AP BIO unit 7 Exam review

TOPIC 7.1 Introduction to Natural Selection

ENDURING UNDERSTANDING EVO-1 Evolution is characterized by a change in the genetic makeup of a population over time and is supported by multiple lines of evidence. LEARNING OBJECTIVE EVO-1.C Describe the causes of natural selection. ESSENTIAL KNOWLEDGE EVO-1.C.1 Natural selection is a major mechanism of evolution. EVO-1.C.2 According to Darwin's theory of natural selection, competition for limited resources results in differential survival. Individuals with more favorable phenotypes are more likely to survive and produce more offspring, thus passing traits to subsequent generations. LEARNING OBJECTIVE EVO-1.D Explain how natural selection affects populations. ESSENTIAL KNOWLEDGE EVO-1.D.1 Evolutionary fitness is measured by reproductive success. EVO-1.D.2 Biotic and abiotic environments can be more or less stable/fluctuating, and this affects the rate and direction of evolution; different genetic variations can be selected in each generation

TOPIC 7.2 Natural Selection

ENDURING UNDERSTANDING EVO-1 Evolution is characterized by a change in the genetic makeup of a population over time and is supported by multiple lines of evidence. LEARNING OBJECTIVE EVO-1.E Describe the importance of phenotypic variation in a population. ESSENTIAL KNOWLEDGE EVO-1.E.1 Natural selection acts on phenotypic variations in populations. EVO-1.E.2 Environments change and apply selective pressures to populations. EVO-1.E.3 Some phenotypic variations significantly increase or decrease fitness of the organism in particular environments. ILLUSTRATIVE EXAMPLES § Flowering time in relation to global climate change § Peppered moth § Sickle cell anemia § DDT resistance in insects

TOPIC 7.3 Artificial Selection

ENDURING UNDERSTANDING EVO-1 Evolution is characterized by a change in the genetic makeup of a population over time and is supported by multiple lines of evidence. LEARNING OBJECTIVE EVO-1.F Explain how humans can affect diversity within a population. ESSENTIAL KNOWLEDGE EVO-1.F.1 Through artificial selection, humans affect variation in other species. LEARNING OBJECTIVE EVO-1.G Explain the relationship between changes in the environment and evolutionary changes in the population. ESSENTIAL KNOWLEDGE EVO-1.G.1 Convergent evolution occurs when similar selective pressures result in similar phenotypic adaptations in different populations or species.

TOPIC 7.4 Population Genetics

ENDURING UNDERSTANDING EVO-1 Evolution is characterized by a change in the genetic makeup of a population over time and is supported by multiple lines of evidence. LEARNING OBJECTIVE EVO-1.H Explain how random occurrences affect the genetic makeup of a population. ESSENTIAL KNOWLEDGE EVO-1.H.1 Evolution is also driven by random occurrences— a. Mutation is a random process that contributes to evolution. b. Genetic drift is a nonselective process occurring in small populations— Bottlenecks. Founder effect. c. Migration/gene flow can drive evolution. LEARNING OBJECTIVE EVO-1.I Describe the role of random processes in the evolution of specific populations. ESSENTIAL KNOWLEDGE EVO-1.I.1 Reduction of genetic variation within a given population can increase the differences between populations of the same species. LEARNING OBJECTIVE EVO-1.J Describe the change in the genetic makeup of a population over time. ESSENTIAL KNOWLEDGE EVO-1.J.1 Mutation results in genetic variation, which provides phenotypes on which natural selection acts.

TOPIC 7.5 Hardy-Weinberg Equilibrium

ENDURING UNDERSTANDING EVO-1 Evolution is characterized by a change in the genetic makeup of a population over time and is supported by multiple lines of evidence. LEARNING OBJECTIVE EVO-1.K Describe the conditions under which allele and genotype frequencies will change in populations. ESSENTIAL KNOWLEDGE EVO-1.K.1 Hardy-Weinberg is a model for describing and predicting allele frequencies in a nonevolving population. Conditions for a population or an allele to be in Hardy-Weinberg equilibrium are— (1) a large population size, (2) absence of migration, (3) no net mutations, (4) random mating, and (5) absence of selection. These conditions are seldom met, but they provide a valuable null hypothesis. . EVO-1.K.2 Allele frequencies in a population can be calculated from genotype frequencies. **See the Hardy Weinberg Equation on your formula sheet ILLUSTRATIVE EXAMPLE § Graphical analysis of allele frequencies in a population LEARNING OBJECTIVE EVO-1.L Explain the impacts on the population if any of the conditions of Hardy-Weinberg are not met. ESSENTIAL KNOWLEDGE EVO-1.L.1 Changes in allele frequencies provide evidence for the occurrence of evolution in a population. EVO-1.L.2 Small populations are more susceptible to random environmental impact than large populations.

TOPIC 7.6 Evidence of Evolution

ENDURING UNDERSTANDING EVO-1 Evolution is characterized by a change in the genetic makeup of a population over time and is supported by multiple lines of evidence. LEARNING OBJECTIVE EVO-1.M Describe the types of data that provide evidence for evolution. ESSENTIAL KNOWLEDGE EVO-1.M.1 Evolution is supported by scientific evidence from many disciplines (geographical, geological, physical, biochemical, and mathematical data). LEARNING OBJECTIVE EVO-1.N Explain how morphological, biochemical, and geological data provide evidence that organisms have changed over time. ESSENTIAL KNOWLEDGE EVO-1.N.1 Molecular, morphological, and genetic evidence from extant and extinct organisms adds to our understanding of evolution— a. Fossils can be dated by a variety of methods. These include: The age of the rocks where a fossil is found The rate of decay of isotopes including carbon-14 Geographical data b. Morphological homologies, including vestigial structures, represent features shared by common ancestry. EVO-1.N.2 A comparison of DNA nucleotide sequences and/or protein amino acid sequences provides evidence for evolution and common ancestry.

TOPIC 7.7 Common Ancestry

ENDURING UNDERSTANDING EVO-2 Organisms are linked by lines of descent from common ancestry LEARNING OBJECTIVE EVO-2.C Describe structural and functional evidence on cellular and molecular levels that provides evidence for the common ancestry of all eukaryotes. ESSENTIAL KNOWLEDGE EVO-2.C.1 Structural evidence indicates common ancestry of all eukaryotes— a. Membrane-bound organelles b. Linear chromosomes c. Genes that contain introns

TOPIC 7.8 Continuing Evolution

ENDURING UNDERSTANDING EVO-3 Life continues to evolve within a changing environment. LEARNING OBJECTIVE EVO-3.A Explain how evolution is an ongoing process in all living organisms. ESSENTIAL KNOWLEDGE EVO-3.A.1 Populations of organisms continue to evolve. EVO-3.A.2 All species have evolved and continue to evolve— a. Genomic changes over time. b. Continuous change in the fossil record. c. Evolution of resistance to antibiotics, pesticides, herbicides, or chemotherapy drugs. d. Pathogens evolve and cause emergent diseases

TOPIC 7.9 Phylogeny

ENDURING UNDERSTANDING EVO-3 Life continues to evolve within a changing environment. LEARNING OBJECTIVE EVO-3.B Describe the types of evidence that can be used to infer an evolutionary relationship ESSENTIAL KNOWLEDGE EVO-3.B.1 Phylogenetic trees and cladograms show evolutionary relationships among lineages— a. Phylogenetic trees and cladograms both show relationships between lineages, but phylogenetic trees show the amount of change over time calibrated by fossils or a molecular clock. b. Traits that are either gained or lost during evolution can be used to construct phylogenetic trees and cladograms— Shared characters are present in more than one lineage. Shared, derived characters indicate common ancestry and are informative for the construction of phylogenetic trees and cladograms. The out-group represents the lineage that is least closely related to the remainder of the organisms in the phylogenetic tree or cladogram. c. Molecular data typically provide more accurate and reliable evidence than morphological traits in the construction of phylogenetic trees or cladograms. LEARNING OBJECTIVE . EVO-3.C Explain how a phylogenetic tree and/or cladogram can be used to infer evolutionary relatedness. ESSENTIAL KNOWLEDGE EVO-3.C.1 Phylogenetic trees and cladograms can be used to illustrate speciation that has occurred. The nodes on a tree represent the most recent common ancestor of any two groups or lineages. EVO-3.C.2 Phylogenetic trees and cladograms can be constructed from morphological similarities of living or fossil species and from DNA and protein sequence similarities. EVO-3.C.3 Phylogenetic trees and cladograms represent hypotheses and are constantly being revised, based on evidence.

TOPIC 7.10 Speciation

ENDURING UNDERSTANDING EVO-3 Life continues to evolve within a changing environment. LEARNING OBJECTIVE EVO-3.D Describe the conditions under which new species may arise. ESSENTIAL KNOWLEDGE EVO-3.D.1 Speciation may occur when two populations become reproductively isolated from each other. EVO-3.D.2 The biological species concept provides a commonly used definition of species for sexually reproducing organisms. It states that species can be defined as a group capable of interbreeding and exchanging genetic information to produce viable, fertile offspring. LEARNING OBJECTIVE EVO-3.E Describe the rate of evolution and speciation under different ecological conditions. ESSENTIAL KNOWLEDGE EVO-3.E.1 Punctuated equilibrium is when evolution occurs rapidly after a long period of stasis. Gradualism is when evolution occurs slowly over hundreds of thousands or millions of years. EVO-3.E.2 Divergent evolution occurs when adaptation to new habitats results in phenotypic diversification. Speciation rates can be especially rapid during times of adaptive radiation as new habitats become available. LEARNING OBJECTIVE EVO-3.F Explain the processes and mechanisms that drive speciation. ESSENTIAL KNOWLEDGE EVO-3.F.1 Speciation results in diversity of life forms. EVO-3.F.2 Speciation may be sympatric or allopatric. EVO-3.F.3 Various prezygotic and postzygotic mechanisms can maintain reproductive isolation and prevent gene flow between populations. ILLUSTRATIVE EXAMPLES § Hawaiian Drosophila § Caribbean Anolis § Apple maggot Rhagoletis

TOPIC 7.11 Extinction

ENDURING UNDERSTANDING EVO-3 Life continues to evolve within a changing environment. LEARNING OBJECTIVE EVO-3.G Describe factors that lead to the extinction of a population. ESSENTIAL KNOWLEDGE EVO-3.G.1 Extinctions have occurred throughout Earth's history. EVO-3.G.2 Extinction rates can be rapid during times of ecological stress. LEARNING OBJECTIVE EVO-3.H Explain how the risk of extinction is affected by changes in the environment. ESSENTIAL KNOWLEDGE EVO-3.H.1 Human activity can drive changes in ecosystems that cause extinctions. LEARNING OBJECTIVE EVO-3.I Explain species diversity in an ecosystem as a function of speciation and extinction rates. ESSENTIAL KNOWLEDGE EVO-3.I.1 The amount of diversity in an ecosystem can be determined by the rate of speciation and the rate of extinction. LEARNING OBJECTIVE EVO-3.J Explain how extinction can make new environments available for adaptive radiation. ESSENTIAL KNOWLEDGE EVO-3.J.1 Extinction provides newly available niches that can then be exploited by different species.

TOPIC 7.12 Variations in Populations

ENDURING UNDERSTANDING SYI-3 Naturally occurring diversity among and between components within biological systems affects interactions with the environment. LEARNING OBJECTIVE SYI-3.D Explain how the genetic diversity of a species or population affects its ability to withstand environmental pressures. ESSENTIAL KNOWLEDGE SYI-3.D.1 The level of variation in a population affects population dynamics— a. Population ability to respond to changes in the environment is influenced by genetic diversity. Species and populations with little genetic diversity are at risk of decline or extinction. b. Genetically diverse populations are more resilient to environmental perturbation because they are more likely to contain individuals who can withstand the environmental pressure. c. Alleles that are adaptive in one environmental condition may be deleterious in another because of different selective pressures. ILLUSTRATIVE EXAMPLES § California condors § Black-footed ferrets § Prairie chickens § Potato blight § Corn rust § Genetic diversity and selective pressures § Antibiotic resistance in bacteria. (Not all individuals in a diverse population are susceptible to a disease outbreak.)

TOPIC 7.13 Origins of Life on Earth

ENDURING UNDERSTANDING SYI-3 Naturally occurring diversity among and between components within biological systems affects interactions with the environment. LEARNING OBJECTIVE SYI-3.E Describe the scientific evidence that provides support for models of the origin of life on Earth. ESSENTIAL KNOWLEDGE SYI-3.E.1 Several hypotheses about the origin of life on Earth are supported with scientific evidence— a. Geological evidence provides support for models of the origin of life on Earth. Earth formed approximately 4.6 billion years ago (bya). The environment was too hostile for life until 3.9 bya, and the earliest fossil evidence for life dates to 3.5 bya. Taken together, this evidence provides a plausible range of dates when the origin of life could have occurred. b. There are several models about the origin of life on Earth— Primitive Earth provided inorganic precursors from which organic molecules could have been synthesized because of the presence of available free energy and the absence of a significant quantity of atmospheric oxygen (O2). Organic molecules could have been transported to Earth by a meteorite or other celestial event. c. Chemical experiments have shown that it is possible to form complex organic molecules from inorganic molecules in the absence of life— Organic molecules/monomers served as building blocks for the formation of more complex molecules, including amino acids and nucleotides. The joining of these monomers produced polymers with the ability to replicate, store, and transfer information. SYI-3.E.2 The RNA World Hypothesis proposes that RNA could have been the earliest genetic material.

Consider the cladogram below. Which groups can be considered a Clade? Explain why, and why not, for each case.

Group A Group B Group C

Research and briefly describe an actual example of a species that experienced the founder effect.

In the early 1800s a number of individuals migrated to the Tristan da Cunha islands to form a British colony. At least one of the colonists appears to have been a carrier and had a recessive allele for retinitis pigmentosa. Retinitis pigmentosa is a relatively rare disorder where the cells in the retina are lost or break down resulting in loss of sight. Individuals who are homozygous for the allele have the disease. By some estimates, in the 1960s, of the 240 residents in the colony, four had the disorder and at least nine others were carriers. This is much more prevalent than would be expected based on the rarity of retinitis pigmentosa in larger populations.

Where do all BRAND NEW traits come from? For example, a baby born with green skin?

Mutations!!

Each population has natural variations in phenotype. What phenotype would of each pair would allow an organism to best survive each environment? Shady forest: Plant with large leaves or deep roots? Island with swampy marshes: Mammal with webbed feet or thick fur? Snowy tundra: Fox with sharp claws or a long tail?

Shady forest: Plant with large leaves or deep roots? - large leaves What limited resource might this phenotype help the organism get more of? - sunlight How would this differential survival impact the next generation of these organisms? - if the larger leaves help them get more sunlight the fitness will increase and thus more plants with larger leaves will be produced. Island with swampy marshes: Mammal with webbed feet or thick fur? webbed feet What limited resource might this phenotype help the organism get more of? movement through water How would this differential survival impact the next generation of these organisms? If the webbed feet is advantages then the fitness will increase and more animals with webbed feet will be produced Snowy tundra: Fox with sharp claws or a long tail? Sharp claws What limited resource might this phenotype help the organism get more of? traction on icy surfaces How would this differential survival impact the next generation of these organisms? If the claws are beneficial then the next generation will have more animals with claws because it helped increase fitness

Plant species A is stimulated to produce flowers in response to warming weather in the Spring. Plant species B is stimulated to produce flowers when hours of daylight become longer in the Spring. Which species would be most affected by the selective mechanism of Climate Change? Explain your reasoning.

Species A because it is dependent on the temperature to bloom meaning that with global warming the increase in temp would lead to a change in the cycle.

List three examples of sets of organisms that display convergent evolution. What trait do they share?

bats and birds = wings flying squire and sugar glider = wings dolphins and shark = tails/fins/gills

New traits may, or may not, be beneficial. It largely depends on the _______________________

environment

How does migration (gene flow) lead to evolution? Consider the definition of 'evolution'!

gene flow is the transfer of genetic material from one population to another. this widens the genetic pool and allows for more genotypes that allow a variation in phenotypes which leads to evolution

Take a look at Essential Knowledge EVO-1H1. Describe what 'non selective process' means. Provide an example of a selective process and a nonselective process.

non selective means it is a random selection process ex: genetic drift selective process ex: natural selection, selective breeding

Explain what each part of the Hardy Weinburg equation represents:

q2 p2 2pq p q

Artificial Selection - BBC Article about Domesticating Foxes tinyurl.com/hvnjbt9 Describe the difference between attempting to tame a single wild fox, and breeding a population of domestic foxes.

taming a wild fox is breaking the genotype and behavior that it has already learned making it harder to tame while breeding domestic ones would be easier to tame because you are changing their genotype and behavioral upbringing.

Consider two lizards. One lizard lived 5 years, had 25 offspring, and died of old age. The other lizard was eaten by a bird at 3 years old, and had 30 offspring. Which lizard was more fit? Why?

the 1st lizard because it was able to die of old age and reproduce animals that will have similar trait to be fit in their environment

Research and briefly describe an actual example of a species that experienced the bottleneck effect. When did it happen? What caused the bottleneck to happen?

the American bison in the late 1800s. this happened due to American colonization and hunting in which the population reduced to almost nothing until they went extinct.

A farmer uses DDT to kill insects in his field. The first year nearly all of the insects were killed. By the fourth year, however, nearly all of the insects survived the DDT treatment. Explain the process of natural selection in this population of insects. Include these words - mutation, phenotype, variation, resistance, adaptation, and differential survival.

through a genetic variation or mutation there was a few individuals that survived the DDT usage because they were resistant. Because of there variation in there phenotype/genotype they were able to adapt and reproduce and generation that was better equip to survive the DDT.

Give an example of a trait, which is favorable in one environment, but a disadvantage in a different environment.

white fur would be advantages in an winter environment where it allows the animal to blend into its surroundings but would be a disadvantage to an animal in an environment with a dark background.