, as time goes on, some do not survive in the business based on their inherently evil traits and they get weeded out just like some species in the wild. As generations pass, these organisms have then adapted to fit the environment and better survive based on their inherited traits.

Directional selection is one of the types of natural selection. In directional selection, one extreme of a trait in a population experiences pressure against it. This causes a shift in the population’s genetic variance to a trait with less pressure against it. This then results in the population gradually shifting from the pressured extreme trait to the unpressured extreme trait on the other side of the spectrum. Giraffe necks are a familiar example. There was environmental pressure against the giraffes with short necks, because the individuals couldn’t reach as far to feed. Therefore, the variance of neck length shifted towards long necks from short necks. Another example is the evolution of the peppered moth in 18th to 19th century England.

b. Describe the homologus trait of each species, focusing on the differences in structure and function of the trait. Why do these homologus traits exhibit differences between the two species? Make sure your explanation is clear and complete.

The fossil of Tiktaalik confirmed a major prediction of paleontology in that it showed characteristics of both aquatic animals, such as fish, and land animals, such as reptiles and amphibians. While it had fins and scales, it also had a flexible neck, a flat head, and complex bone structure in its fins that correspond with the structure of the legs of terrestrial animals. Thus, it demonstrates the evolutionary transition between aquatic and terrestrial life.

As many people may know, bacteria can be either harmful or helpful. The damage on your body can vary by the harmful bacteria. The damage can be as little as a cough all the way to death depending on the bacteria and amount of it. That is why it is really important to for your doctor to prescribe you medicine when you are sick or coming up with something. The reason any doctor emphasizes the importance of finishing the prescribed bottle of antibiotics relates to all 5 steps for evolution by natural selection. The first step one is over reproduction. All animals have the ability to produce more offspring than can possibly survive. This could be critically dangerous for humans because if the bacteria duplicate numerously then the antibiotics might not even be able to kill all bacteria. Another step

The comparative method tests adaptionist hypotheses, by looking at a variety of species under the same environmental pressures. It is expected that a trait should evolve in distantly related species that are under

Any mutation that would prevent the action of antibiotics, but not at the same time provide a selective advantage to the bacteria, would be one that interfered with the bacteria’s ability to reproduce. If this were to occur, then any selective advantage would be negated by the cell’s inability to take advantage of the diminished competition caused by the death of susceptible bacteria. This would be likely to occur in reaction to an antibiotic that interfered with protein synthesis, since it would also impact on the chain of reactions that occurs in the transformation

Antibiotics was developed to combat bacteria by zero in on the bacteria’s structure. As time goes by bacteria can defeat antibiotics in their natural selection. Natural selection plays an important role in the progression of antibiotic resistance. Most of the bacteria dies when it is exposed to antibiotics they are sensitive to. Therefore, it creates more space and availability of nutrients for the surviving antibiotic-resistant bacteria. Subsequently,