Biol 200B Lecture 2Course IntroductionI. Syllabus and Lecture ScheduleII. Course layouta. Diversity of microbes, protists, fungi, plants, animalsb. Organismal biology (anatomy & physiology) of plants & animals c. EcologyThe Tree of LifeII. Phylogenetic tree of lifea. All organisms connected through similarities in their form and function; passage of genes along branches of treeIII. Reading a phylogenetic treeIV. Speciesa. “unit” of biodiversityV. Form and FunctionThe Tree of LifePhylogenetic tree of life: All organisms are connected through similarities in their form and function; the passage of genes as shown through the branches of the tree- 5-100 million species living today- All organisms on earth are genetically related-suggested by morphological, biochemical, and gene sequence data- Phylogeny of organisms- history of organisms’ lineages as they change; speciation historyReading a Phylogenetic TreeRoot-common ancestor of all species on treeBranchNode-speciationPolytomy-more than one branch emerging from one nodeTaxaSister taxa- come from the same node; each other’s closest relativesOutgroup“one-snip” test- they share a derived trait - branches can be rotated without changing relationships - sisters are not ancestorsThese 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.- unless specified, the time axis is relative, not absolute- groups that evolve later are not “more advanced” than those that evolved earlier on - a phylogeny can be drawn for any set of speciesSpecies:- Reproductively isolated set of population- Independent evolutionary lineage- “unit” of biodiversity Form and Function: an organism’s structure or form is designed or shaped in a way that best fitscertain functionsEx: Thermophilic or “heat loving” lizards are common in North American deserts; fish in Antarctica spend their lives at body temperatures near 1.9o
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