Absent students/make-up Absent students/make-up Chapter 22- go over quickly Chapter 22- go over quickly Lab results/complete and turn in Lab results/complete.

AP Biology

AP BiologyAbsent students/make-upChapter 22- go over quicklyLab results/complete and turn inEvolution- change over time OR descent with modification

Proposal that Earths species are descendants of ancestral species that were very different from those alive today.

Pattern- data driven based on observations of the natural world. Process- mechanisms produce diversity of living things. Evolution Aristotle- 384-322 A.D.- opposed evolution, scale of nature everything is fixed, from simplicity to complexity.

Linnaeus (1707-1778) developed naming system. Grouped based on similar characteristics into general categories, from the pattern of their creation.

Cuvier (1769-1832) paleontology, thought catastrophism- boundaries due to catastrophes that destroyed a speciesHow Did We Come to Evolution?Hutton (1726-1797) Proposed gradualism- said that geologic changes took place through the cumulative effect of slow continuous change

Lyell (1797-1875) - Uniformatarianism which stated that things dont change over time

Lamarck (1744-1829) Believed in several lines of descent called it inheritance of acquired characteristics.Darwin (1840s) proposed the idea of natural selection in which individuals with certain inherited characteristics leave more offspring than individuals with other characteristics. He called these ADAPTATIONS characteristics of organisms that enhance their survival and reproduction in a specific environment.

Darwin never coined the term evolution rather: descent with modification Organisms are related through descent from a common ancestor that lived in the past that explains the unity of life.

These descendants have accumulated diverse modifications, or adaptations, that allow them to survive and reproduce,

Over long periods of time this descent with modification has led to the rich diversity we have today.3 Major Contributions from DarwinDarwins proposed mechanismsArtificial selection

Humans have modified a variety of domesticated plants and animals over many generations by selecting individuals with the desired traits as breeding stockNatural selection

Organisms have heritable traits that enable them to reproduce at a higher rate Overtime these traits increase a match between organism and environment.If the environment changes or if individuals move to a new environment, a new species could result in the process.Individuals do not evolve populations do.

Natural selection can act only on heritable traits.

Environmental factors vary from place to place and from time to time. Important points4 major types of data:

Direct observationFossil recordHomologyBiogeography Sounds Great- Wheres the Data?Page 461 Case Study

Page 462 Case Study 1. Direct Observation2. Homology

Homologous structures same structure different function

Vestigial structures remnants of features that served a function in the organisms ancestors

Molecular similarities

Embryology HomologyEvolutionary tree- diagram that reflection evolutional relationships among groups of organisms Tree

Convergent evolution independent evolution of similar features in different lineages.

Analogous- different structure, same function as a result of convergent evolutionDifferent Cause of ResemblanceFossil record is NOT completeCan be used as indirect or direct evidence in some situations.3. Fossil recordThis relates to the geographic distribution of species. Influenced by many factorsContinental driftEndemic- species on island are found nowhere else in world.

4. BiogeographyAP Biology Quiz today!!! Describe the difference between direct and indirect evidence supporting evolution.

Explain the difference between homologous and analogous structures.

Explain natural selection and how natural selection was developed.

QuizIs the finch evolving?

Individuals DO NOT evolve populations do

Natural selection acts on individuals meaning traits affect its survival and reproductive success

The effects of natural selection are only apparent in changes within a population over timeSmallest unit of EvolutionMicroevolution change in allele frequencies in a population over time

What affects change in allele frequency?1. Natural selection 2. Genetic drift events that alter frequency3. Gene flow transfer of alleles between populations Differences among individuals in the composition of their genes or other DNA segments.

Not all phenotypic variation is heritable onlyGenetic variation

Discrete characters determined by a single locus

Quantitative characters- vary along a continum Darwin and MendelVariation occurs between populationsGeographic variations- differences in genetic composition of geographically separate populations Genetic Variation contd.New genes and new alleles originate by mutation

Sexual reproduction results in genetic variation as existing alleles and genes are arranged in new ways

New alleles arise by mutationMutationSome organisms mutate faster than others

Compare: sexual reproduction to HIVHIV- no DNA, RNA mutates faster (that is why a single treatment is not effective)Sexual reproduction crossing over, independent assortment, fertilization Mutation ratesPopulation a group of individuals of the same species that live in the same area and interbreed to produce fertile offspring

Gene pool- the total alleles for the individuals in a population Hardy-Weinberg This principle states that the frequencies of alleles and genotypes in a population will remain constant from generation to generation if these conditions are met:

NO mutationRandom matingNo natural selection Extremely large population size (genetic drift)NO gene flow (immigration/emigration)

Hardy-Weinberg p + q = 1

p - the allelic frequency of Pq - the allelic frequency of p

Hardy-Weinberg( p + q )( p + q ) = 1 Orp2 + 2pq + q2 = 1

p2 frequency of PP 2pq frequency of Ppq2- frequency of ppHardy-WeinbergH-W500 wildflowers in the population 1000 total genesCR CR red (320)CW CW white (20)CR CW - pink (160)

Lets find the allelic frequenciesCR 1. Find the # of CR in the pink flowers ____2. Find the # of CR in the red flowers ___________3. CR frequency = ______________________

H-W500 wildflowers in the population 1000 total genesCR CR red (320)CW CW white (20)CR CW - pink (160)

Find CW frequency Find CW in the pink flowers _______Find CW in the white flowers ______Allele frequency ___________

H-W Nonradom mating- can affect the frequencies but usually have no effect on allele frequencies in the gene pool.

Natural selection Alleles are passed on to the next generation in frequencies different from their relative frequencies in the present population.Changes to H-W can alter allele frequencies in populationGenetic drift chance fluctuations in allele frequencies in small populations

Large populations allele frequencies do not change from generation to generation by chance alone.The smaller the population the greater chance of deviation

Small populations fall into 2 groups Founder effect - Bottleneck effectChanges to H-W can alter allele frequencies in populationFounders effect

When a smaller group establishes a new population whose gene pool differs from the source population Bottleneck effect

Sudden change in environment, a severe drop in population

Gene flow the transfer of alleles among populations due to the migration of fertile individuals or gametes Directional selection

Stabilizing selection

Disruptive selection - Three modes of SelectionIf you didnt turn in your quiz last class please do so now

H-W quiz later in class period

Chapter 24-25 today

Study guides/lab finishAP Biology Sexual dimorphism differences between sexes in secondary sexual characteristics (size, coloration, ornamentation)

Intrasexual selection direct competition among individuals of one sex for mates of the opposite sex (battles/patrol/rituals)

Intersexual selection mate choice, when memebers of 1 sex (usually female) select mates.Sexual selectionDetermined at genotype level

Heterozygote advantage maintains genetic diversity at the human gene

Sickle cell- SS normal rbcsSs Protected against malariass sickle cellHeterozygote AdvantageSpeciation process by which one species splits into two or more species.

Speciation concept EMPHASIZES reproductive isolation

Reproductive isolation biological barriers that prevent members of two species Chapter 24 Prezygotic barriers fertilization block

Postzygotic barriers fertilization occurs but may prevent hybrid zygote from developing into a viable, fertile adultReproductive isolationHabitat isolation different habitats even if in same geographic area

Behavioral isolation courtship behavior to attract mate

Temporal isolation breed at different times

Mechanical anatomically incompatible

Gametic gametes do not form a zygote PrezygoticReduced hybrid viability genetic incompatibility, may abort or produce frail offspring

Reduced hybrid fertility even if hybrid is vigorous, hybrid may be infertile

Hybrid breakdown first-generation is viable and fertile, but next generation is feeble or sterile Postzygotic Allopatric speciation geographic separation of population restricts gene flow

Geographic barriers (mountain ranges, glaciers, land bridges, canyons etc) Speciation Sympatric speciation speciation occurs between populations that live in the same geographic area.

Note** reproductive barriers must exist for this to occur.

Example: polyploidy, habitat differentiation, sexual selection, SpeciationPolyploidy results in extra sets of chromosomes

Autopolyploid individual that has more than two chromosome sets all derived from a single species

Allopolyploid when two different polyploids mateSpeciationGradulaism slow steady continuous change

Punctuated equilibrium rapid change followed by stasis

How long does this take?Quiz today last H-W quiz

Please turn in pGLO labs if you havent yetEmail me H-W modeling labAP Biology Macroevolution broad pattern of evolution above the species level

Chapter 25Abiotic synthesis of small organic molecules (monomers) Joining of monomers into macromoleculesPacking of these molecules into protocells, (droplets with membranes that maintained a distinct internal chemistry Origin or self-replicating molecules that eventually made inheritance possible What scientists thinkAbiotic synthesisOparian and HaldaneHypothesized the conditions on early Earth favored the synthesis of organic compounds from inorganic precursorsMiler and UreyTested the hypothesis, they recreated conditions on Earth, discharged sparks (lightning) and gasses and water vapor Results amino acids and other organic molecules formed.

How do we test these?Protocells self assemble Must have had reproduction capabilities and energy processing (metabolism)

These conditions likely produced vesicles (fluid filled compartments bound by a membrane-like structure)

Research has shown that given lipids and other organic molecules, vesicles will self-assemble ProtocellsRNA may have been the first genetic material

RNA catalyst called ribozymes can make short pieces of RNA when supplied with nucleotide building blocks RNA An incomplete chronicle of evolutionary change

Radiometric dating decay of isotopesRelative dating where fossils are in strata comparative dating

Fossil RecordHistory of Earth has been divided into 3 eonsArchaeanProterozoicPhanerozoic Eras: Paleozoic, Mesozoic, Cenozoic Eons

Evolution of photosynthesisMost atmospheric oxygen is of biological origin, from the water-splitting step of photosynthesis

Eukaryotic cells are more complex than prokaryotic cellsEndosymbiont theory suggests that mitochondria and plastids were small prokaryotes that began living within larger cellsMutually beneficial for each cellBecame increasingly interdependent Serial endosymbiosis supposes that mitochondria evolved before plastidsEndosymbiont theoryTheory suggesting that continents drift movement is continental drift (measured data)PangaeaMass extinction Habitat destroyed, environmental changesBiological factors may changeGlobal environmental change

Plate tectonics5 documented mass extinctions

Permian volcanic eruptions divided Paleozoic and Mesozoic eras. 96% species were extinct.

Cretaceous meteorites, boundary between Mesozoic and Cenozoic eras more than half species went extinct (dinosaurs included)

Mass extinctionsOccur when a few organisms make their way into new areas, or when extinction opens up ecological niches for surviving speciesAdaptive RadiationEvolution is not goal oriented

Hardy- Weinberg quizzes redo

Chapter 26 Phylogeny

TURN IN YOUR LABS if you havent done so

Study guides review Blast Lab - introAP Biology Phylogeny is the evolutionary history of a species or groups of species

Systematics system used to classifying diversity and determining the evolutionary relationships of living and extinct organisms

Taxonomy - determines how organisms are classified and named.

Chapter 26Linneaus developed a naming system : KingdomPhylumClass OrderFamily Genus Species

Clade- grouping of organisms which include ancestral species and all of its descendants

Shared derived character evolutionary novelty unique to a particular clade

Shared ancestral character originated in an ancestor of the clade

Example: Human s shared derived- hairshared ancestral vertebrae

Scientists identify each of the following:

Outgroup species or group of species that diverged before the lineage that includes the species being studied

Ingroup species being studied and their relatives Naming systems5 kingdom naming system:Monera (prokaryotes) Protista (mainly unicellular eukaryotes)PlantaeFungiAnimaliaProblems As data comparisons came in they found organisms that were grouped could be very different from each other SO

Scientists revised their system to a 3 domain systemOrganisms are grouped into 3 major domains of life: Archaea diverse group of prokaryotes inhabiting wide variety of environments Bacteria most prokaryotes including bacteria most closely related to chloroplasts and mitochondria Eukarya includes all organisms with a true nuclei (however plantae, Fungi, and Animalia are still recognized) Grouping of organisms

AP BIOBlast lab next class online already

Today finishing up rest of unit

Test March 6

See cabinet for sign ups for classes next year (Honors Anat. and Phys.)Prokaryotes vs Eukaryotes ProkaryotesMost Unicellular0.5-5 mFlagella Internal foldingsCircular DNABinary Fision Many shapesSpherical (cocci)Rod-shaped (bacilli)spiral(spirilla)

EukaryotesUnicellular and multicellular10-100 m

Cell wall of peptidoglycanGram-staining used to classify bacteria based on amount of peptidoglycan

Gram positive lots of peptidoglycan (purple)Gram negative less peptidoglycan (redish)

Bacteria vs Archaea

Lack complex structures, but have infoldings of plasma membrane, for metabolism

Lack true nucleus nucleoid

DNA plasmids

Divides via binary fission

Conjugation DNA is transferred between two prokaryotic cells Prokaryotes

Obligate aerobes must use oxygen for cellular respiration

Obligate anaerobes poisoned by oxygen, live via fermentation

Anaerobic respiration substances other than oxygen

Facultative anaerobes use oxygen if present but can also carry out fermentation or anaerobic respiration MetabolismPhylogeny

Extremophiles lovers of extreme conditionsHalophiles salt loversThermophiles heat loversMethanogens release methaneArchaea

Majority of prokaryotesVaried in structures and function

Page 568-569 for more detailsBacteriaSmall eukaryotes Some have flagellaSize ranges between 0.5 2 mHave a nucleusHave membrane bound organelles (mitochondria and golgi)Protists