Evolution Final (Essay Sample)
Introduction to the Activity:
This is the second (written) part of the assessment. By the end of this assessment you will be better able to assess your own knowledge of the material covered in the second half of this course. To successfully answer the questions on this exam the student will need to have read the chapters assigned in Modules 5 – 8 and completed all activities.
Instructions to Learners:
The final exam consists of two components: 25 multiple-choice questions(available under the Assessment area) and 5 short-essay questions. Essay questions are available below. You must complete both components of the exam by 11:55pm at the close of Module 8.
Your instructor will evaluate written responses and provide a final grade within a few days.
Wild turkeys are dramatically sexually dimorphic; domestic turkeys are far less so. Suppose that female wild turkeys chose males on the basis of expensive traits that indicate disease resistance and that artificial selection for rapid weight gain in domestic turkeys destroys female choice. What would you predict about the evolution of disease resistance in domestic turkeys? If we observe that domestic turkeys are less resistant, does that necessarily mean that wild females had been choosing more-resistant males, or are other hypotheses equally plausible? Please include at least one scientific research article to support your response.
The main processes involved in speciation are genetic separation and phenotypic differentiation. Provide a discussion of at least two (2) plausible causes for both.
Deviations from the environment to which we are adapted have been used to explain a large variety of conditions, including sudden infant death syndrome (SIDS), the persistent crying known as colic, lower back pain, drug addiction, and depression. Consult the scientific literature for details on one such condition and then evaluate the quality of evidence for an evolutionary interpretation of the condition. Be sure to provide references.
Sand gobies are a small, shallow-water marine fish in which males construct nests underneath empty mussel shells. Females come and lay eggs in the mussel shell nest, and males then guard the eggs until they hatch. Males fan water over the eggs with their fins while the eggs develop. The more eggs in their nest, and the more those eggs consume oxygen from the surrounding water, the more the male will fan the eggs.
Kai Lindstrom and colleagues were curious about how females choose males. In a first experiment, females were placed in an aquarium from which they could view two males, one of whom had been provided with a small nest (a 6cm wide flowerpot nested within a 10cm wide flowerpot), and the other with a large nest (a 10cm flowerpot). Females were kept (with clear partitions) to the side of the nest so that they could not see the inside of the nest - from their point of view, the nests appeared identical. They could, however, see the male at the nest entrance. In a second experiment, low-oxygen water was piped into one of the nests. Again, the females could not perceive the difference in oxygen level from their location—all they could view from their vantage point was the male at the entrance of the nest.
Two experiments were conducted. After the females had been given ample time to view the males, the small flowerpot was removed (in the first experiment) and the low-oxygen water pipe turned off (in the second experiment). The female was then given access to the entire aquarium and allowed to inspect the inside of the nests for the first time. What she saw was that both males had identical nests—10cm wide flowerpots with normal oxygenation. Yet, in the first experiment, 82% of females first chose the male who initially had the larger nest. In the second experiment, 73% of females first chose the male who initially had low-oxygen water piped into his nest earlier.
What explanation do you have for these results? How were females able to perceive differences in nests that they could not see, and why did they make the choices that they did?
Why do pathogens evolve quickly?
Each answer should be at least one-half page in length
Introduction: Research of sexual selection has been focused on its effect to female turkeys. Variation in male turkeys with regard to resistance to various factors such as parasitic infection may also cause a difference in the reproductive behavior of female turkeys. There are two hypotheses that I have proposed two hypotheses to describe how male turkey's level of resistance might affect the sampling behavior of their female counterparts.
The first hypothesis, less resistant males were chosen by fewer prospects mates due to various factors such as chronic infections that might be imposed by energetic factors that reduce the amount of calories that a female turkey can expect in mate searching. Another optional hypothesis is that male chose their prospective female through recognition of susceptibility or resistance to infections and hence spends more time looking for a male that indicates that he can offer specific genes that are complementary to her genome.
By combining these two good genes would enhance reproduction of strong and resistance offspring regardless of the female susceptibility. I examined the male sampling behavior by the female turkeys with regard to a less resistant wild turkey and compared to resistant turkeys. Female turkeys did not spend more time looking for the less resistant males nor were they likely to solicit during this trial. These out comes give the suggestion that females are usually inclined to more resistant males as prospect mates. This happens because females increase the opportunity to get complementary genes for more resistant offspring as well stated by Ostrom, Gauthier & Gall (2001).Â
The major motive in conservation of high resistant of species in conservation and innovative biology is to examine whether endangered species hold sufficient gene that can maintain effective resistant offspring and also understand effective factors that can contribute to retain genetic variance for disease resistant. The main histocompatibility factor (MHC) is a significant genetic area that is involved in immune responses and it is a gene dense and most polymorphic area in the whole genome of organisms (Kelley, 2005).Using other makers that are outside the highly polymorphic MHC classes of genes and also circumvent challenges that are usually encountered in the process of genotypic research.
Wild turkeys tend to display a more attractive characteristic to impress females. This shows that male t...
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