Biology WarmUp: Copy ALL of these assignments into your binder Including dates, WarmUps, InClass assignments AND page numbers! April 20 WarmUp: Agenda InClass: Most missed questions Poster Presentations: Affect of Latitude on Climate&Community Interactions InClass: Guided Reading 18.2 In Class: How is a Cladogram Constructed? P453 Homework: Read 18.1 April 21(even)-22(odd) WarmUp: Most-missed questions part 2 InClass: Using Dichotomous Keys Part A p462 Homework: Read 18.2 April 23(even)-24(odd) WarmUp: Classification InClass: Using Dichotomous Keys Part B p462 InClass: SVHS Tree key Homework: Read 18.3 Biology Chapter 18 Unit 18.1 Unit 18.2 Unit 18.3 Finding Order in Diversity 1.5 Million Species have been named. There may be 2 or 100 million more! Why Classify? To study such diversity of life biologists use a classification system to •name and •group organisms in a •logical manner Why Classify? To study such diversity of life biologists use a classification system to: name and group organisms in a logical manner •Taxonomy- assigning each organism a universally accepted name •Grouping- classification provides smaller and smaller groups in order to organize the diversity Teachers- biology teachers- IB Biology teachers Why Classify? •Taxonomy- assigning each organism a universally accepted name •grouping- classification provides smaller and smaller groups in order to organize the diversity Teachers- biology teachers- IB Biology teachers Assigning Scientific Names Mountain lion? Puma? Cougar? Panther? Why Classify? •Taxonomy- assigning each organism a universally accepted name •grouping- classification provides smaller and smaller groups in order to organize the diversity Teachers- biology teachers- IB Biology teachers Assigning Scientific Names Felis concolor To avoid confusion caused by regional names, biologists use a classification system to group organisms in a logical manner and assign names Assigning Scientific Names Felis concolor To avoid confusion caused by regional names, biologists use a classification system to group organisms in a logical manner and assign names Early Efforts at Naming Used physical characteristics Oak with deeply divided leaves that have no hairs on their undersides and no teeth around their edges. Names were too long and Difficult to standardize Early Efforts at Naming Used physical characteristics Names were too long and Difficult to standardize Binomial Nomenclature 18th century Swedish botanist, Linnaeus In binomial nomenclature is species is assigned a two-part scientific name Binomial Nomenclature 18th century Swedish botanist, Linnaeus In binomial nomenclature each species is assigned a two-part scientific name •Always written in italics •First word is capitalized •second word is lowercased Ursus arctos Genus - group of closely related species Species - unique to each species in genus. Latinized characteristic QuickTime™ and a TIFF (Uncompressed) decompressor are needed to see this picture. Ursus arctos (horribilis) Binomial Nomenclature •Always written in italics •First word is capitalized •second word is lowercased Genus - group of closely related species Species - unique to each species in genus. Latinized characteristic Linnaeus's System of Classification Linnaeus’ system uses seven taxonomic categories species genus family order class phylum Linnaeus's System of Classification Linnaeus’ system uses seven taxonomic categories species breeding population genus group of closely related species family genera that share many characteristics i.e.. Ursidae order broad category of similar families i.e.. Carnivora class similar orders i.e.. Mammalia phylum very different organisms that share some important characteristics i.e.. Chordata Kingdom Linnaeus named just two, plants and animals Linnaeus's System of Classification Grizzly bear Black bear Giant panda Red fox KINGDOM Animalia Abert squirrel PHYLUM Chordata CLASS Mammalia ORDER Carnivora FAMILY Ursidae GENUS Ursus SPECIES Ursus arctos Coral snake Sea star 18.2 Modern Evolutionary Classification Problems With Traditional Classification How would Linnaeus classify a dolphin? with fish? or with mammals? What about a barnacle, limpet, and crab? Evolutionary Classification Darwin’s theory of evolution changed classification Biologists now group organisms according to evidence of common evolutionary descent not just physical similarities. 18.2 Modern Evolutionary Classification Problems With Traditional Classification How would Linnaeus classify a dolphin? with fish? or with mammals? Conical Shells Appendages What about a barnacle, limpet, and crab? Crab TRADITIONAL CLASSIFICATION Barnacle Limpet Evolutionary Classification Darwin’s theory of evolution changed classification Biologists now group organisms according to evidence of common evolutionary descent not just physical similarities. species in the same genus should be more closely related to each other than to species of other genera. Genera in the same family should be more closely related to each other than to genera in other families Evolutionary Classification species in the same genus should be more closely related to each other than to species of other genera. Genera in the same family should be more closely related to each other than to genera in other families This is what leads to a rethinking of how to classify crabs, limpets, and barnacles. Cladograms and Cladistic Analysis Cladograms and Cladistic Analysis New characteristics that arise as a lineage changes over time. Relatively newer characteristics are referred to as derived characters Cladograms show evolutionary relationship among groups of organisms Cladograms and Analysis New characteristics that ariseCladistic as a lineage changes over time. Relatively newer characteristics are referred to as derived characters Cladograms show evolutionary relationship among groups of organisms Conical Shells Crustaceans Appendages Gastropod Crab Barnacle Limpet Crab Barnacle Limpet Molted exoskeleton TRADITIONAL CLASSIFICATION Segmentation CLADOGRAM Tiny freeswimming larva Cladograms and Cladistic Analysis New characteristics that arise as a lineage changes over time. Relatively newer characteristics are referred to as derived characters Cladograms show evolutionary relationship among groups of organisms QuickLab How is a cladogram constructed? p453 Similarities in DNA and RNA Very different organisms have common traits ALL use DNA and RNA much of which is VERY similar The molecular similarities of organisms’ genes can be used to help determine classification. This has changed many classifications American Vultures look like African and Asian Vultures and had been classified together. DNA evidence backed up other evidence classifying them with storks Similarities in DNA and RNA Very different organisms have common traits ALL use DNA and RNA much of which is VERY similar The molecular similarities of organisms’ genes can be used to help determine classification. This has changed many classifications American Vultures look like African and Asian Vultures and had been classified together. DNA evidence backed up other evidence classifying them with storks Molecular Clocks Comparison of DNA of related species shows difference in DNA. Comparison of differences can show how long ago organisms diverged Biology Warm Up: Cladistics 1. Copy the cladogram onto your paper. According to the cladogram, do flowering plants share a more recent common ancestor with ferns or mosses? Explain. 2. What derived characteristic do flowering plants, cone-bearing plants and ferns all have in common? 3. Based on the cladogram, which type of plants have vascular tissue and produce seeds, but do not have either flowers or fruit? Biology Warm Up: Cladistics 1. According to the cladogram, do flowering plants share a more recent common ancestor with ferns or mosses? Explain. Flowering plants share a more recent common Ancestor with ferns than with mosses Biology Warm Up: Cladistics 2. What derived characteristic do flowering plants, conebearing plants and ferns all have in common? Flowering plants, cone-bearing plants, and ferns all have vascular tissue Biology Warm Up: Cladistics 3. Based on the cladogram, which type of plants have vascular tissue and produce seeds, but do not have either flowers or fruit? Cone-bearing plants have vascular tissue and produce seeds But do not produce flowers or fruit. 18.3 Kingdoms and Domains The “Tree of Life” Linnaeus gave us two kingdoms, plants and animals Where to put protists and bacteria? What about fungi? What about prokaryotes? Resulting five-kingdom system: Monera Protista Fungi Plantae Animalia Recently, Monera was split into two groups: Eubacteria Archaebacteria Protista Fungi Plantae Animalia See the table on page 458 of the text 18.3 Kingdoms and Domains The “Tree of Life” Recently, Monera was split into two groups: Eubacteria Archaebacteria Protista Fungi Plantae Animalia See the table on page 458 of the text Three-Domain System New taxonomic category - DOMAIN larger than kingdom Bacteria - Eubacteria Archae- Archaebacteria Eukarya- Protists, Fungi, Plants, and Animals Three-Domain System New taxonomic category - DOMAIN larger than kingdom Bacteria - Eubacteria Archae- Archaebacteria Eukarya- Protists, Fungi, Plants, and Animals Domain Bacteria Unicellular Prokaryotic Thick rigid walls - peptidoglycan Domain Archae Unicellular Prokaryotic Most are anaerobic No peptidoglycan Domain Eukarya All organisms that have a nucleus Protista Organisms that are not Fungi, Plants, or Animals Many, but not all are unicellular Some are photosynthetic Fungi Heterotrophs - feed on dead or decaying matter Secrete digestive enzymes Most are multicellular Plantae multicellular plants - photosynthetic Nonmotile Have cell walls Animalia Multicellular heterotrophic Motile at least part of their life