Biology: Evolution & Natural Selection Chapter Exam Instructions. Choose your answers to the questions and click 'Next' to see the next set of questions.

1. Biology Study Guide Pdf
2. Definition Natural Selection Biology
3. Biology 10.3 Theory Of Natural Selection Study Guide Answers

INTRODUCTORY NOTES 1. What is Organismic Biology (what are some of the sub disciplines of study), and how does it compare with molecular or cell biology? Molecular Biology: Focus on DNA structure and the cell itself narrow Organismic Biology: Focus on the individual and biology, molecular biology, evolution, structure, functions, anatomy, physiology, ecology, and classification broad EVOLUTION AND NATURAL SELECTION 1. Explain how is it possible that each species has the reproductive potential to spread over the earth, and yet populations remain more or less stable for most species? Birth Rate vs.

Death Rate A. Saturating the environment with offspring allows what to occur (think mortality)? The more offspring you have the more chance of survival of your offspring, therefore more survival of your species. Saturation = Survival B. Is survival of offspring random? If not explain.

It is both random and dependent on the traits inherited. Random because there can be an unplanned natural disaster that can wipe a species clean. And it is dependent on inherited traits because it could be their inherited traits that keep them alive.

What is the mechanism of evolution? Natural Selection 3. Define in your own words, natural selection, using 'environment' and 'inherited traits' in your answer. Natural Selection: When the environment interacts with your inherited traits so that you can adapt to your environment and survive. What is the end product of natural selection? Evolutionary Adaptation 5. How does natural selection differ from artificial selection, and give an example of the latter.

Natural Selection: Heritable traits that make it more likely for an organism to survive and successfully reproduce become more common in a population over successive generations. Artificial Selection: Describes intentional breeding for certain traits, or combination of traits Mustard crops, pigeons, & flies a. What is actually being 'selected' (for or against)? Traits for a species for artificial selection 6. If predatory frogs found flies with high bristle numbers unpalatable (not edible), what would happen (indicate on the figure)? The number of flies with high bristle numbers would survive and reproduce more and the number would 1 rise.

What unit actually evolves (i.e., is it the individual, the population, the species), and why this is the case? The population (species) evolves, NOT the individual. Because the individual has a higher gene frequency 8. Present evidence for evolution, using insecticide resistance, HIV drug resistance, and antibiotic resistance.

Interpret fig. Under point 6C.

Evolution of a species leads to evolutionary adaptation, so in each case the species was adapting to the pesticide, Drug and antibiotic leading to their survival and reproduction of their species. Resistance leads to survival. Define homology and give an example of how homology presents evidence for the process of evolution. Interpret fig. Under point 6D.

Homology: Similarity resulting from a common ancestry. Same basic skeletal elements are present Human – Cat –Whale –Bat 10. What are we to conclude about vestigial organs (why would nonfunctional organs still be present), and give 2-3 examples of vestigial organs or eyes. Vestigial Organs: Organs that we have; yet have no use Once served to be use but no longer Not enough time has passed; therefore the organs that we do not utilize are still present. Wisdom teeth & appendix Tailbone in humans Hindfeet in whales Endemic Cave spiders Full sighted: entrance; Blind (vestigial eyes): pitch black 11.

Give two characteristic features of island species that strongly suggest that evolution has occurred. Islands have high rates of endemic species 2. Islands are isolated so therefore there is low/no gene flow and speciation A. Relate this to the recent news finding of 30 new species of insects in Sierra Nevada caves. They were secluded and new species formed –Sympatric Speciation 12. Interpret the figure given on slide 15 (percent of amino acids.).

Molecular Homology: Genetic code and protein composition reflects comparative anatomy Humans are mostly closely related to monkeys, whereas not as closely related to lampreys 13. Draw a corresponding cladogram of the 4 Drosophila species in the Hawaiian islands (fig. Under point 6E), and then indicate where the mainland (colonizing) species would be on such a cladogram. How does the study of the time progression of fossils support the process of evolution?

Interpret Fig. Under point 6F. The younger the fossil (organism) the closer it is to the surface. As time progresses the surface becomes higher due to the species that have died off; the residue.

Why cannot we consider religious ideas as alternative hypotheses to evolution, in science? Creationism: is not subject to disproof and therefore falls outside the realm of science. The hypothesis must be testable and if it deals with outside forces, those of which we can not control, we can not test those ideas. EVOLUTION OF POPULATIONS Chapter 21 1.

Biology Study Guide Pdf

What is the so-called 'Hardy-Weinberg' equilibrium (i.e., what is in equilibrium)? The hardy Weinberg equilibrium is when the allele frequencies in a given species remain the same from generation to generation and the characteristics of those species will not change until a mechanism of some sort acts upon it.

Give the Hardy-Weinberg equation, and what each term means. P²+2pq+q² p+q=1 p = Dominant Allele q = Recessive Allele p² = Homozygous dominant (AA) people in a population q² = Homozygous recessive (aa) ones. 2pq = Frequency of heterozygous (Aa) 3.

Derive the frequency of these genotypes: AA, Aa, aA, aa. Also, what is the frequency of the heterozygote? Interpret fig. P = 0.3 q= 0.7 AA = 9% aa = 49% Aa = 21% aA = 21% 4. What are the five assumptions of the Hardy-Weinberg equilibrium? Mating is Random Large population size No Gene flow No Mutation No Natural Selection 3 5. Are the assumptions in (5) reasonable ones for natural populations?

If not, then why is Hardy-Weinberg a useful tool? Populations in nature NEVER meet the stringent conditions necessary to maintain them at H-W equilibrium H-W describes the non-evolving populations giving us a baseline for comparison 6. Using allele frequency, how can we present a functional (working) definition of evolution such that it can be measured in our lifetime? Evolution is described as the change in a population’s allele frequency 7. Define point mutation, gene duplications, and sexual recombination, and then compare the fate of a mutation in a somatic vs. A germ line of cells. Point mutation: When a single base pair has been altered Gene duplications: An extra copy of the gene Sexual recombination: Rearranges alleles into fresh combinations A mutation in a somatic cell is not nearly as harmful as a mutation in a germ line cell gamete Somatic mutation is not transferred to future generation a.

Explain the correlation between generation time and mutation rates. Shorter generation time has higher mutation rates 8. Describe the kind of population that may be most subject to genetic drift? Small & founding populations are subject to genetic drift a. What is Genetic Drift? After point 7b) Change in allele frequency = large changes from one generation to another b. What is the Bottleneck Effect (Fig.

Form of Genetic Drift Environmental Impact Population drastically reduced in size; alleles are lost from the gene pool c. What is the Founder Effect (Fig. Form of Genetic drift Choice of shifting away Changes in allelic frequencies that occur when a small group is separated from a large population and establishes a colony in a new location 9.

About how many experimental trials should be conducted before you trust the results? That is, how many times would you roll the dice or flip a coin before you could predict the outcome of certain results? 2015 johnson 90 hp outboard manual.

As many as possible, more than 25 The chances are usually the same. The ratio is usually unaffected 10. Define gene flow. Gene Flow: The exchange of genetic traits between populations by movement of individuals, gametes, or spores.

It involves the spread of new variants among different populations through dispersal. How does gene flow between two populations affect the distinctiveness of each population? That is, can these 4 two populations undergo speciation when they are regularly exchanging genes? Gene flow present = Less distinctiveness -No speciation Gene flow absent = More distinctiveness -Leads to speciation b. How does this relate to human races - use SE Asia as an example? (Why do we speak of human races and not of human species?) Since the beginning of time, gene flow was not always present therefore gave our species time to adapt to our natural habitats—Therefore leading to different phenotypic traits.

We are ONE species, just different races. What is clinal variation? interpret Fig. After point 9a, mummichog fish Clinal Variation: A gradual change in the traits of a species over a geographical gradient. temperature Mummichog Fish – Different geographical areas, the traits are affected by region because since the water temperature is different they have adapted to different climates.

In the mummichog fish figure, how would you go about determining whether the observed variation in fish cold tolerance is a result of genetic causes or environmental causes (design an experiment and discuss your predictions)? 3 different tanks Common Garden Experiment 13.

What processes actually produce the raw material of genetic variation? Mutation + Sexual reproduction: -Diploidy -Heterozygote advantage (heterosis) -Frequency dependent selection 14. Given that most mutations adversely affect the organism, when do you think a mutation has the greatest chance of positively affecting survival, and why? Mutations are advantageous to a species if they help with the fitness (reproduction) of that particular species.

Certain phenotypical characteristic In times of environmental change 15. In your own words, discuss what this principle means: Genetic variation is preserved by diploidy, heterosis, and frequency-dependent selection. What is diploidy and haploidy, and how does diploidy act to retain recessive alleles? Diploidy: Having two copies (alleles) of each gene.

Haploidy: Cell or organism having a single set of chromosomes Through Heterozygous advantage B. Define heterosis, and how this relates to the fitness of the heterozygote genotype? Heterosis: The tendency of a crossbred organism to have qualities superior to those of either parent 5 Relates to the fitness because the crossbred organism now has the ability to reproduce more and stay fit since it has superior qualities C. How does frequency-dependent selection act to retain rare genotypes? interpret the figure under lecture point 11, on snails Frequency-Dependent Selection: An evolutionary process where the fitness of a phenotype is dependent on its frequency relative to other phenotypes in a given population. As long as the rare snail clone reproduces the genotype will be maintained 16.

What is evolutionary fitness? For an individual to be 'fit', what must it do (i.e., the most important of the four questions mentioned in class)?

You must be able to reproduce. Did you have sex? Did you reproduce? Did you babies survive?

Did your babies reproduce? Discuss the three general types of natural selection understand Figs. 21.13, 21.13, 21.15 Stabilizing: Favors the normal, the common, average traits in a population -The largest number is in the middle Directional: Favors those individuals who have extreme variations in traits within a population -Going in one direction Diversifying/ Disruptive: Occurs when a selection favors the extreme trait values over the intermediate trait values.Split into two directions 18.

Sketch a diagram that conveys the meaning, 'asexual reproduction has a 2x advantage over sexual reproduction' (Fig. Under lecture point 14).

What is meant by 'the cost of sex'? And what features of sexual reproduction are costly compared to asexual organisms? Think in terms of gametes, mating rituals/floral displays, raising offspring The cost of sex = Metabolic Cost: CALORIES Sexual Reproduction you have the male that competes and the female that chooses 6 Raising kids cost money. What are the three chief advantages, evolutionarily, of sexual reproduction? Genetic variation is generated 2. Production of dispersal (species movement away from existing populations; such as parents) 3.

Ability to respond to parasitic pressures A. Which may be of most importance? Ability to respond to parasitic pressures 21. Looking back at the figure about the snails, discuss how frequency-dependent selection relates to the Red Queen Hypothesis (I want you to see the “tie-in”). Frequency dependent selection: Evolutionary process where the fitness of a phenotype is dependent on its frequency relative to other phenotypes in a given population. Red Queen states—Clonally reproducing organism is a “sitting target” The organism is not changing hence is a sitting target 22.

Define sexual selection and interpret Figs. 21.16 and 21.17, discussing how the female of a species “selects” a male without making a conscious “decision”. Sexual Selection: Promotes traits that will increase an organism's success in mating and ensuring that its gametes are successful in fertilization. The bird picture: Female was attracted to the color of the bill Red bill triggered immune response 23. There are limits to evolutionary change.

Discuss historical constraints and tradeoffs. Tradeoffs constrain evolution Adaptation must off set the metabolic cost of the adaptation A. Are all products of evolution adaptive (why or why not)? No SPECIATION 1. Define 'speciation' in words and diagrammatically. Speciation: Biological evolution When a single species is divided due to a geographical barrier; there is no communication between the species so therefore is divided into a new type of species. Define the biological species concept, including an example of a species in which it applies.

Biological Species: When two organisms breed within a species, their genes pass into their combined offspring. As this process is repeated, the genes of different organisms are constantly shuffled around the species gene pool.

The shared gene pool gives the species its identity. Meadowlark Example 7 Explains why the members of a species resemble one another 3. Discuss areas in which the biological species concept breaks down (does not apply well), and why this is the case.

Use in your examples fossils, a clonal organism, and a case of partial reproductive isolation. Fossil species are either dead or extinct a.

Give three large groups of organisms where virtually every species can be clonal. Clonal Organisms: fungi, prokaryotes, plants Partial Reproduction isolation: Salamanders in the Sierra Nevada, Oregon, & California b. As a scientist studying a group of clonal populations of fungi, how are you going to decide how many species you have? By studying the genome and find out which belongs to particular species 4.

Intrepret Figs. 23.5 and 23.6 in terms of allopatric speciation. Allopatric Speciation: Occurs when a population is separated geographically, restricting the gene flow between the subpopulations. Geographic Isolation –Facilitated by geographic barriers & founder effects 23.5 River bed was embedded blocking off communication between two mountains 23.6 Islands of Hawaii separated by water; Numbers of species on each island & the number of founder effects that have taken place. What is adaptive radiation (Fig. Adaptive Radiation: Formation of many related species from a single common ancestor Sequence of allopatric sequenced events 23.7—High amount of speciation occurring in a short amount of time A.

Interpret the hypothetical sequence of events in the figure following Fig. Explain the figure just before lecture point 3a in terms of incipient speciation.

Recall the example and figure given in class of a 'ring species', in which populations of a salamander were distributed in rough correspondence to the Sierra Nevada range of California and Nevada. Define the problem with respect to defining the species in such a case, i.e., how many species are present, and how does this case present a problem to the biological species concept. The biological species concept cannot be applied to this because not all the species can be interbred 8. Define allopatric, and sympatric. Allopatric: Occurs when a population is separated geographically, restricting the gene flow between the subpopulations.

Sympatric: Does not require large-scale geographic distance to reduce gene flow between parts of a population. Reproductive Isolation 8 A.

Definition Natural Selection Biology

Now, look up from your notes and define them in different words again. Allopatric: Geographically isolated –species are derived Sympatric: No geographical barrier –species derived, not as many B. How does allopatric speciation occur, including the role of geographic barriers? Allopatric Speciation occurs when a population of a certain species migrates to a new land, and does not communicate with the primary species, therefore evolving and adapting to their new surroundings soon evolving into a whole different species. Discuss an example of allopatric speciation among pupfishes (sketch given in class). Their habitat started to shrink to separate isolated areas A.

What is meant by, 'allopatric speciation is facilitated by geographic barriers'? Allopatric speciation is facilitated by geographic barriers meaning the species are isolated in one area due to a river in a canyon or caves (i) What were the barriers in the pupfish example? Their habitat was lost 10. Interpret the figure just before lecture point 4 in terms of a laboratory demonstration of reproductive barriers, incipient speciation, and natural selection.

Reproductive Barriers: Isolation that they were raised in Incipient Speciation: The flies of the same production starch vs. Maltose will reproduce more with their own kind than with opposing productions Natural Selection: Artificial selection 11. Explain what happens during autopolyploidy and allopolyploidy, with reference to the two figures given in lecture. Autopolyploidy: Having more than two sets of chromosomes, derived from the same species, as a result of redoubling Allopolyploidy: Having more than the usual number of chromosomes that results from the interbreeding of different species A. Is polyploidy a rare or common event among plants, and discuss what is meant by 'a new species can be generated in a single or two generations.' Common among plants Produces a new species in one generation due to variance in genome and AA performing different role It accounts for above 80% of all plant species B. Plant species A has 2n=10.

Give the ploidy of the gametes, the ploidy of an unreduced gamete, the ploidy of the zygote formed by a meiotic error that produced a union of unreduced gametes, and the ploidy of the adult new species. Gametes: 5 b. Unreduced: 10 c.

Zygote: 4n = 20 9 d. Why can't the new species exchange genes with the parent species above? Different match up of the ploidy autoploidy D. A student asked why does the F1 hybrid produced through hybridization (in allopolyploidy figure) survive? Can such a plant reproduce sexually normally? Understand the figure of how sympatry and allopatry influence the breeding times of three species of frogs, and how this relates to an example of prezygotic barriers to interbreeding? That is, discuss how selection pressures are likely to be stronger in regions of sympatry.

Gametic reproductive isolation: What prevents sperm and egg from two different species from uniting in a test tube? Give two potential postzygotic barriers to interbreeding of two different populations (think in terms of what happens to the hybrid offspring)? What is a hybrid zone, and interpret fig. Hybrid Zone: A region of reproduction between individuals of different species, usually occurring where the ranges of the species come together. Discuss the possible outcomes from a hybrid zone (figure following 23.14).

Interpret Fig. 23.15, and apply the interpretation to understanding point 8b in lecture (high speciation rates in animalpollinated plants, low speciation rates in wind-pollinated plants). What is the relationship between speciation rates and sexual selection, and how this relates to females making discriminating choices (Fig. Discuss why groups of species with short dispersal distances (e.g., snails) tend to have more species (think in terms of gene flow distances)? Since each species of snails move in shorter distances; they tend to remain closer together. Therefore remain isolated from the other species of snails.

Which, then leads to reproductive isolation Leading to speciation—More species developed 19. Hypothesize how gene flow relates to the evolution of the over 200 human languages on the planet? Gene Migration Happens when the allele frequencies of one population has migrated and integrated with another populations allele frequencies. Relates to the evolution of languages because you had your base languages such as Latin, Arabic, Greek—Words and other languages were derived from these languages, therefore evolving into different “species” for a distinguished set of “species” people PHYLOGENY 1.

What process on earth had the most effect on current patterns of biogeography, extinction, and evolution? Continental Drift 2. Give four phenomena that regularly occur at continental plate boundaries. Earthquakes, volcanoes, oceanic spreading, mountain building, tsunamis A. Are the recurrent earthquakes in California and the eruption of Mt. Helens coincidences? How can you reconcile finding coal on Antarctica (and large fossilized animals)?

Define what Pangaea was, how you pronounce this word, and discuss potential reasons why the formation of Pangaea coincided with a high extinction rate on earth? 25.12 11 Pangea: Supercontinent, formed 250 mya and began to breakup 180 mya. All other things equal, discuss rates of extinction and speciation when (i) continents come together, and (ii) continents separate. The break up of continents led to migration Continents together = sympatric speciation Continents apart = allopatric speciation 4. Discuss how the factors of sea level change, oxygen concentrations, and temperature changes have affected species evolution and extinction on earth. A drop in sea level has affected marine organisms extinction Oxygen concentrations have influenced the evolution of life Temperature changes have affected evolution and diversity a.

What is the primary hypothesis explaining the Permian extinctions? What happened to sea level at this time? What is the principal hypothesis explaining the Cretaceous extinctions, and at least two lines of evidence behind this hypothesis? Iridium fallout may have blocked sun for months or years Crater exists in Mexico; supports this hypothesis a. What happened to sea level at this time? Define phylogeny and taxonomy, and how they relate to each other, if at all.

Phylogeny: The evolutionary history, and is derived from the study of fossils and extant living organisms Taxonomy: Identification and classification of species, and consists of a taxonomic hierarchy -Relate because both deal with the history of organisms A. Beginning with Domain, list the categories of classification proceeding from most inclusive to least inclusive, and ending with species (the taxonomic hierarchy) (Fig. Following point 6 in lecture). Domain: Bacteria; Eukarya; Archaea Kingdom: Animalia Phylum: Chordata Class: Mammalia Order: Carnivora Family: Felidae Genus: Panthera Species: Panthera Pardus B. How does the term/field 'systematics' fit with respect to the two terms above? Under point 8 in lecture, and why systematists think that 'ideally, each taxon should correspond to a monophyletic group.'

Biology 10.3 Theory Of Natural Selection Study Guide Answers

12 Systematics: Combination of taxonomy and phylogeny It is ideal because Systematic’s itself embraces a taxonomy that reflects the evolutionary history of a single group. –Monophyly: All descendents from a SINGLE ancestor. Natural group Common Ancestor SHOULD share features that unite present day.