Is a Giraffe Neck Long or Short?Hyp1- Foraging Behavior•( eating from higher leaves/ trees)Hyp2- Aggressive Behavior•( the male giraffes would fight one another very roughly and it was seen as a mating display)Giraffes are herbivores ○Main mechanism of escape is most likely running○Longer legs= greater speed○Long legs= difficult to get water ( critical)○Hyp3- Longer Legs•NO SINGLE SOLITARY HABITAT THAT CAN CHANGE AN ANIMAL TOTAL ACTIONS AND GENETIC MAKEUP•These hypothesis are somewhat obscure because the giraffes are being analyzed from only one standpoint and they do not explain why other animals don't have long necks to compensate for the competition with plants and resources•Biological Systems are not linear, it has a cycle/ rhythmBiological systems have a positive and negative feedbackEvolution as a hypothesisEvolution- organisms change through time•Species are not fixed•Historical Development of the HypothesisLinnaeus- classification scheme( binomial nomenclature)1.Hutton- proposes a system of gradualism geological formations have different layers created at different times2.Earth was considerably older than religious beliefs•Adam Smith- Laissez Faire economics ( hands off) let the system do as it shall3.Lamarck- system of acquired characteristics4.Malthus- population grows geometrically5.Resources decreases population will crash•Lyell- wrote the defining tome on the synthesis of geological thought ( how different layers were produced)6.Studied fossils and realized you see things within a time period•Cuvier- conveyor of studies in paleontology7.Darwin- Natural Selection as a mechanism of change 8.Wallace- co- founder of Natural Selection9.Published articles w/o sure verification•Mendel- origin of genetic relationships10.Evidence from Cell TheoryMicroscopic structure of organisms shows evidence of common ancestry1974-1916 Van LeeWanhook- discovered microorganisms1839 Scheidan- Plants made of cells 1839 Schelidan Animals are all made of cells1859-Vichrow All cells come from other cellsCells are the basic unit of life.Hypothesis for Natural SelectionIndividuals Vary○Variations are inherited○Populations tend to over breed ○Struggle for existence○Survival of the fittest○New Species Develop○Evolution occurs by process of natural selection given the assumptions•Why do imperfections exist in the fossil record?Most organism don't fossilize --> soft tissues and stable environment1.Fossils destroyed by erosion and geological disturbances2.Most fossils are inaccessible3.Fossils are hard to find4.Links are undefined phenomena imply distinct or unit connections.Transition SpeciesMore important concepts •May not be intermediate in structure or time•or relationship maybe a branch point where ancestors in transition range•Evidence from EmbryologyLaw of Development ( Von Baer)•General Traits appear first, before more complex traits•Specific traits appear later•Developments of all vertebrates are similar•Biogenic Law- Ontogeny recapitulates Phylogeny - Individual development repeats evolutionary history•Evidence from Comparative AnatomyFore limbs Bauplan -Basic anatomical plan( body plan)○Heart ○Gills and Lungs○Vertebrate Morphological studies •Evidence from Organ Systems - RespirationFish- gills•Amphibian- Gills, Simple Lungs•Reptile- Complex Lung ( 4 chambers 2 atria, 2 ventricles)•Birds have the best lungs○Birds and Mammals- Very complex lungs•Homology- Teeth, bones of the skull ( similar structure from common ancestors)Homoplasy- similar function but not derived from common ancestorVestigial Organs- structures w/ no apparent function or whose function differs from that of its ancestorsEx: Human appendix, human tail bone, wings in flightless birds, hind limbs bones of a whale•EukaryotesInternal membrane- Golgi apparatus. vacuoles, nuclear membraneMitochondria and chloroplasts9+2 flagella and ciliaMany chromosomesProkaryotesHave nucleusHave multiple chromosomesUse DNA as a genetic materialAre photosynthetic ( not all cells only plant cells)Evidence From GeneticsChromosomes found in nuclei 1)Numbers of chromosomes varies among species2)Chromosomes come in pairs( ALL EUKAROTIC ORGANISMS)3)Diploid=2n Haploid=n4)Polyploidy multiple copies5)Mendel's Factor's genes are located along chromosomes.6)Many genes exsist on each chromosome7)Genes are composed of DNA, RNA, Protein.8)Evolutionary Biology Final Review Fall 2011Monday, December 05, 201110:29 PM BIO Reveiw Part 1 Page 1Mutations IAbrupt changes in the species in the genetic material occurring typically during cell division in gametesChanges in the autosomal ( non sex cells) are irrelevant•Depletions a)Duplicationsb)A movement in the genetic form from one chromosome to anotherc)Loss or Duplication of whole genes1)Structural changes in Chromosomesi.Changes in gene arrangementii.Types of Mutations○Internally generates fragmentsTransposed elements are replicated and can be relocated to other regions of same/ different chromosomes. ^ increases variabilityTransposition○Down's syndrome- extra chromosome #21 ( trisomic)□Aneuploidy- addition of one or more chromosomesExtra Sex Hormones- xxy,xyy, xxyy,xxxyCharacteristic of several plant species. □Polyploidy- Multiple copies of the entire genomeNumerical Changes in Chromosomes○SubstitutionsAdditionSubtractionGene Point Mutations- changes in the bases of the DNA or at a single base ( Nucleotide changes ( A C T G)) ○Chemical mutagensi.Spontaneous Mutations during DNA replicationii.Corrections that are not fixed by DNA polymerase( building back DNA that have been separated)iii.Causes of Mutations○Can control the mutation rateGreater change in base over timeMutator Genes○Only changes in the gametes are considered a mutation•Harmful/ lethal1)Minor/ Major2)Produces a protein3)If the genes are recessive it would make it more difficult for the gene to be seen in the phenotypic form but will still be passed to the offspring which could still cause complications within the body.i.Most Mutations are recessive.4)Effect of Mutations•Mutation II Silent Mutations- mutations for quick codon change in amino acidMutated gene- expressed that some fitness within the environmentBeneficial- Increases fitness if an organismProtein Chain Length Modifiers- Start and Stop Codons- tells the RNA polymerase when to begin process and when to endMutations in
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