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What are the Foundation Theories of Biology?
Cell Theory and Theory of Evolution mid-1800's
Who Was Robert Hooke's?
first view of cells, made drawing from 1665 OAK BARK
Who Was Anton van Leuwenhoek?
First to view single-celled "animalcules' in pond water
What is a Cell?
compartments outside plasma membrane with a mixture of chemicals in a accua solution, capable of duplicating reproduce by dividing. Chemicals used to metabolize and promote energy
What is Biology?
The study of life, Characteristics, classification, behavior of organisms. Biology also explains Birth, Decay, and Death.
What is Cell Theory?
Cells basic structral units of organisms functions made of cells from pre existing cells. Links all organisms together with a common ancestor.
What are the problems with cell theory?
Where did the first cell come from.
Clay, Electricity, molecules. Cell first came into being Billion years ago
Are viruses alive?
What did Luis, Pasteur Experiement in the Spontaneous Generation Hypothesis?
Broth put in flask, steralize it to see if cells are in it. Bottom line Cells only come from pre existing cells! Cells do not arise spontaneously.
Who came up with the Theory of Evolution by Natural Selection?
Charles Darwin & Alfred Wallace
What are the Biology Foundations for Evolution?
Common Ancestory, Species change through time,
What are the Biology foundations for Evolution Through Natural Selection?
Fitness, and Adaptation
2 Conditions for Natural Selection?
Population or group of organisms in a defined area have to be heritable or passed to generations, group of same speicies interbreeding.
Two Central, Unifying ideas of Biology?
Cell= fundamental structural unit of all organisms. All species related by comon ancestry and have changed over time via natural selection
What is Tree of Life?
Speciation, Linnean Taxonomy=namethings, Carolus linnaeus (Karl von Linne'), Taxon (Taxa)=More than one
What is Tree of life: Taxonomy?
Scientific or Latin Name: Genus(singular), General(Plural), Homo, Species (e.g. Sapiens)
What are the Tree of Life's Taxonomic Levels?
Kingdom, Phylum, Class, Order, Family, Genus, Species
What are the Two Linnean Kingdoms?
Animalia and Plantae
Whatare the Linnean Kingdoms problems?
Molds, Mushrooms, other Fungi and Bacteria. Can move but some move and get food from other places or make own food
What is Phylogeny?
Classify beyond apearance- consider genealogical relationships= true historical relationships among types of organisms.
Multi Celled and have Nucleous
No membrane bound Nucleous, Bacteria and single Celled
What does Kingdom Monera include?
All prokaryotes
What does KingdomProtista include?
Several groups of unicellular eukaryotes
Who created Phylogenetic Tree of life?
Carl Woese et al. Classify by molecular components of cells. The Tree of Life was created based on Rrna
Tree of life is configured by?
3 Domains then which fall under all the different Kingdoms
How does Biology Get Done?
Hypotheses, Experimentation/Observation and Testing
Why do Giraffes have long necks?
Food Competition Hypothesis: Predictions and Test
1. Neck length is variable among giraffes,
2. Neck length is a heritable trait.
3. Giraffes feed high in trees, especially when food is scarce.
What was the outcome of Sexual Competition Hypothesis with Giraffes?
1. Longer neck result in more forceful impact.
2. Males with longer necks compete better, win more often, and father more offspring
Outcomes to Giraffes?
1. Substantial amounts of feeding occur at low levels, even when food is scarce
2.Long-neck males were more successful in fights and mated more often
3.Male head/neck is proportionally larger than the females.
What are the Key Points to Experimental Design?
Control must be induced
*Experimental conditioning must be carefully controlled
*Randomization must be used to minimize misalaneous effects among controlled groups
*Experiment must be repeated in large sample to produce more accurate results.
Why are Chili Peppers Hot?
The Directed Dispersal Hypothesis
A.Chilies produce fruits that contain seeds.
B.Cactus mice are seed eaters
C.Curve-billed thrashers eat chili fruits.
Does the presence of capsacin in chilles deter some predators but not others?
Dispersal hypothesis-Capsaicin deters cactus mice (seed predators) but not birds (seed dispersers.
Null hypothesis-Cactus mice and birds respond to capsaicin in the same way.
Predictions-Both will eat hackberry, but only thrashers will eat pungent chilies.
Prediction of null hypothesis-no difference between thrashers and mice in fruit consumed.
conclusion-The presence of capsacin deters cactus mice but not thrashers.
What is the Molecular Basis for Inheritance?
*DNA as Hereditary Material
*Testing Early Hypotheses about DNA Replication
*A Comprehensive Model for DNA Synthesis
*Replicating the Ends of Linear Chromosomes
*Repairing Mistakes in DNA Synthesis
*Repairing Damaged DNA
Does R Strain cause illness?
NO (benign)
Does S strain cause illness/death?
Yes (Virulent)
What strain is Heat killed?
S-Strain and its BENIGN
What happens when live R-strain is combined to heat killed-S strai?
Live-R-strain cells combined with heat killed S-strain cells are virulent
What was the Conclusion of R&S strains
Benign R-strain cells were transformed into virulent S-strain cells
What were the Implications of Griffith's Experiment?
*Chromosomal theory of inheritance
*Genes make up chromosomes
*Chromosomes=complexes of DNA & Protein
*Chromosomes theory confirmed
*Gariffifth's transforming factors had to consist of DNAor protein
Genes (unit that determines specific trait blond hair) are made of dominated biology during the middle of the 20th century.
*Once DNA was identified as the hereditary material, research could show how genes were copied and if there was a mistake during gene replication
What was DNA as the Hereditary Material?
*Avery,McLeod and McCarty
*Is Protein,DNA,or RNA responsible for the transformation of S. Pneumoniae observed by Griffith?
*Proteins with great complexity and potential
*DNA known to be composed of only 4 types of deoxyribonucleotides, so thought to be too simple of a molecule.
How do strains of streptococcus pneumoniae intereact?
*Leading cause of multiple infection types.
*Gariffifth worked with strain that fix mice.
*Strain=population of genetically identical individuals.
*Virulence-ability of strain to cause illness/or death.
*Virulent=disease causing benign=non-disease causing
What is Rough Colony (R)?
R-Strain is benign (lacking a protective coat, it is recognized and destroyed by the host's immune system).
What is Smooth Colony (S)?
S-Strain is virulent (polysaccaride coat prevents detection by host's immune system).
What was the Conclusion of DNA as the Hereditary Material?
*Only extracts with intact DNA could transform cells to virulence.
*Hypothesis that DNA is hereditary material is supported.
What was the Hershey-Chase Experiment?
*Alfred Hershey&Marsha Chase
*T2 virus & Escherichai ecoli
1.Start of infection. Virus gene enter host cell. Protein coat does not.
2.Virus genes direct the production of new virus particels.
3.End of infection. New generation of virus particles bursts from host cell.
What did Hershy-Chase know about the Experiment?
*Virus attaches& injects genes.
*Cell=host for virus.
*Genes direct production of new genes of virus particles.
*Protein coat left behind as a "ghost"
*T2 coprised of nearly all protein & DNA.
So in Hershy-Chase, What goes into the host cell?
Virus genes
what was the conclusion in the Hershy-Chase case?
Viral genes consist of DNA. Viral coasts consist of protein.
what was the overall out come of the Hershey-Chase Experiment?
*by radioactively labeling the virus's DNA with 32P and its protein with 35S, they demonstrated that DNA is the genetic material.
Who was involved in DNA Structure (Deoxyribonucleic Acid)?
*Watson&Creek (1953)
*Polymer of monomers(nucleotides)
*Double Helix
*Complementary base pairing
What is DNA Replication?
Genetic information must be accurately transferred from one cell to another during growth and from parents to offspring during reproduction.
*In all 3, The existing DNA molecule serves as a template, or guide, for synthesizing the new molecule.
What are the Three Mechanisms of DNA Replication?
Semiconservative Replication, Conservative replicatioin, and Dispersive replication.
What is Semiconservative replication?
Each old DNA strand is copied to generate a new strand.

Each new chromosome is composed of one strand of old DNA and on strand of newly synthesized DNA.
What is Conservative replication?
The original chromosome is copied but remains unchanged.
*One chromosome is composed of old strands and the other of new strands.
What is Dispersive Replication?
The replication process generates 2 new chromosomes
*New and old sections of DNA mixed together randomly.
What was the Meselson-Stahl Experiment in (1958)
*DNA tagging
*E. coli
*Nitrogen (N) isotopes=different densities
What was the outcome of Meselson-Stahl Experiment (1958)?
*Grew E. coli in the presence of "heavy" nitrogen (15N) to label the bacteria's DNA.
*After many generations, they moved the bacteria to normal 14N containing medium and separated the DNA by density.
What was the DNA Replication Results in Meselson & Stahl's Experiment?
Results supported semiconservative DNA replication as the mechanism by which the hereditary materal is duplicated
What was the DNA Replication Enzyme?
*Kornberg et al. mid-1950s
*Hypothesis: DNA replicating system requires an enzyme to catalyze the formation of phosphodiester bonds between nucleotides in the newly formed strands.
What is Asexual Reproduction?
*Any mechanism of producting offspring not involving fusion of gametes
*In eukaryotes, mostly by way of MITOSIS
What is Mitosis?
Advantage reporduce quickly, unicellular reproduce lots of offspring in a short period of time.
*Daughter cells identical to parent cell.
*Chromosomes identical.
*Because chromosomes are made up of genes.
*The offspring are clones.
*(genetically identical)to parent.
Whats the Cell Division- Mitosis?
2 of each type of chromosome.
*Diploid parent cell.
*Chromosome replication.
*Meaphase-individual chromosomes align at the metaphase plate.
*Two diploid daughter cells of mitosis.
*Anaphase and Telophase-sister chromatides separate.
What is Sexual Reproduction?.
Sperm(male reproduce cell)Gametes.
*Egg(female reproduce cell).
*Fertilization produces zygote(fertile egg/new individual).
What are the Chromosomes basics?
Multi-cellular organisms-Have a constant number of chromosomes in all cells

*Chromosomes of parent/daughter cells-Number after cell division(Mitosis)
How many pairs of Chromosomes?
46 total and 23 pairs of homologoes pairs
What are the types of Chromosomes?
Homologs-Chromosome pairs.
*Sex chromosomes-XX Male, Y female.
*Autosomes-Non-sex Chromosomes.
What are the Chromosomes genes?
Homologs-Carry the same genes
*Gene-DNA sequence that influence one + hereditary traits
*Alleles-Different versions of a gene; alleles on homologs may differ.
*Gene Locus(loci)-Points on chromosomes where genes are located.
What are Chromosomes Karyotype?
*Karyotype-number and type of chromosomes present in an organisms cell.
*Homo Sapiens-46 Total and 23 distinct types.
*Ploidy-number of each type of chromosome.
*Diploid(2n)-Organisms with two of each chromosome.
*Haploid(n)-organism with one of each chromosome no homologs.
*Polyploid-organisms with greater than 2n(ex,triploid,tetraploid,hexaploid.
How can chromosomes from sperm & egg combine, but has the same chromosome number as each parent?
Must be something out there to allow this to happen Meiosis. Distinctive types of cell division must exist that lead*
What is Cell Division Meiosis?
*lessening act, Halving of chromosomes numbers, and precedes gamete formation.
What happens in Meiosis I?
Interphase:chromosomes extremely long structures, chromosomes replicated resulting in two sister chromatides.
What happens in Meiosis I?
Early Prophase 1
*Chromosomes condense
*Spindle apparatus
*Synapsis-homologs come together
*Tetrad-2homologgs;each homolog with two sister chromatids
*Non-sister chromatides-Chromotides from homologs non sister chromatides Red of to Blue chromotomes.
*paternal-blue from father
*maternal-Red from mother
*Network of proteins that hold homologs close, this is when things get swaped.
What happens in Meiosis I?
Metaphase I
*Centromere-microtuble organizing center.
*Tetrads moved to metaphase plate-*Microtubles comprise spindle apparatus.
*Tetrades move independantly
*Alignement of paternal & maternal homologs random.
What happens in Meiosis I
Anaphase I
Telophase I
cytokinesis I
*Anaphase I-homologs seperate and begin moving to opposite ends of the cell.
*Telophase I-homologs finish moving to opposite ends of the cell, Nuclear envelope reforms around each set of chromosomes.
*Cytokinesis-Cytoplasm divides, Two haploid (n) daughter cells formed, and sister chromatides still attached.
What happens in Meiosis II?
Prophase II
Prophase II-Spindle apparatus forms in daughter cells.
*Spindle fibers (microtubules) attach to each side of replicated chromosomes.
What happens in Meiosis II?
Anaphase II
Anaphase II- Sister chromatids seperate resulting un replicated chromosomes begin moving to opposite sides of the cell.
(2 cells)
What happens in Meiosis II?
Telophase II and Cytokinesis
Telophase II- Chromosomes finish moving to opposite ends of the cell.
*Cytokinesis-Cells divide, 4 total daughter cells result from each parent cell.
All daughter cells are haploid.
What are the Important outcomes of Meiosis?
*Chromosomes reduction prior to gamete formation.
*Chromosomesal makeup of gametes different from chromosome in parental cells due to Independent shuffling of maternal and paternal chromosomes.
*crossing over
*Also allows fertilization to give 2n offspring, haploid gametes from mother and father, chromosomal make up of offspring is thus unlike either parent. allows fertalization to take place resule in two offspring.
*Mom and Dad same amount of offspring unlike eihter parent.
What is Genetic Recombination?
Any change in the combination of alleles on a given chromosome.
*In species that reproduce sexually it occurs by crossing over during Meiosis.
*Increases genetic vairability in gametes. Offspring, vise versa paternal/maternal contain material.
What is Fertilization?
Self-fertilization-gametes from same individual combine to form diploid offspring.
*Out crossing-Gametes from different individual combine to form diploid offspring.
Why Sex?
Asexual reproduction-numerical advantage and superior "if all other factors equal"
*Changing environment hypothesis-Environment changes from 1 generation to the next.
*offspring genetically different from parents more likely to survive and reproduce.
*clones less likely to thrive with changing environment. This hypothesis has been suported through experiments.
Sex When?
Life cycle-Sequence of events occuring during life span of individual(fertilization to reproduction btw m/f).
*Meiosis,Haploid gametes,Fertalization,Mitosis allows fertile egg to create more cells. However, timing varies amoung species.
*Most animals are diploid dominant.
*Meiosis in reprodutive organs of adults.
*Gametes are the only haploid stage of the life cycle.
Sex when? Continued
Some eukaryotes are haploid dominant.
*Some algae
Diploid stage-diploid stage single celled structure thath is heat and drying resistent.
*Single cell-under goes meiosis.
*Resulting haploid cells-Divide by mitosis to generate haploid multicellular organism.
*Alterationof generations, Land plant and some algae.
*Angiosperms & firns-Haploid stage small and relatively short lived.
*Mosses-Haploid stage larger and longer lived than diploid plant.
Mistakes in Meiosis?
Aneuploid=cells with abnormal set of chromosomes.
*Occurs during Meiosis I (more rarely during Meiosis II.
*Trisomy-2n+1 Extra copy of chromosomes+downsyndrom
Klinefelter syndrome (karyotype)=XXY
*Trisomy X(karyotype)=XXX
Turner syndrome(karyotype)=XO
What happens if the mistake happens in Meiosis?

Take away
If mistakes occur during meiosis, the resulting egg and sperm cells may contain the wrong number of chromosomes. It is rare for offspring with an incorrect number of chromosomes to develop normally.
What is Heredity?
Inheritance-Transmission of traits from parent, offspring.
*Trait-Characteristices of an individual e.x.Height, eye color, hair color.
Gregor Mendel 1865?
Hypothesis 1
H1 blending inheritance male/female traits blend together to form offspring trats.
E.X. Black sheep+White Sheep=Grey sheep.
Garegor Mendel 1865?
Hypothesis 2
H2 Inheritance of aquired characters.
*Parent, traits moderate, through use and passed to offspring in moderate form.
E.X. parent giraffes acquire longer necks by straining to reach higher leaves, does it on to offspring.
What was Mendel's Experiment?
*Model Organism-Small,short lived, inexpensive to care for, prolific, and easy to manipulate.
*Pea,Pisum sativum, allowed Mendel to Observe-Many Generations. Large number of individuals very important.
*1st Model Organism for Genetics.
What was Mendel's Experiment continued?
Garden pea characteristics-usually self-fertilizing (selfing), pollen grains contain sperm and fertalized eggs.
*Mendel circumvented selfing-Artificial X-pollonation or cross(X) cross pollinated, allowed mendal to control matings.
Mendel's Experiment continued?
Pure Line-Individual that produced young identified to themselves when selfed or X'ed with another individual of that line.
*Hybrid-Mix of two types
*Mendal X'ed pure line to get hybrid offspring.
e.x. round seed individual X wrinkled seed individual.
What was Single Trait Inheritance Result?
F1 Generation-allowed seeds round, Blend, inheritance,Hypotheses not supported, wrink trait dissapeared.
*Disappearance of trait=Was wrinkled, trait determinant in egg vs. sperm.
Orgin of gamete have any part to play in result.
What was single trait inheritance result?
Not Supported by Mendal. Blending hypothesis-Parental traits blended in offspring.
*Inheritance of acquired traits-Traits that become modified in the lifespan of the parents passed on to the offspring.
What was the Sex matters Hypothesis?
Reciprocal cross- Set of matings where males phenotype in 1st=females phenotypein in 2nd cross. and females phenotype in 1st cross=males phenotype in 2nd cross.
*Conclusion=Seed shape not does not depend on gamete orgin.
Dominant and Recessive Traits
F1 Seeds Planted-Selfed when mature.
*F2 generation=5,474 round seed and 1,850 wrink(3:1)ratio.
*Wrink Traits "reappeared"after missing in F2
Dominant trait-Trait expressed when both alleles present(round seeds)
Recessive-Trait not expressed if both alleles present(wrinkled seeds)
New Hypothesis
Mendel ran experiments on other traits with same results.
*proposed particulate inheritance hypothesis-Heredity, determents,maintain integrity, through generation
*only explanation for phenotypes, dissapearing in 1 genearation and reappearing in next generation.
Modern Genetics
*Heredity Determinents-genes
*Different versions of same gene-alleles
*Alleles found in a given individual-genotype influence an individuals phenotype.
The integrity maintained through generations.
Principle of Segregation (PoS)
PoS-this is what Meiosis is all about.
*Alleles of each gene must segregate.
*gametes contain 1 allele of each gene.
Naming system-Letter represents gene, e.x. R=gene for seed shape, uppercase=dominant allele (R=round)
Lower case-recessive allele(r=wrink)
Heterozygous-Individual with different alleles of same gene. e.x.Rr, Individuals with 2 copiesof same allele (E.x.RR or rr, pure lines homozygous.
Crosses (Punnett Square)
When you cross r r with R R you get Rr,Rr,Rr,Rr. Offspring genotype all Rr (heterozygoes)
Offspring Phenotypes=all round seeds.
Crosses (Monohybrid Cross)
When you cross R r R r you get RR, Rr, Rr rr. Offspring genotypes 1/4 RR and 1/2 Rr and 1/4 rr. Offspring phenotype 3/4 round 1/4 wrinkled.
Principle of Independent Assortment (PoIA)
PoIA-started as hypothesis to be tested.
*Allels seperate and sort independency of each other before gamete production.
*E.X. seed shape and see color.
Alterative Hypothesis dependent assort=genes transformed to gametes together.
Dihybrid Cross-Crossing of 2 parent both heterzogoes for two traits.
PoIA Test Dihybrid Cross
Dhybrid cross confirmed principle of Independent assortment.
Mendel's Testcross
Mendel Invented
*Completely recessive parent crossed to determin unknown genotype of 2nd parent.
*Predict:1:1:1:1: ratio of phenotypes when crossed with heterozygote parent.
Cromosome Theory of Inheritance
Mendel's rules of inheritance explained by *Independent alignment of homologs.
*Seperation of homologs(MeosisI)
*Both occur during Meiosis I.
Mendel's Contributions
ModelOrganism-Pea was good choice.
*Use of Pure Lines-Lines with different discrete traits.
*Easy to track transfer of traits to offspring.
*Large Numbers,*Rules of Probablility,*Reciprocal Crosses-allowed test of sex's role in transmitting traits. *Testcross-Determined parent genotype.
Meiosis I
Recombinant=individuals with combination of alleles different from parent generation (result from crossing over in Meiosis I)
*Linkage ultimately depends on how close genes location to each other.
Sex linked traits
Thomas Hunt Morgan
*Drosophila melanogaster-not domesticated, not readily available info on phenotypes.
*1st work to characterize individuals with different phenotypes-*Wild type=most common phenotype.
*Mutation=change in gene(white v.s. Red eyes.
*Mutant=Individual with traits attributal to mutation.
Sex Associated Hypothesis
Morgan crossed male + Female
*All progeny red-eyed-consistwith white eye as single recessive allele
Tested by crossing f1 female + F1 Male-F2=3:1 red eyed to white eyed. But all of the white eyed were males. Associated between eye color and sex.
Sex Associated Hypothesis
Sex Chromosomes-X and Y
*Synapse together in Meiosis I.
*Differ in size,shape and gene content
X-Linked Inheritance or X-Linkage-E.X-X chromosomes carries white eye allele.
Sex linked inheritance or sex-linkage
Sex Matters Hypothesis
Tried to show how trait was being produced through Genetics, Recipical Cross
Red eyed M/F
Sex Matters
Extending Mendel's Rules
*Mendel's pea phenotypes affected by only alleles at single gene-many traits in peas and other organisms influence by multiple genes.
*Only two alleles in Mendel's pea line-most populations of species with dozens or 100s of different alleles at each gene
*Alleles studied were either complete dominant or complete recessive-often there is incomplete dominance or co-dominance.
Extending Mendel's Rules
Mendel worked with discrete traits-Changes that are qualitatively different, more common traits show quantitative vairation, polygentic inheritance(most genes determin phenotype)E.X. human height.
*Non Sex chromosomes in Mendel's peas-so no sex linked characters.
*Linkage not a factor
Heterozygotes with phenotypes associated with both alleles present.
*MN gene in humans
*Codes for proteins in red blood cell membranes.
*Both phenotypes expressed when both alleles present
E.X. Cows=red cow mix white cow. Both red and white hairs present, both phenotypes codomant
Multiple Allelism
E.X. ABO blood type in humans
Some genes located on same chromosomes
only on sex chromosomes
*genes cant independent assort if on the same chromosomes
*but genes occur at specific sites on chromosomes.
Incomplete Dominance
RR produces a lot of pigment=purple flower
rr produces no pigment=white flower
Rr produces some pigment=lavender flower
Genes: Environmental Influence
Phenotypes can be influenced by the physical Environment.
*Gene-environment interaction
*Neither genes nor environment solely responsible for phenotype in almost all cases.
Gene Interactions
*Alleles of different Genes can Affect Each other-Interaction influences the observedphenotype.
*Epitasis-one gene affects the action of another gene
*Making or diminishing.
E.X. fruit colors in bell peppers.
Process Epistasis influencing genes.
Polygenic Inheritance
Quantitative traits-*population with normal distrubution.
*Intermediate phenotypes exist
E.X. height,weight,skin color
*Individual different by degree
Many genes influence a single trait-E.X. gene adds a small amount of value to the phenotype.
E.X. wheat kernel color
Theory of Evolution by Natural Selection (TENS)
Common ancestry-species existing today descended from other pre-existing species
Change-Species chang through time
Theory of Evolution by Natural Selection's History
Charles Darwin (1842)Wrote 1st paper on TENS
Never submited for publication, private person and poor health
Alfred Russel Wallace (1858)wrote beliefpaper on TENS. Sent paper to Darwin, and Nearly scooped Darwin.
Both papers read together at Linnean society of London.
Darwin rushed Publication of the Orgin of Species.
1st Eddition sold out first day.
Who was Thomas Huxley
defended theory of Natural Selection against theory of Darwin.
Contrasting Theories
Theory of Special Creation (Creationisms)
Independent-God created all species independently
Immutable-Species are incapable of change
*Not experimentally testable, Faith based.
TENS-Experimentally testable science based.
The Pattern of Evolution
Descen with Modification (Darwin)
Todays species descended from other pre-existing species
*Species change through Time
Decent with Modification
Evidence for change through time
*Fossile-any trace of past organisms, impressions,bones,teeth,shells,dung,tracks
*Fossil Record-All fossils found and described
*Sedimentary Rocks-Formed from sand and mud.
*Form in Layers-older layers lower.
Most fossils found in sedimentary rocks
Ex.old beaches and river mouths
Change Through Time
Fossil Organization
1st Based on Location in Sedimentary Layers, Relative age-fossils in lower layers considered older. Older to younger sequences.
Geologic time-Eons, Epochs, and Periods
Radiometric aging
*Absolute age vs. relative age
*Earth-about 4.6 billion years old.
1st life-about 3.85 billion years ago
Change Through Time
Extant Species-Species still in existence alive today
Extinct Species-Species that no longer exist
*Extinction throughout Earths history.
*Many fossils unlike any know extant species. Throughout History part of life.
Fossil Record some species dont fit anything alive today
Change Throught time
Transitional Forms
Before Darwin:
Pattern Observed-Resemblance between fossile and extant species. Within the same geographic areas
Law of Sucession-Extinct fossile succeeded by similar species.
Change through Time
Transitional Forms
Interpreted Resemblance between Extinct and Extant-Extinct and Extant related.
Ancestory and decendents.
Strong evidence for species change through time hypothesis
*Transitional Forms-Fossil species that are intermediate between older and younger species.
Changes Through Time
Environmental Change
Theory of Plate Tectonies-Earth's crust made up of moving plates.
Tectonic Uplift-e.g. himalayas, colorado plateau,
Beach and mud deposits now
1,000's of meters above sea level.
Environment has chaned dramatically over time-organisms have changed too.
Change through Time Summary
*LIfe is ancient
*Species have changed through time
*Planet and species are dynamic not static
*Supported by-Vetigial traits
*Reduced/incompletely developed structures.
*no function or reduced functions.
*Similar to functioning structures/organs in other organisms.
Species Relatedness
3 Levels of Resemblance
2nd=Developmental Homologies
Vertebrate=Developing vertebrate embryos of different species with similar traits.
2nd levels 1st animals with back bones.
Over all morphology of embryo
Species Relatedness:
Genetic Code
Set of rules by which information encoded in genetic material (DNA or RNA sequences)by living cells.
Codon-Tri-nucleotide sequence specifying an amino acid
64 MRNA codons
Homologous vs Analogous Traits
Evidence for Evolution:
*Species are not state and change through time.
*Many species have gone extinct
*Fossil species frequently resemble living species in the same area.
*Transitional forms document change in through time.
*Vestigial traits common
*Populations of species can be ovserved changing now.
*Species are related, not independent.
*Closely related species occur in same geographic region.
*Homologous traits common and exist at 3 levels, Structural, developmental, and genetic.
Species Relatedness: Evidence
Genetic Code-Set of rules by which information encoded in genetic material (DNA or RNA sequences) translated into proteins (amino acid sequcences) by liveing cells
*Codon=Tri-nucleotide sequence specifying an amino acid.
*64 mRNA codons-same 764 codons specify the same 20 amino acids in all organisms that have been studied (with few exceptions).

Sme code in common ancestor and passed on to extant species Today.
Powerful code based on small number of Amino acids and codons, come from common ancestors passed on to every thing else to develop protein needed.
Genetic Homologies
In terms of content not much different to each other, Homology at genetic but not structural level
*compound vs. camera eyes.
*Conclusion=both had ancestors with gene for light gathering organ.
Homologous vs. Analogous Traits
Similarities that exist due to common descent
Analogous Traits (also Convergent Traits)
Similar traits that are not inherited from a common ancestor.
Convergent Evolution
Natural selection favors similar solutions to the problems passed by a shared life strategy
*E.X. Ichthyosaurs & Dolphins-Characters help chase down prey fish regardless of ancestory.
Homologous Traits: Genetic Basis
*HOM(insect)& Hox(verebrate)Genes-Derived from same ancestral sequences
*Products of these genes with similiar functions.
*Such similarity unlikely from convergent evolution, Passed down from common ancestor.
Evidence for Evolution: Summary
*Species are not static and change through time
*Many species have gone extinct.
*Fossil species resemble living species in the same area
*Transitional forms document change through time.
*Vestigial traits common
*Populations of species can be observed changing now.
Species are related, not independent
*Closely related species occur in same geographic region
*Homologous traits common & exist at 3 different levels.
Structural,Developmental, and genetic.
Evolutionary Process
Natural Selection
*Variable Traits-Individual organisms in a population vary in traits they possess.
*Heritable Traits-Some of the different traits passed onto offspring;trait with genetic basis and heritable
*Reproductive Success Varies-only a subset of offspring survives long enough to reproduce of these not all produce the same number of offspring.
*Certain Traits More Advantageous-Individual with certain traits more likely to produce greater number of offspring in a given enviroment
*Change in allele frequency in a population
*The TB population changed over time because the mutant gene increased in frequency
*but the individual cells did not evolv and they simply lived or died, or produced more or fewer offspring,
*Natural Selection acts on indidviduals, but only populations evolve.
Tests of Evolution
Mycobacterium tuberclulosis-
*Resistance to antibiotics
*Largely controlled
*1980s TB infection rates increased in many countries
*Strains largely resistent to conventional treatments
Stared with HIV-Infected individuals-
*Aggresive antibiotic treatment worked for a while
*Lungs cleared of TB
*But, individual eventually died from TB
*TB in lungs highly resistant to antibiotics
Test of Evolution
Did Variation Exist in the Population
*Mutation occured-So, YES there were normal and mutant
Was the Variation Heritable-Phenotypes-drug resistance vs. drug susceptibility
*These phenotypes due to variation in genotypes
*Yes, the allele and resulting phenotype were passed on to the offspring
Was there Variation in Reproductive Success-Yes resistant types more sucessful
Did Selection Occur-Did a non random subject of the population produce the most offspring,YES
Galapagos Finches
Medium Ground Finch(MGF)
Daphne Major-Small,island with population of MGF
*All individuals on island caught, weighed, measured.
Beak sizes and shape, and body size vary and are heritable.
Evolution Galapagos Finches
1977: Drought on Island-Poor seed production by plants on island.
*Seed availability changed; mostly tough fruits remained
*84% of the MGF dissapeared through starbation.
Dramatic Selection Event for MGF-Differences between suvivors and non survivors.
*suvivors with much deeper beaks than dead ones
Evolution-Galapagos Finches
1983:Particularly Wet Year
*Plant Growth-Luxuriant on island
*Seed availability-mostly small, amount of seed present
*Individuals with small, pointed beaks were especially sucessful reproductively.
*Population characterisitcs-Changed again
Evolution-Galapagos Finches
Point, Population of organisms evolving with changes of environment over time.
Experiment:group of sky pilots, bees polinate sample, control group. Polinate by hand.
Evolution Experimentatioin
Bees go to taller and larger one.
*Bee's select and promote taller flowers.
*population evolve overtime to begger flowers.
Natural Selection
Individuals and Populations
*Natural Selection-Acts on individuals, but individuals does not fisically change
E.X. finch beak depths didn't just get deeper
Evolutionary Change-Occurs in Populations
E.X. average beak depth increased over time because deeper beaks individuals produced more offspring than shallow beek individual.
Natural Selection vs. Inheritance of Aquired Characters
Inheritance of Acquired Characters-Individuals change in response to environment and pass change on.
Natural Selection-Individuals do not change when selected-They simply produce more surviving offspring
Individuals vs. Population Change
Acclimatization-Changes in individuals
*Individuals change in respone to enviromental change
Adaptation-Populations change in respone to natural selection
Individual Vs. Population Changes
E.X. Wood Frogs-over winter in frigid climate
*Ability to produce natural antifreeze to protect tissues from freezing (adaptation ability)
*Production of antifreeze molecules when ice begins to form (Acclimatization)
Evolution NOT Progressive
Does ENS make Organisms Better?NO
Morphological complexity-organisms later in fossile record often more "advanced" E.X. flowering plants vs. mosses
But, complex traits routined lost or simplified over tim do to Evolution by natural selection
E.X. Tapeworms with no gut, but evolved from species with sophisticated digestive tract.

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