Evolutionary bio essay for final
Evolutionary bio essay for final

Evolutionary bio essay for final

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  • Pages: 11 (2784 words)
  • Published: January 3, 2018
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Final exam essay questions The optional final exam will consist of five of the following essay questions. Each essay will be worth five points. The final will be averaged with your other four grades. There will be a follow-up post on whether you should take the final exam, but we wanted to get the essay prompts out to you as soon as possible. 1) Two species of Hawaiian ellipsoid, Chaney floorboard and C.

Apocrypha, have diverged from a common ancestor approximately 0. 5 million years ago. No fossil record Is known for these species.

You are trying to determine which species has en evolving at the fastest rate at the molecular or morphological level since they diverged from their common ancestor. Describe the data you would need to collect to make that determination and how you would i

...

nterpret it.

There are two ways to determine whether any species has evolved faster than one another at the molecular or morphological level since their last common ancestors. Since there is no fossil record, there Is no way that one can look at molecular level to see the rate in regard of polypeptide, polypeptide, polysaccharides, enzyme, energy TAP.

The second out is known as the systematic way, in which one is required to look at the phylogeny tree to determine the rate of the growth by looking among related species with the compared organisms to determine the growth. By comparing the homologous structures between species, one can determine how fast the molecular and morphology are changing In how fast the species are changing and gaining the function of the structures. Not sure about this one. I alread

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sold my book back so I can't really look It up.

2) Evolution can be defined as change in allele frequencies over time.

Name three evolutionary processes that can cause evolution in this sense and describe how they do so. Describe how two of those processes might act in opposition to each other. What Is the likely evolutionary outcome of that opposition? Three evolutionary processes that can cause evolution in the change In allele frequencies are artificial selection, experimental evolution and imperfect adaptation. Artificial selection can cause evolution in which human are allowed to select for the allele that caused the desired changes in physiological as well as the behavior that they wanted.

Artificial selection allowed the human to pick out the desired traits that he organisms already have and therefore continue to breed the desired traits In the possibility of having the trait to pass on to the next generation.

Artificial selection allows the human to breed the desired traits and it allows the process of allele frequencies to change. For those traits that the human do not desire, they will less likely to breed it, therefore decrease the frequencies for the allele in the population. Experimental and imperfect adaptation allows the environment changes to occur in which the organisms are forced to adapt to the new environment.

In the uniqueness that the organisms can not adapt to the new environment because of survive and with the changes in the environment over time, there are more likely that nature will select for the trait that help the organisms. Artificial selection and imperfect adaptation may act in opposition with each other, in which the desired

traits may negatively affect the organisms in their lives.

However, nature will be sure to select for the traits that will help the organisms to live (How can you describe the last question)?

There are many evolutionary processes to choose from but, For this one I would hose Natural Selection, Sexual selection, and Genetic Drift. Evolution is driven by a change in allele frequencies over-time, these processes facilitate evolution by adding or removing genetic variation from a population. Natural selection occurs when there are differences in survival and/or gamete production between two phenotypes in the population. One phenotype is selected for by being more successful, thus allele frequencies shift.

Sexual selection occurs when there are differences in mating and/or fertilization success.

When males possess an attractive trait they are chosen for mates by females. This decreases access to the other males without this trait and decreases the chances that they will pass on their traits to offspring. This causes the allele frequency to be driven toward the attractive traits. Genetic drift causes removal of genetic variation in a population due to chance and effects primarily small populations.

Basically, if an event happens in a small population and causes a number of individuals to die then the remaining population may have a different genetic structure by chance. Genetic drift can cause interference with Natural selection.

The reason is that genetic drift acts randomly while Nat. Election doesn't.

This means that in a smaller population, genetic drift acts upon the genotypes frequencies without regard to their phenotypes effects. In contrast, selection favors the spread of alleles whose phenotypes effects increase survival and/or reproduction of their carriers, lowers

the frequencies of alleles that cause unfavorable traits, and ignores those that are neutral. The magnitude of drift is large enough to overwhelm selection when the selection coefficient is less than 1 divided by the effective population size. ) Describe two examples of populations failing to achieve perfect adaptation, from he following course topics: population genetics, molecular evolution, evolution of quantitative traits, life history evolution, kin selection or sexual selection.

Do not use two examples from the same topic. Do not use any examples from lecture 4. Explain why your examples lead to imperfect adaptation. As much as the organisms tried, there is no way that many organisms can achieve perfect adaptation (No organisms can achieve perfect adaptation, it doesn't exist).

For example in the theory of kin selection in which an individual who belongs to the and be able to reproduce the next generation. For an example in the process of Which on is this an example of?? Squirrel, the squirrel was willing to make the call and sacrifice their lives in order to protect their kin. We may not know how fit the martyred squirrel in regard of fitness but the squirrel decided to die in order to protect the weaker, less able to defended squirrel, therefore the strong one was willing to die no matter what.

Therefore, we have no way to know that the squirrel can pass on their perfect gene on to the next generation beside sacrificing its life for others.

In addition, molecular evolution is another example in which nature may how how it fails to achieve perfect adaptation. In the Banishment's fox experiment, experimenters selected for desired genes

and continued to let it reproduce into the next generation, the frequency for the undesired genes will decreased and therefore decrease the phenotype in the future generation.

However, if the environment changes in the future and the undesired gene has better fitness than the previous desired gene, it is more likely that the undesired gene will become the desire one. Therefore, many mechanisms prevent any organisms from achieving perfect adaptation(l think Battles foxes were in lecture 4).

Alternative examples: Imperfect adaptation= Nothing is perfect. Adaptations will be imperfect because of genetic constraints. One example in population genetics ( I guess molecular evolution too? Is Sickle cell anemia- In North America sickle cell is at a disadvantage, but in other areas of the world where Malaria is common so is sickle cell. This is because the heterozygous genotype for sickle cell provides resistance to malaria. BUT, the homozygous genotype is STILL at a disadvantage because they will suffer sickle cell severely. This is imperfect because allele frequencies cannot be controlled and people will still die f malaria or suffer from sickle cell disease.

In sexual selection, a female may be attracted too biological ornament.

An example of this is how in many bird species, females will choose brighter mates because this indicates that they are healthier (parasitic resistance) and better foragers because their bright coloration comes from carotids in their diet. What makes this adaptation imperfect is that because of their brighter color, it makes it harder for them to evade predation. 4) A number of experiments with founder effect have been done in the laboratory, here a small number of individuals is selected randomly from

a large source population to start the next generation.

In some of these experiments, the measured heritability for traits is higher in the founder population than in the original source population. How can you explain this result? How does it relate to founder event speciation? Fact that there is more traits in the founder species in comparison to the original population. The founder population is where the gene pool for the future generation and therefore the future offspring will have will gene that come from this gene group. Therefore, the heritability is really high here.

In original population, there are more traits but the gene pool is bigger, therefore, there are more chances for the offspring to have more traits.

Therefore, as a result, there is lower heritability. Founder event limits the gene pool and as a result, future offspring has gene that come from the gene pool founded by the founders. I think that the measured heritability for certain traits would be higher in the founder effect pop than the original larger population because the founder population is smaller and has suffered a loss of genetic variation. This would be largely due to inbreeding.

Stronger traits would be driven to fixation faster and others lost. 5) Animals use signaling in many contexts, and address signals towards heterocyclic as well as conspiracies of the same and opposite sex. Under what circumstances should honest signals evolve? Under what circumstances should dishonest signals evolve? Be sure that you provide a detailed description of the attributes of sender and receiver that lead to honest versus dishonest signals. You may use examples to illustrate your discussion, but simply giving

an example will not chive any credit.

Honest signals should evolve when there is a (benefit to males even though it is costly to produce) benefit cost requirement for good gene for better adaptation. For example, the female fish who is located in high predation area will prefer to mate with male who is better adapted with good quality gene.

With high predation, female who mate with good male will ensure higher probability of her offspring to survive in the future. Honest signal helps female distinguish which male is a better mate with good gene because honest signal is energy costly.

Dishonest signal (would evolve hen there is a benefit to the signal and it is NOT as costly to produce) should evolve when there is no predation and there is enough population of both sexes to mate in the population and there is no competition for mate. Mate will mate without the constrains of direct benefit as well as indirect benefit. Not 100% sure about this one..

. But I would check out the fish scenario where there is a sneaker fish/ main fish/ then a mimic fish. The main fish has more paternal care, honest signaling and better sperm. The others sperm isn't as good.

But I am not sure as to what would drive evolution in these types of traits... I would think maybe male-male competition? 6) In humans, as in many other species, the geographic region of species origin contains the greatest genetic diversity, with significantly lower diversity in more recently colonized areas.

A similar pattern can be seen the amount of species diversity within a Claude-the region of origin contains the

greatest number of species. Provide a population genetic explanation for either pattern (but not both). Be as comprehensive as possible. Owe human migrated out of Africa and then evolved and therefore changed from there. The other involves how the human race evolves in Africa and then migrate out.

(l really don't know how to explain this one... ) Look up ISOLATION. It is a population bottleneck (founder effect) caused by geographic isolation..

. The only variance added would be from genetic drift (like the Europeans coming over to America, then Africans being brought) etc. When there is a smaller founding population, genetic variation is lost and certain traits may be driven to fixation.

The larger original population of course will have more variation. 7) One consequence of an expanding human population is the fragmentation of there species ranges.

Describe the major consequences of habitat fragmentation in terms of population genetic variation and extinction probability. Contrast the consequences of current habitat fragmentation with the vicariate events that occurred during the Pleistocene-what is different and why? What kinds of species are likely to be most sensitive to the population genetic events that accompany habitat fragmentation? What kinds are likely to be relatively insensitive?

Geographic allows the species to diverse into different species in the ecological and biological speciation. The earth was hypothesized to be a one big land mass and then during the development, they have splinted up into different continents in different areas that we have seen today. Once geographically split, the species are forced to adapt to the environment and they may change their mating preferences. After a long time if the separated species are back

together, they may not be able to mate because they are unable to due to their biological differences, therefore, we will have different species.

Species that are most sensitive to the population genetic events are those that can still mate with one another, one who still have the same dating preferences and they are biological comparable to mate with species and still be able to Just become one species.

They are affected majority because the genetic events will eventually force it to not be able to mate with each other. The species that are insensitive to genetic events are those that ecological, biological and physical unable to mate with one another original.

They are already two different species. If they cannot mate with one another prior, there was no way that this will affect them. I have no idea on this one 8) The creation of phylogeny trees from molecular data has facilitated the study of any questions in evolutionary biology.

Describe one example of how having a phylogeny tree has added to our understanding of either speciation or adaptation (note: for speciation it is not sufficient to simply determine how species are related to each other).

Be sure to compare how this question would be studied in the absence of a robust phylogeny with what is gained by having a phylogeny for the group. By looking at the trees, we can see you species are able to adapt and how species has diverse over time. Through the phylogeny tree, we are able to see the idea of alps us see the trait that is now present, it must have been the fact that the

last common ancestor of the species must have it as well, therefore, as a result, the species that share the trait may be related to one another.

IN addition, analogy which shows the derived trait to show how the organisms may not be related to each other but analogy shows us how an organism may end up acquiring the trait. Phylogeny tree helps us to see adaptation in which we are allowed to see how organisms are evolved over time with specific body design.

Therefore, we are able to learn more about the organisms and how it is fitted to live in its environment. My thoughts are that the molecular phylogeny trees provide info about how closely related we are to another species.. Or example, we are closely related to chimps and chimps to us..

But not so much to the ape. But we are as closely related to ape as the chimp is.. So it wouldn't make sense that our species came from chimps. Rather, our species AND the chimp species both evolved from ape simultaneously. Don't hold me to it.

Lol Sorry not too sure on this one either. I hope this was helpful for you!!!...

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