7+Evolution

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==**1. What contribution did the following individuals make to our knowledge of evolution? Linnaeus, Buffon, Malthus, Lamarck, Lyell, Darwin, Mayer // Buffon- suggested that Earth is much older than 6000 years Lamarck- said that life evolves and proposed the inheritance of acquired characteristics (jb) Lyell- wrote the Principles of Geology - earth's geology is changing gradually and the changes are continuing today(jb) Darwin- realize natural selection operating, described evolution and natural selection Malthus- wrote an essay on human population saying that suffering was inescapable consequence of human population potential to grow faster than the rate of food and resource growth Linnaeus- introduced the binomial (2 part) system of naming organisms // **== ==**2. How do Darwin’s theory of natural selection & Lamarck’s inheritance of acquired characteristics differ? // natural selection says that reproduction is unequal, individuals that best meet specific environmental demands have the greatest reproductive success inheritance of acquired characteristics says that by using and not using body parts, an individual may develop certain traits that it passes on to its offspring // **== ==**3. Describe the different types of evidence for evolution. (Fossil, comparative anatomy, comparative embryology, molecular biology, biogeography). Give an example of each //fossil- record testifies that organisms have evolved in historical sequence comparative anatomy- compares body structures of different species. common descent shows that evolution is a remodeling process where ancestral structures that originally function in one way are changed as they take on new functions comparative embryology- compares early stages of development. at certain stage vertebrate embryos look alike. molecular biology- enable to read molecular history of evolution in DNA sequence of organisms biogeography- geographic distribution of species suggest that organisms evolve from common ancestors // **== ==**4. Describe Darwin’s theory of natural selection. //natural selection says that there is different success in reproduction based on their ability to meet specific environmental demands. Those who meet demands better will have greater success therefore favorable traits are represented more and there is a gradual change. More offspring are produced than can possibly survive, their are challenges to survival (selection pressures), organisms differ in inheritable characteristics, the organisms most// well adapted to the current environment will tend to live longer and reproduce more and leave behind more offspring (some of whom may have inherited whatever traits allowed their parents to survive and reproduce more) so the frequency of these alleles in the population will increase over time. (jb) **==

**5. Be able to work Hardy-Weinberg problems.**
==**6. What conditions are assumed by the Hardy-Weinberg equilibrium theory? //~population is very large ~no gene flow (jb) or migration of individuals or gametes into or out of the population ~mutations do not alter gene pool ~mating is random ~all individuals are equal in reproductive success (natural selection doesn't occur) // **== ==**7. What are five potential causes of microevolution? How do these compare with the assumptions for Hardy-Weinberg equilibrium? //genetic drift(bottleneck effect, founder effect), gene flow, mutation, nonrandom mating, different success in reproduction. they oppose those of the Hardy-Weinburg equilibrium// **== ==**8. What are sources of genetic variation? // mutations, independent assortment, crossing over, random fertilization, sexual recombination (includes independent assortment, crossing over, and random fertilization - jb) // **== ==**9. Differentiate between stabilizing, directional, and diversifying selection. // stabilizing- favors intermediate variants, require stable environments (ex. heterozygoyte advantage of sickle cell - jb) directional- shifts the overall make up of the population by going against individuals of one of the phenotypic extremes (ex. short to long necked giraffe - jb) disruptive- occurs when environmental conditions are varied in a way that favors individuals at both extremes //**== ==**10. Why doesn’t evolution produce perfection? <span style="color: rgb(0, 0, 255);">//organisms are limited by historical constraints, adaptions are often compromises, chance and natural selection interact, selection can only edit existing form// **== ==**11. What is the threat from antibiotic resistant bacteria? What is generating antibiotic resistance in bacteria? What is the hygiene hypothesis? //<span style="font-weight: normal; color: rgb(255, 0, 0);">We may no longer be able to fight bacteria in the future because we kill all the unresistant bacteria, leaving all of the antibiotic resistant bacteria room to reproduce. hygiene hypothesis says that our immune systems evolved by being stressed with illness as kids...we now live in such a clean environment in the industrialized world that kids immune systems are not being challenge and are not developing their full potential so the rate of asthma and some other conditions is on the rise - jb //**== ==**12. What is the biological species concept? Is it always applicable? <span style="color: rgb(0, 0, 255);">//the biological species concept defines a species as a population or group of populations whose members have potential to interbreed and produce fertile offspring.// **==

**13. Be able to match reproductive barriers with examples. <span style="color: rgb(0, 0, 255);">//(pg 282-283 and study guide)// **
==**14. Differentiate between allopatric and sympatric speciation. <span style="color: rgb(0, 0, 255);">// allopatric- the initial block to gene flow seems to have been geographic barriers that isolated population sympatric- reproductive isolation develops and new species arise without geographic separation // **== ==**15. Why is speciation on islands (adaptive radiation) so much easier and quick? // Because the vegetation is different among islands and they are separated, the organisms adapt differently and the islands become more diverse. //**== ==**16. Differentiate between gradualism and punctuated equilibrium. <span style="color: rgb(0, 0, 255);"> **//(study guide #6)// **<span style="color: rgb(0, 0, 255);"> //gradualism- differences gradually evolve in populations as they become adapted to local environments and new species evolve gradually from the ancestral population punctuated equilibrium- describe abrupt episodes of speciation punctuating long periods of little change or equilibrium//  **== ==**17. Differentiate between analogous and homologous structure, and between divergent and convergent evolution. // Analogous- similar structured organisms because of similar environments Homologous- differently structured organisms because of different environments Divergent- species' characteristics diverge from each other as a result of different environments Convergent- when species come to resemble each other as a result of similar environments //**==

**20. What advantage does the 3-domain system have over the 5-kingdom system? // A three domain system is better because Archae and Bacteria are very different so they should be separated //**
==**21. How old is the Earth? When did life arise? When did O2 first appear? When did eukaryotes first appear? When did multicellularity first appear? When did animals first appear? Briefly describe Miller’s experiment. How did it demonstrate life on Earth could have originated?**==