LSU BIOL 1202 - Chapter 22: Descent with Modification

Unformatted text preview:

What is Evolution and Adaptation?Pre-Darwinian Theory of EvolutionEvolution by Natural SelectionNatural SelectionMechanisms behind Natural Selection (Figure from pg. 458)Artificial SelectionConcept 22.3Homologous and Analogous StructuresHomologous StructuresVertebrate EmbryosBiochemistry and Molecular BiologyConvergent EvolutionThe Smallest Unit of EvolutionGenetic Variation makes Evolution PossibleMutationSexual RecombinationVariation within a PopulationThe Hardy-Weinberg EquationHardy-Weinberg EquilibriumAllele and Genotype FrequenciesPopulation Genetics and Human HealthConcept 23.3: Natural Selection, Genetic Drift, and Gene Flow can alter allele frequencies in a population.Genetic DriftGene FlowConcept 23.4: Natural Selection is the only mechanism that consistently causes adaptive evolutionEvolutionary FitnessDirectional, Disruptive, and Stabilizing SelectionSexual SelectionThe Preservation of Genetic VariationHeterozygote AdvantageConcept 24.1: The biological species concept emphasizes reproductive isolationThe Biological Species ConceptLimitations of the Biological Species ConceptSpeciationReproductive IsolationConcept 24.2: Speciation can take place with or without geographic separationAllopatric SpeciationSympatric SpeciationPolyploidyOne Mechanism for AllopolyploidyConcept 24.3: Hybrid Zones Provide Opportunities to Study Factors that Cause Reproductive IsolationFusionEarly EarthConditions on Early EarthTestable Hypotheses Explaining the Origin of LifeAlternative HypothesesAbiotic Synthesis of PolymersProtobiontsThe Chicken or the EggPossible Sequence Leading to First ProkaryotesConcept 25.2: The fossil record documents the history of lifeFossils Document the History of LifeDating of FossilsRadiometric DatingConcept 25.3: Key events in life’s history include the origins of single-celled and multi-celled organisms and the colonization of land.What were the earliest organisms like?The First EukaryotesEndosymbiosis and EukaryotesChapter 22: Descent with ModificationWhat is Evolution and Adaptation?- Evolution: two main ideaso Change over time of the genetic composition of a populationo Decent of modern organisms with modification from preexisting organisms- Evolutionary adaptationo Accumulation of inherited characteristics that enhance organisms’ ability to survive in specific environments Organisms have traits that allow them to survive better on average than other individuals in the environment; the adaptations will most likely be passed on to offspringPre-Darwinian Theory of Evolution- Lamarck’s Ideaso Use and disuse—bodies of living organisms are modified through theuse or disuse of partso Inheritance of acquired characteristics—these modifications are inherited by offspringo These ideas turned out to be wrongo Lamarck gave the example of giraffes and their neck length—he said that the lifetime of stretching to reach leaves on trees were passed onto offspring. However, because the giraffes did that, doesn’t mean the traits were passed on because it was something they modified in their lifetimes.Evolution by Natural Selection- Darwin and Wallace developed the theory independently- Charles Darwin—voyage of the Beagleo Darwin took a five-year voyage on the Beagle and overtime developedideas on evolution and how organisms developed. He developed the process of natural selection.- Alfred Russell Wallace—naturalist in Indonesiao Wallace studied birds in Indonesia. By focusing on the traits of bird species he was studying, he also came up with the idea of natural selection.Natural Selection- The unequal survival and reproduction of organisms due to environmental forces, resulting in the preservation of favorable adaptations.o Some organisms have traits that allow them to survive better than other individuals. They then pass these traits onto their offspring.- Process “selects” from what is available in the gene pool. - New characteristics are not created on demand.- Natural selection relies on variability of a population (what is available in thegene pool at the time). It selects from the variability in the gene pool. Mechanisms behind Natural Selection (Figure from pg. 458)- Observationso Individuals in a population vary in their heritable characteristicso Organisms produce more offspring than the environment can support- Inferenceso Individuals that are well suited to their environment tend to leave more offspring than other individualso Over time, favorable traits accumulate in the population.Artificial Selection- Selective breeding of organisms to encourage the occurrence of desirable traits.- Analogous to natural selection- Figure 22.9Concept 22.3- Evolution is supported by an overwhelming amount of scientific evidence.- Figure 22.13o Example of natural selection o Soapberry bugs’ primary food source were vine fruit. Their beak would be inserted to the fruit to draw nutrients from seeds. The beak size was correlated to their feeding success. As they began eating golden rain fruit, their beak size decreased because they didn’t need to penetrate as large of a seed.- Drug resistant viruses are examples of natural selection because the resistantstrands survive and reproduce so that only they are left.Homologous and Analogous Structures- Homologous—structures or other attributes in different species that resemble each other because of common ancestry- Analogous—structures that are similar in function, but not in structure and developmental and evolutionary origin- Figure 22.15o Homologous structures in mammalian forelimbso The underlying bone structure in the examples is the same. They all have a humorous, radius, ulna, carpals, metacarpals, and phalanges. o The examples use the structures in different ways, but have the same structure.- In class exampleo The wings of a dragonfly and bird are not homologous, but analogouso The wing of a dragonfly and flipper of a seal are not homologous or analogouso The flipper of a seal and penguin are homologous and analogouso The flipper of a penguin and wing of a bird are homologous, not analogousHomologous StructuresVertebrate Embryos- All vertebrates share similar developmental genes- Differences arise by some genes being switched on or off at varying times during development.- Figure 22.16Biochemistry and Molecular Biology- DNA is universal genetic material- All life forms use approximately the same 20 amino acids to make proteins- All use ATP as the primary form of cellular energy- All use RNA and


View Full Document

LSU BIOL 1202 - Chapter 22: Descent with Modification

Documents in this Course
Test 3

Test 3

11 pages

Notes

Notes

14 pages

Exam 3

Exam 3

5 pages

Test 2

Test 2

14 pages

EXAM 3

EXAM 3

7 pages

Test 1

Test 1

10 pages

Notes

Notes

25 pages

EXAM 3

EXAM 3

6 pages

Notes

Notes

7 pages

Test 3

Test 3

14 pages

EXAM 4

EXAM 4

8 pages

Exam 2

Exam 2

16 pages

Exam 1

Exam 1

19 pages

Load more
Download Chapter 22: Descent with Modification
Our administrator received your request to download this document. We will send you the file to your email shortly.
Loading Unlocking...
Login

Join to view Chapter 22: Descent with Modification and access 3M+ class-specific study document.

or
We will never post anything without your permission.
Don't have an account?
Sign Up

Join to view Chapter 22: Descent with Modification 2 2 and access 3M+ class-specific study document.

or

By creating an account you agree to our Privacy Policy and Terms Of Use

Already a member?