BCOR 012 1st Edition Lecture 8Outline of Last Lecture I. Definition of phylogeny and phylogeny dataII. Hierarchy of LifeIII. Key Points about PhylogeniesIV. Shared CharactersV. Clades & phyletic groupsVI. Types of characters used for Phylogenetic TreesOutline of Current Lecture I. Microevolution and macroevolution connectionII. Major Characters used for Phylogenetic trees cont.III. Homology vs. AnalogyIV. Brief Lecture Review of Past LecturesV. Introduction to Chapter 25 – Cell TheoryCurrent Lecture- Microevolution -> macroevolution. Question: How is a speciation event (macroevolution)influenced by the four forces of microevolution?o A pre- or postzygotic barrier is present preventing gene flowo Each species change is due to natural selection – pushes separation of species, a possible beneficial mutation to one of the species being createdo Genetic drift (bottleneck and founder effect)Major Types of Characters Used to Construct Phylogenetic Trees- Shared ancestral characters – found in a clade on a tree that is being analyzed and seen in older clades- Shared derived characters – evolutionary novelties to a particular cladeo Both are relative to the taxa we are analyzing and looking at- Depending on the row of characters, in a table of characters, determines if the character is a shared derived character or a shared ancestral character- Out-group – a taxon that is known to have diverged before the lineage that contains the group of taxa being studied- In-group – the group of taxon being studiedThese notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.- Shared ancestral characters of the whole group of taxa is the shared trait that is found furthest to the left on a phylogenetic tree- Phylogenies are inferred from morphological and molecular data- Morphological and genetic similarities in species are due to homologiesHomology vs. Analogy- Homology – similarity in different species due to a shared ancestry- Analogy – similarity in different species due to CONVERGENT evolution- Analogous structures are NOT helpful when making trees for the organisms are NOT closely related- Only homologous structures are useful in making phylogenetic treesBrief Review of Past Lectures- Variation is what a population must contain in order for evolution to occur, otherwise the population will remain the same always.- Maximum likelihood is used to determine best phylogenetic tree- Natural selection is a directed change in a population (or species) to make a better fit species- Sources of variation (mutation, recombination, sexual reproduction) are different than the mechanisms of evolution- Polyploidy in animal kingdom is rare and usually leads to an unviable organismo Plants can handle being polyploidy for they reproduce differently than animals and can reproduce both asexually and sexually- Polyploidy affects sympatric speciationChapter 25 – History of LifeWe still haven’t answered the question of “how did life arise from non-life?”Cell Theory – cells are an organism’s basic unit of structure and functionCell Theories 3 Components:I. Life cannot exist beneath the level of the cellII. All organisms are composed of cellsIII. All cells arise from preexisting cells via cell divisionA cell contains 4 biological molecules:I. CarbohydratesII. ProteinsIII. Nucleic Acid (DNA & RNA)IV. LipidsPossible Processes that may have produced the 1st cells:I. Abiotic synthesis of small organic moleculesII. Small molecules joined together to form macromoleculesIII. Formation of proto-cells – precursor of first cellIV. Origin of replication molecules (RNA) made inheritance possiblea. It is hypothesized that RNA came before