Directional Selection And Disruptive Selection

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.

1. Compare and contrast directional selection and disruptive selection and provide an example of each.

Both directional and disruptive selection is a type of natural selection. Natural selection is the differential survival and/or reproduction of organisms as a function of their physical attributes. (phenotype) This results in evolution over many generations. Each mode of selection alters the mean or variance of a phenotypic trait in a population or species. These distributions can be represented in bell curves. Both selection processes can be influenced by human interaction.

Natural selection is the process by which organisms better adapted to their environment survive and produce more offspring. It’s believed to be the main process that brings about evolution. Natural selection will over time remove the deleterious gene as they have a negative effect for the population and are therefore not going to survive or produce offspring.

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.

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

Predatory selection demonstrated heavily on how the predators prefered brighter males and how females then resorted to whatever was left. From my data of mostly drab and mostly bright guppies with the simulation having 30 rivulus, 30 acara, and 30 cichlids, I could see a clear trend. For the mostly drab guppies, in a mere 7 generations or 141 weeks, showed that the predators had wiped out the brighter guppies having a split demographic of 0% of the brightest and bright guppies, 30% for drab guppies and 70% for the drabbest of guppies. In the mostly bright guppy test, it was more even but showed an obvious lean towards the drabber guppies having 20% and 17% for brightest and bright guppies, and 17% and 46% for the drab and drabbest guppies respectively. With all this data, the trend leaned towards having the bright guppies

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.

In topic 1, the introduction to human uniqueness and social coercion theory, we are introduced to some of the common misinterpretation behind Charles’ Darwin’s theory of evolution, specifically in regards to natural selection and survival of the fittest. One of the biggest contributors to this issue is the lack of exposure to the general public on the overall theory behind these two processes. Instead of a full detailed explanation about natural selection and survival of the fittest, we are just told that it is slow and that to be fit means a level of superiority among competition, respectively. Topic 1 revealed that this is not true, as well as stating that natural selection is about individual risk, benefit and cost is of the utmost importance(Bingham). Based on this newly found insight from the course, how does individual risk, benefit, and cost play such an important role in natural selection even though selection is seen in a population and not a

The evolutionary advantage theory proposes that symmetric individuals are attractive because they are particularly healthy, and the perceptual bias theory proposes that symmetric individuals are attractive because the human visual system can process symmetric stimuli of any kind more easily than it can process asymmetric

Anthropologists are continuously exploring the far corners of the world in search of answers to how everything came to be and the process by which we as humans appeared on this planet. This is a difficult task and therefore, there are many branches of anthropology which strive to discern the pieces of the puzzle from different perspectives and approaches. Through the implementation of the scientific method, anthropologists have tested numerous hypotheses to create theories like the Theory of Evolution. First documented by Darwin, natural selection, the process by which a more fit individual survives and passes on their adaptive traits, has been discovered to play a crucial role in the evolution of

Natural selection is the evolutionary process by which heritable traits that best enables organisms to survive and reproduce in a particular environment are passed to ensuing generations. Organism within the same species may develop new characteristics based on their environment to ensure their survival. The new genetic development within the species maybe then passed on to their offspring. Those within the species that do not develop a new characteristic to adapt to the altering environment are left prone to disease, deformities, and even death or extinction.

Natural Selection- Natural selection is the way organisms adapt over time so that they have the best chance of survival in their environment. Natural selections selects against unfavorable traits, so that the ones that will be of the most evolutionary help will be more common. There are three different way that natural selection occurs; directional selection, stabilizing selection, and disruptive selection. Directional selection is "a favored trait is at the extreme expression of traits," (Kobari). Stabilizing selection is the "selection against extreme expression of traits" (Kobari). Disruptive selection is when

Though the Theory of Natural Selection holds that organisms evolve over time, gradually becoming more complex and better adapted to their environments, it does not specifically address the mechanisms by which evolution happens. The question of how evolution happens begins with Gregor Mendel, who was a monk living in what is today the Czech Republic. Mendel conducted experiments with Pea plants, establishing that there seemed to be some sort of mechanism which was controlling the physical characteristics which offspring of the pea’s displayed. Mendel came to this conclusion by noting that when he crossed peas which displayed specific characteristics, such as flower color, with plants which exhibited the same characteristic that the offspring

In this experiment you will be examining the effect of a dominant mutation that changes how the organism obtains food.