Introductory Questions #1-(review) 1)Briefly explain the differences between Transformation, Conjugation, and Transduction. How are these three processes the same? (pgs ) 2)How is an F plasmid different from an R plasmid? 3)How are repressible operons different from inducible operons? Give an example of each. 4)What is the difference between an operator and a promoter? 5)Name three example of a virus that has DNA as its genetic material and three examples of Viruses with RNA as its genetic material. (See the table in text) 6)Briefly explain what a vaccine is and what it does. 7)Why are transposons called jumping genes? What purpose do the insertion sequences play? 8)What is the difference between an oncogene and a tumor repressor gene? Inactive Repressor-Lactose Present Examples of Common Viruses DNARNA HerpesvirusEbola PoxvirusInfuenza Papovirus (warts)HIV Measels, Mumps Rabies West Nile Vaccines-Pg. 343 Harmless variants of the pathogen Stimulate the immune system-produce antibodies Smallpox has thought to be eradicated (polio) Rubella, mumps, hepatitis B, other viral diseases Review of Concepts (Ch. 1-20) 1)Give three important properties of water 2)How is an amino acid different from a nucleic acid? 3)Explain how a carbohydrate is different from a lipid? Give three examples of each. 4)How is glycolysis different from the Kreb Cycle? 5)Give three differences between Mitosis and Meiosis 6)Why is cholesterol an important part of a membrane? 7)How can you tell if genes are linked? 8)Name three aneuploidy conditions and three Autosomal recessive disorders we discussed. Review of Concepts (Ch. 1-20) 9)Put these scientists in the proper Historical sequence according to their key discoveries. Generate a timeline labeling each person on it with the date. SumnerMeselson & Stahl MorganPeter Mitchell Garrod Hershey & Chase GriffithSinger & Nicholson Meissner Watson & Crick Frye & Edidin Avery, Macloed, & McCarty McClintock Timeline for Key Figures & Research Meissner (1868) Garrod (1908) Morgan (1910) Sumner (1926) Griffith (1928) Avery, McCloed, & Macarty (1944) Hershey & Chase (1952) Watson & Crick (1953) Meselson & Stahl (1958) Peter Mitchell (1961) Frye & Edidin (1970) Singer & Nicholson (1972) Key Enzymes to Remember Can you determine the process each of the enzymes below are involved with and what it specifically does? Eco R1, Hind III, and BAM IHelicase TelomeraseLactase DNA Polymerase (I,III)SSBPs Aminoacetyl-tRNA synthetaseDNA ligase Cyclin dependent kinase (Cdks)Aldolase Dehydrogenase (name two)Sucrase ATP synthaseMPF Pyruvate kinaseIsomerase Hexokinase Next Unit: Evolution & History of Life- Chapters: Chapter 22: Darwinian View of Evolution Chapter 23: Microevolution &Allele frequency changes in Populations Chapter 24: Macroevolution (Speciation) Chapter 25 & 26: Mapping out the History of Life through systematics & Phylogenic relationships. Introductory Questions #2 1)Why is evolution such a controversial subject? 2)Name the key founders (original people) for the idea evolution. 3)Name four major pieces of evidence that Darwin considered in formulating his theory of natural selection. 4)Name three people that influenced Darwins thinking as he developed his theory. 5)Name the four key observations Darwin made. 6)Why is fossil evidence considered the most direct evidence for evolution? Approximately, how many fossil species have been discovered? 7)What are the three methods for generating a date of a fossil? Chapter 22: Darwinian Evolution (The Beginning) Charles Darwin: -Born in England -Medical School -Clergyman -Naturalist (botany) -Explorer (HMS Beagle) Descent with Modification (Evolution) Evolution: the change over time of the genetic composition of populations Natural selection: populations of organisms can change over the generations if individuals having certain heritable traits leave more offspring than others (differential reproductive success) Evolutionary adaptations: a prevalence of inherited characteristics that enhance organisms survival and reproduction November 24, 1859 Introductory Questions #2 1)Why is evolution such a controversial subject? 2)Name the key founders (original people) for the idea evolution. 3)Name four major pieces of evidence that Darwin considered in formulating his theory of natural selection. 4)Name three people that influenced Darwins thinking as he developed his theory. 5)Name the four key observations Darwin made. 6)Why is fossil evidence considered the most direct evidence for evolution? Approximately, how many fossil species have been discovered? 7)What are the three methods for generating a date of a fossil? Major Issues & Questions about Evolution Our Concept of time is obscure: putting into perspective and grasping the significance of long periods of time such as 100 yrs? 1000yrs? 10,000yrs? Or even a million years. The most difficult concept that Darwin proposed was that all living things are related by a common ancestor. How would respond to this question? When studying life do you include man with all living things or do you separate man? Evolutionary History Linnaeus: taxonomy (binomial Nomenclature) Hutton: gradualism Lamarck: Use & disuse (acquired Charact) Malthus: populations & resources Cuvier: Paleontology (fossils) Lyell: uniformitarianism Darwin: Natural selection Mendel: inheritance Wallace: natural selection Historical Perspectives on Evolution AristotleSpecies are fixed & unchanging LinnaeusFounder of taxonomy (binomial nomenclature) CuvierBegan the study of fossils (Paleontology) Catastrophism Charles Lyell Uniformitarianism-same process occur today HuttonGradualism Erasmus DarwinEnvironment changes causes life to evolve LamarckLaw of use & disuse, inheritance of acquired characteristics HenslowDarwins mentor at Cambridge (Botanist) FitzRoyCaptain of HMS Beagle MalthusPopulations struggle for resources (competition) Wallaceformulated same theory of natural selection Lyell (Geologist)Lyell (Geologist) Earth was ancient & ever- changing Influences on Darwins Theory Malthus (Economist)Malthus (Economist) Survival of the Fittest Political & Philosophical RenaissancePolitical & Philosophical Renaissance Influences on Darwins Theory Video Clip Observations made by Darwin Variations exist in the population (heritable) Reproduce Exponentially (if all are successful) Populations tend to be stable Resources are (become) limited Differential Reproductive success (selection) Artificial selection (breeding) modifies adaptations Noted subtle differences in finches & tortoises, by island & compared to mainlandNoted subtle differences in finches & tortoises, by island & compared to mainland Galapagos Islands Adaptions to Environment Phylogenetic Tree of Darwins Finches Common Ground Finch Examples of Descent with Modification Based on Fossil Evidence Major pieces of Evidence for Evolution Biogeographical Distribution Comparative Anatomy (homologous structures & vestigial organs) Comparative Embryology Fossils Post Darwin: Neo Darwinism also called synthetic theory Molecular Genetics: DNA/Amino acid Sequencing Chromosomal Changes Mutations Evolution evidence: Biogeography Geographical distribution of species Examples: Islands vs. Mainland Australia Continents These organisms evolved independently of each other in similar environments Evolution Evidence: Comparative Anatomy Homologous structures (homology) Descent from a common ancestor Vestigial organs Ex: whale/snake hindlimbs; wings on flightless birds Convergent Evolution due to similar niches-same structures form w/same purposesConvergent Evolution due to similar niches-same structures form w/same purposes Similar characteristics formed from similar environments with different original structures. Structures are used for a similar function **Similar structure different origin Evolution Evidence: Comparative Embryology Pharyngeal pouches, tails as embryos Fossil Evidence Fossils: remains and traces left behind by organisms -most direct evidence for evolution -provides a record of ancient organisms that have existed -able to generate a timeline -observe the presence of vestigial structures -ancestral descent and lineages can be generated -more aquatic fossils vs. terrestrial have been found Types of Fossils: imprints, hair, nails, tissue, and other remains Locations:sedimentary rock, ice, amber, tar, quicksand, petrification Evolution Evidence: The Fossil Record Succession of forms over time Transitional links Vertebrate descent Dating Fossils Location within the rock strata (use index fossil) Radioactive isotopes (half-life) K 40 half life is 1.3 billion years argon U 235 half life is 704 million years lead U 238 half life is 4.5 billion lead C 14 half life is 5730 years nitrogen Extinct Whale w/ small hind limbs Evolution of the Horse Issues/Arguments with Fossil Evidence Record is Incomplete Transitional fossils are lacking Dating techniques are not very accurate (wide ranges) Fossils are difficult to find Conditions must be perfect to form & remain intact Provides evidence of species that existed but are now extinct (ex. dinosaurs) What if fossils were never found? Evolution Evidence of Today & Molecular Biology Similarities in DNA, proteins, genes, and gene products Common genetic code Human Chromosome #2 Human & Chimp Comparison of Chromosome #2 Molecular evidence for common Ancestry Introductory Questions #3 1)What is meant by homoplastic features? 2)Organisms that are from separate ancestries adapt to their environments similarly from similar structures. This is an example of. 3)How many vestigial structures have been observed in humans. Name three of them. 4)Why is biogeography (distribution of species) important evidence for evolution? 5)Why is the chimpanzee considered to be the closest living relative of humans? 6)How is a phylogenetic tree generated and what sort of information does it provide? Key Points to Remember A population evolves, not an individual organism Natural Selection occurs through interactions between individuals Variations in a population are heritable that are not acquired in their lifetime Natural selection is the mechanism of evolution The accumulation of small gradual changes over long periods of time results in larger changes (adaptations) A new species emerges with slightly different characteristics usually because of being isolated. (Galapagos Islands) How and why organisms are able to transmit heritable traits to the next generation was not explained by Darwin. Evolution can only modify existing structures. Final words... Absence of evidence is not evidence of absence. Chapter 23-Microevolution Population genetics Population: a localized group of individuals belonging to the same species Species: a group of populations whose individuals have the potential to interbreed and produce fertile offspring Gene pool: the total aggregate of genes in a population at any one time Population genetics: the study of genetic changes in populations Modern synthesis/neo-Darwinism Individuals are selected, but populations evolve. Hardy-Weinberg Principle Model proposed in 1908 Represents an ideal situation Seldom occurs in nature Mathematical model is used to compare populations Allows biologists to calculate allele frequencies in a population Serves as a model for the genetic structure of a non-evolving population (equilibrium) Represents genetic equilibrium If the allele frequencies deviate from the predicted values of HW then the population is said to be evolving. Hardy-Weinberg Theorem 5 conditions for Equilibrium -Very large population size - No migration - No net mutations - Random mating - No natural selection **when all these are met then a population is not evolving Hardy-Weinberg Equation p=frequency of one allele (A); q=frequency of the other allele (a) p+q=1.0 (p=1-q & q=1-p) P 2 =frequency of AA genotype 2pq=frequency of Aa q 2 =frequency of aa genotype; p 2 + 2pq + q 2 = 1.0 Solving & Analyzing HW Principle Problem: If you had 90 individuals that possessed the recessive condition in a population of 1000 individuals, determine the frequency of dominant and recessive alleles present in the population as well as the genotypic and phenotypic frequencies. (1)Always start with the # of homozygous recessive alleles - aa = 90 and q 2 = 90/1000 which is a = square root of 0.09 which is A = (1 0.3) which is AA = (0.7) 2 which is Aa = ??? **Remember that p 2 + 2pq + q 2 = 1 (AA) (Aa) (aa) Microevolution Involves small or minor changes in the allele frequencies within a population Five processes have been identified: Nonrandom mating (inbreeding & assortative mating) Gene flow (migration between populations) Genetic drift (bottleneck effect) Mutations (unpredictable change in DNA) Natural selection (differential reproduction) **certain alleles are favored over others in nature Microevolution A change in the gene pool of a population over a succession of generations Genetic drift: changes in the gene pool of a small population due to chance (usually reduces genetic variability) Molecular Clock-Pg 385 Used to estimate the time of divergence between two closely related groups when their common ancestor could have been present. Mutations tend to occur at a steady uniform rate over millions of years for closely related species. These alterations in the DNA sequence used with geological data Allows scientists to reconstruct the evolutionary history of a group and describe its phylogeny A single molecular clock for all genes and all species cannot be established. (Why?)