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EvolutionAdaptationsClassworkExplain how the LUCA principle helps to explain the universal nature of the genetic code.What is an adaptation?Explain how competition can help drive the process of evolution.Suppose you are studying a population of bacteria in a lab. Some of the bacteria are born with a mutation that provides them resistance to antibiotics. Explain how competition in this population can lead to evolution and make a prediction of how this evolution will occur.HomeworkPick an animal and provide an example of an adaptation that makes it more fit for its environment.Explain why competition exists between individuals in a population, or between individuals of different species.Explain the relationship between the genetic code and the origin of evolutionary adaptations.Theories of EvolutionClassworkExplain the error in Lamarck’s theory of Inheritance of Acquired Characteristics.What is epigenetics?Explain why the Galapagos Islands proved to be an integral part of Darwin’s voyage.What distinguishing feature exists between finches of the Galapagos Islands? What environmental factor creates these differences?Suppose you are studying big cats around the world. How can you use their physical structures to study evolutionary relationships? What is the term for this process?Using Darwinian terminology, explain why a bird would possess wings that are too small to allow it to fly.Explain why, at one point in our embryonic development, human beings have gill slits.According to Darwin’s theory of natural selection, what will happen to the frequency of an allele that allows an organism to successfully compete for resources in a population?Why is rRNA an especially useful tool when analyzing evolutionary relationships between organisms?‘Modern Synthesis’ combines the original work of what two revolutionary scientists?HomeworkExplain how epigenetics proves that at least some of Lamarck’s theory was accurate.Pick one of the organisms Darwin studied in the Galapagos and explain how it helped him to develop his theory of evolution.How is comparative anatomy useful in determining evolutionary relationships?What is the evolutionary term used to describe the similarity between the structure of a bat wing and a human arm? How is this used to explain evolution?Provide an example of a vestigial structure in the human body. Explain, evolutionarily, why this structure exists.Explain, in evolutionary terms, why a fish, pig, chicken and human are virtually indistinguishable during their early developmental stages? What is the study of this process called?Scientists during Darwin’s era discovered that the Earth was many millions of years old (not a few thousand, as previously though) and that the Earth is constantly changing. How did this influence the development of Darwin’s theory?Briefly summarize the theory of natural selection.What role might fossils have played in the development of Darwin’s theory?Suppose humans share roughly 98% of our DNA with chimpanzees, 92% with mice and 44% with fruit flies. How would you use this information to help determine evolutionary relationships?Natural Selection and SpeciationClassworkWhat is speciation?Which traits in an environment would tend to be favored in stabilizing selection?Would more diversity exist in an environment that favors directional selection or disruptive selection?Suppose two species of plants are physically capable of interbreeding and their gametes are compatible, yet interbreeding cannot occur. Suggest a hypothesis for how this situation could arise.HomeworkWhat is the difference between directional selection and stabilizing selection?Explain how the process of behavioral isolation can lead to speciation.What is temporal isolation?Suppose you are working as a caretaker at a zoo that has successfully bred a zebra with a giraffe, but the offspring itself is unable to reproduce. Provide an explanation to zookeepers to potentially explain this scenario.Suppose you are studying two populations of foxes that are of the same species, but have become geographically isolated due to deforestation. Over a decade, you suspect that the two populations may have evolved into separate species. Explain how you could determine whether this is true.Population GeneticsClassworkIs a group of sparrows and blue jays living in the same forest an example of a population? Why or why not?Scientists often refer to a population that exhibits a high level of genetic variability as being ‘elastic’ or ‘flexible.’ Explain why these terms are used in this context.Can the Hardy-Weinberg Equation be used to analyze multiple populations at one time? Why or why not?Identify three things that using the Hardy-Weinberg Equilibrium Equation can be used to determine about a population.Suppose you are studying a population in which 16% of the individuals are homozygous recessive (bb). Using the Hardy-Weinberg equation, what is the frequency of the recessive allele in the population?Referring to the question above, what is the frequency of heterozygous individuals in the population?Suppose you are studying a population of sunfish in which long dorsal fins (L) are completely dominant over short dorsal fins. You find that the population consists of exactly 30% short finned fish. Calculate the frequency of homozygous dominant individuals in the population.Referring to question above, what is the frequency of the recessive allele in this population?Why is the Hardy-Weinberg Equilibrium model more of a theoretical process than a truly concrete procedure?According to the requirements for Hardy-Weinberg Equilibrium, are humans evolving? Why or why not?HomeworkWhat is the relationship that exists between genetic variability in a population and ability to respond to environmental changes?For what purpose do scientists utilize the Hardy-Weinberg Equation?What is the Hardy-Weinberg Equation?Suppose you are studying a population of squirrels in which gray hair is completely dominant over black hair. The frequency of homozygous dominant individuals in the population is 41%. What is the frequency of the dominant allele in the population?Referring to question #51, what is the frequency of heterozygous individuals in the population?Suppose a population contains 10% homozygous recessive individuals. Using the Hardy-Weinberg equation, what is the frequency of the dominant allele in this population?Identify three of the factors that need to be met in order for the Hardy-Weinberg Equilibrium Equation to be effectively utilized.Utilizing the Hardy-Weinberg equation, how can scientists determine whether or not a population is evolving?Genetic Drift and Patterns of MacroevolutionClassworkWhat is genetic drift?Explain how genetic drift can reduce, or even eliminate variation from a population.Can genetic drift eliminate variation from a population where there was a consistently changing set of environmental conditions? Explain your answer.Suppose you are studying an isolated population of elk in Canada that is under intense hunting pressure. Provide an explanation from a genetic standpoint why strict hunting regulations should be enacted for this area. Be sure to use appropriate vocabulary.What is the ‘Founder Effect?’Explain why it is important that populations maintain a certain degree of genetic diversity.Explain how is it possible that 99% of all species that have ever existed are now extinct.Using the finches of the Galapagos Islands, explain the process of adaptive radiation.Both cacti (North America) and a group of plants called euphorbs (Africa) have developed adaptations for surviving drought-like conditions, but they are not believed to be closely related. Explain how this could possibly occur and the name for the process.In western North America, there is a species of flowering plant that has an exceptionally long, deep flower, as well as a species of moth that has an exceptionally long tongue. Explain how evolutionary theory could likely explain the seemingly coincidental occurrence of these two species.Explain how a rapid environmental change could lead to punctuated equilibrium.HomeworkDoes genetic drift tend to have a more drastic impact on large or small populations? Explain your answer.What effect does a population bottleneck have on the genetic diversity of a population?Explain why a group that has endured a population bottleneck may be more vulnerable to disease in the future.Suppose you are a marine biologist working to repopulate the Atlantic bluefin tuna in the Gulf of Mexico after years of overfishing. Explain why it is important that you choose a genetically diverse group of tuna for your repopulation. If you failed to do this, what situation could possible occur?Using what you know about genetic diversity, explain why consanguineous marriages are frowned upon in most cultures.Explain how population bottleneck and founder effect may contribute to the extinction of a species.Is extinction a natural process? Explain your answer.What role does the environment play in the process of adaptive radiation?Why do you think it is important to study evolution?Suppose you are studying anteaters in Africa. You find that the anteaters have developed uniquely long noses and the ants in the area have developed larger jaws for digging deeper in the hard soil. Explain how the two adaptations could be related.What is the name of the process described in the above question?Free ResponseDarwin gathered evidence to posit his theory of evolution. One category of evidence was comparative anatomy. Within this category he described homologous structures. Respond to the prompts below based upon the evidence of homologous structures.Explain what is meant by homologous structures.3543300349885The image below shows the forearm of a crocodile as well as the forearm of a mouse. What do we learn about organisms from comparing homologous structures such as these?14859003810 the central dogma of biology: “The central dogma of molecular biology states that biological information flows in only one direction, from DNA to RNA to proteins.” Using this as our foundation, explain what we can learn, about evolution, from the fact that organisms from bananas to primates to humans, produce and utilize common polypeptides. (utilize the terms proteins, transcription, translation)Natural selection causes changes in populations. Below is a graph representing one type of selection pressure. Respond to the prompts with this graph, and what it represents, in mind.4351655107950 is the term used for this type of selection?365760015240When does this type of selection occur?Use the peppered moth information provided and the image below to describe how the population changed over time (use the following information: dark colored moths, light colored moths, coal and black soot)center3175466852069215 Hardy-Weinberg equilibrium using population and genetic information to determine the possible evolution of a population. Respond to the following prompts on the basis of the Hardy-Weinberg equilibrium (as shown below): p2 + 2pq + q2 = 1Blondes occur in 36% of a particular self- contained human population. Calculate the frequency of the recessive allele.Calculate the frequency of the dominant allele.Calculate the frequency of the heterozygous genotype.List two of the five conditions that must be met in order for a population to meet the Hardy-Weinberg equilibrium.Evolution Answer KeySince all living things share a common ancestry, it makes sense that the general form of DNA is shared amongst all lifeAn adaptation is an anatomical modification or form of behavior, provided by genes that allows an organism to be more successful in a specific environmentCompetition causes some organisms to live longer and reproduce more successfully than others, thus changing the genetic makeup of a population/speciesThe bacteria that have the mutation will survive longer and reproduce more frequently, whereas those that do not have the mutation will not live as long and pass on their genes. Eventually, all bacteria in the population will be resistant to antibiotics.Many possible answers here- stripes on a zebra, regenerating teeth of a shark, non-retractable claws of a cheetah, opposable thumbs of primates petition exists because the resources needed for survival are finite by nature, therefore causing organisms to compete to secure them.Mutations in the genetic code provide the raw material for adaptations. An organism cannot bear an adaptation unless it is provided in the genetic code.Lamarck postulated that the characteristics that an organism acquires over its lifetime are passed to its offspring. This cannot be true because those characteristics do not exist in the DNA.Epigenetics is the study of hoe environmental factors influence gene expressionThe Galapagos provided an ideal setting for Darwin to develop his theory, because they were a series of islands that provided similar, but unique environments that contained similar, but unique speciesBeak size and shape. Availability of food related to climate.The anatomical similarities that exist between different species may suggest a recent common ancestry. Comparative Anatomy.At one time in the history of the species, the wings were used to fly. However, over time the species experience different environmental pressures, which no longer favored flight. The wings exist as a vestigial structure, hinting at the evolutionary descent of the species.This suggests, as with all vertebrates, that all vertebrates share a common ancestry from a primitive vertebrate that used gills.The allele will increase in a populationrRNA changes very little through the evolutionary time scale, much less than the rate of change seen in DNA Darwin and MendelEpigenetics supports the idea that the environment can have an effect on DNA, though not truly in the way that Lamarck suggestedTortoises on different islands had different shell shapes to allow access to available food sources, finch beaks different from island to island depending on food availability, marine iguanas possessed unique characteristics different from terrestrial iguanas on the mainland, he also studied armadillos, mockingbirds and a variety of other speciesSimilar anatomical features may suggest common ancestry in some casesHomologous structures. While the arm and the wing are used for different purposes in different environments, the structure of both is extremely similar, when regarding the bone structure and arrangement. These similarities suggest common ancestry.Appendix, tailbone. An ancestor of the human race had a tail and used the appendix, but as our species changed based on the environmental requirements, these anatomical features decreased in size and function, becoming vestigialAll of these vertebrates share a common ancestry, which is evidenced in the striking similarities of the embryos in each of these species. Comparative embryology.This expanded time frame allowed for the existence of many extinct species that existed over the course of the development of the Earth. It made Darwin realize that as the Earth has changed slowly over time, the species that lived in the changing environments have had to change with it.Individuals in a population that can secure the best resources will survive the longest and produce the most offspring, thus increasing the occurrence of the genes in the population that made the individuals successful.Darwin looked at fossils that closely resembled living species and realized that as the environment changed, the fossilized species had to change as well, leading to the extant species. He also studied the development of the fossils in subsequent layers of the Earth, allowing him to document the change in species over timeThis would indicate that humans and chimpanzees share a more recent common ancestor than either of these species do with fruit flies. The more similar the DNA is between two organisms, the more likely they are more closely evolutionarily related.Speciation is the process by which new species are createdThe average traitsDisruptiveThis could arise through a variety of circumstances. Perhaps the plants bloom at different times of the year (temporal isolation) or the plants are located in different parts of the world (geographic isolation). Other possibilities exist as well.Directional selection favors an extreme allele in a population, pushing natural selection in a specific direction. Stabilizing selection favors the average allele of a trait, reducing the occurrence of the more extreme traits in a population.Behavioral isolation can prevent previously interbreeding groups from interbreeding, which will eventually lead to the creation of a new speciesTemporal isolation is when two species breed at different times of the year, preventing interbreedingEven though the species can interbreed, their offspring cannot. This is called hybrid infertility, and exists in the crossing of many different species. As a result, the resulting hybrid is not truly considered a species.The easiest way would probably be to cross members from the two populations to see if they could produce viable offspring.No. A population consists only of a single speciesThis means that the population can withstand drastic changes in the environment or diseases because the high level of diversity allows the population to fluctuate genetically without putting it at risk of extinctionNo. The equation is only effective for a single population.phenotypic frequencies, genotypic frequencies, allelic frequencies, number of individuals demonstrating each genotype or phenotype, whether or not population is evolvingb = 40% if q2 = 0.16, then q=0.448% if q= 0.4, then p= 0.6 and 2pq is 2*0.4*0.6 = 0.48LL = 20% if q2 = 0.3 then q = 0.55 and p = 0.45 and p2 = 0.2l = 55%It cannot truly be applied to real populations because of the stipulations that must exist, no immigration or emigration, no mutation, random mating, no natural selection, large populationYes, humans as a whole experience mutations and non-random mating.The more genetic variability, the better the ability to respond to environmental changeTo determine whether or not evolution is occurring in a populationp2 + 2pq + q2 = 164% if p2 = 0.41, then p = 0.6446% if p = 0.64 and q = 0.36 then 2pq = 0.4670% if q2 = 0.1 then q = 0.3 and p = 0.7no immigration or emigration, no mutation, random mating, no natural selection, large populationIf the ratios of p and q change from one generation to another, then evolution is occurringGenetic drift is the changing of the frequency of alleles in a population due to chanceGenetic drift encourages a specific allele to increase in a population, which will eliminate variation over timeNot likely. As environmental conditions fluctuate, it decreases the chances that one particular allele will dominate in a population, and instead would select for variation through the gene pool as conditions changeThe more the population is reduced, the more the gene pool is reduced. As you reduce the gene pool of a population, you decrease variability, thus decreasing the ability of the population to withstand environmental pressures in the future and increasing the likelihood of total population lossWhen a small group of individuals relocates and begins a new population, this can create unique genetic scenarios, as some times rare alleles may proliferate in the new population if they were carried by the original founders but were not as common in the larger populationGenetic diversity allows populations to respond to changes in the environment, whereas a population that lacks diversity may experience severe population decline due to sometimes even slight environmental changesLife originated about 3.5 billion years ago. Since the Earth has been through many different large scale environmental changes over this time, species have been created and eliminated continuously for billions of yearsAdaptive radiation involves the creation of numerous species from one common ancestor as a result of many environmental changes. Since the finches of the Galapagos initially migrated from one location, the differing environments on each of the islands cause the creation of many new species from one initial ancestorThis is convergent evolution. Similar environmental conditions favor similar adaptations, but it is the environment, not common ancestry, that initiates these features.This is coevolution. The species evolve in continuity with each other. Often times this represents a symbiotic relationship, where both species directly interact with each other and therefore directly influence the evolutionary trends seen in each species. The moth feeds on the nectar of the flower, and the plant is pollinated by the moth.Punctuated equilibrium is rapid change followed by long periods of little/no change. A rapid environmental change would stimulate rapid evolutionary change, which, if the environment stabilizes, could be followed by a long period of no change.Small populations. Large populations are less likely to be affected by random selection trends, whereas a small population could simply because of the lack of abundance.It greatly reduces the genetic diversityThe population bottleneck results in a very small remnant of a once much larger population. This remnant is less likely to possess the same genetic diversity, and is thus more likely to negatively affected by disease.If you do not use a genetically diverse group to repopulate, the new population will have a lack of diversity and could suffer from a Founder’s Effect type scenario.Consanguineous marriages are more likely to concentrate rare genes in the offspring they produce, and these rare genes may result in rare disorders. Opening marriages to a broader group of individuals will reduce the chances of two rare recessive alleles being inherited by offspring.Population bottleneck and founder effect both reduce genetic variability, which make species less resistant to change and more likely to go extinct as a result of rapid environmental changeYes. As the Earth changes and environments change, the traits that once made a species successful in a particular environment will no longer be favorable. As these now unfavorable genes accumulate, a species is more likely to go extinct. Extinction can be viewed as unnatural when human related changes to the environment cause a species to become unfit and go extinct.The environment causes adaptive radiation, as different environments cause individuals of a species to develop unique traits to fit their new environmental conditions.Answers may vary here. To study the history of life on Earth, to discover the origin of the human race, to gain clues as to how we affect the world around us, to determine how the Earth has changed over time and predict how it may change in the futureThis may be coevolution. The ants and anteaters share a habitat, the anteaters continue to develop longer noses to reach the bottom of the anthills and the ants develop the ability to dig deeper to avoid predation from the anteater. Each species drives the evolution of the other.CoevolutionEvidence for EvolutionHomologous structures are structures in different organisms that are similar because they were inherited from a common ancestor that also had that character.This is one indication that, because they share the same bone structures that are derived similarly, they have evolved over time, through adaptations, from the same common ancestor.If diverse organisms share common polypeptides (proteins) this signifies great similarities in RNA and DNA. This dependent upon the fact that proteins are produced based upon the information translated and transcribed from DNA. If the DNA between diverse organisms is similar, (some greatly similar and some less so), then at some point in the past, these organisms shared DNA. If the organisms shared DNA, then they must arise from a common ancestor.Selectiondirectional selectionWhen one of the “extreme” traits results in the “best fit” for an organism in its environment. dark colored moths and light colored moths were both traits found within the original population; environmental conditions changed due to increased burning of coal; tree trunks became darker due to the build up of black soot; light colored moths became more visible to predators and therefore, did not survive to reproduce as well as the dark colored moths.Population graph shifted with a much higher number of black moths in the population than white moths.Hardy-Weinberg0.60.40.48All five conditions are: Extremely large populations; No gene flow; No mutations; Random mating; No natural selection ................
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