April 20WarmUp: AgendaInClass: Most missed questionsPoster Presentations: Affect of Latitude on Climate&Community Interactions

InClass: Guided Reading 18.2In Class: How is a Cladogram Constructed? P453Homework: Read 18.1April 21(even)-22(odd)WarmUp: Most-missed questions part 2InClass: Using Dichotomous Keys Part A p462Homework: Read 18.2April 23(even)-24(odd)WarmUp: ClassificationInClass: Using Dichotomous Keys Part B p462InClass: SVHS Tree keyHomework: Read 18.3

Biology WarmUp: Copy ALL of these assignments into your binderIncluding dates, WarmUps, InClass assignments AND page numbers!

BiologyChapter 18

Unit 18.3Unit 18.2Unit 18.1

Finding Order in Diversity1.5 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 diversityTeachers- 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 diversityTeachers- biology teachers- IB Biology teachers

Assigning Scientific NamesMountain 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 diversityTeachers- biology teachers- IB Biology teachers

Assigning Scientific NamesFelis concolorTo avoid confusion caused byregional names, biologistsuse a classification system togroup organisms in a logicalmanner and assign names

Assigning Scientific NamesFelis concolorTo avoid confusion caused by regional names, biologists use a classification system to group organisms in a logical manner and assign names

Early Efforts at NamingUsed physical characteristicsOak with deeply divided leaves that have no hairs on their undersides and no teeth around their edges.Names were too long andDifficult to standardize

Early Efforts at NamingUsed physical characteristicsNames were too long andDifficult to standardize

Binomial Nomenclature18th centurySwedish botanist, LinnaeusIn binomial nomenclature is species is assigned a two-part scientific name

Binomial Nomenclature18th centurySwedish botanist, LinnaeusIn binomial nomenclature each species is assigned a two-part scientific name•Always written in italics•First word is capitalized•second word is lowercasedUrsus arctosGenus - group of closely related speciesSpecies - unique to each species in genus. Latinized characteristic

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Ursus arctos (horribilis)

Binomial Nomenclature•Always written in italics •First word is capitalized•second word is lowercasedGenus - group of closely related speciesSpecies - unique to each species in genus. Latinized characteristicLinnaeus's System of ClassificationLinnaeus’ system uses seven taxonomic categoriesspeciesgenusfamilyorder classphylumkingdom

Linnaeus's System of ClassificationLinnaeus’ system uses seven taxonomic categoriesspecies breeding populationgenus group of closely related speciesfamily 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 Abert squirrel

Coral snake

Sea starKINGDOM Animalia

PHYLUM Chordata

CLASS Mammalia

ORDER Carnivora

FAMILY Ursidae

GENUS Ursus

SPECIES Ursus arctos

18.2 Modern Evolutionary Classification

Problems With Traditional ClassificationHow would Linnaeus classify a dolphin?

with fish? or with mammals?What about a barnacle, limpet, and crab?Evolutionary ClassificationDarwin’s theory of evolution changed classificationBiologists now group organisms according to evidence of common evolutionary descent not just physical similarities.

18.2 Modern Evolutionary Classification

Problems With Traditional ClassificationHow would Linnaeus classify a dolphin?

with fish? or with mammals?What about a barnacle, limpet, and crab?

TRADITIONAL CLASSIFICATION

Appendages Conical Shells

Crab Barnacle Limpet

Evolutionary ClassificationDarwin’s theory of evolution changed classificationBiologists 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 familiesThis is what leads to a rethinking of how to classify crabs, limpets, and barnacles.

Cladograms and Cladistic Analysis

Cladograms and Cladistic AnalysisNew characteristics that arise as a lineage changes over time.Relatively newer characteristics are referred to as derived charactersCladograms show evolutionary relationship among groups of organisms

TRADITIONAL

CLASSIFICATIONCLADOGRAM

Appendages Conical Shells

Crab Barnacle Limpet Crab Barnacle Limpet

Crustaceans Gastropod

Molted exoskeleton

Segmentation Tiny free-swimming larva

Cladograms and Cladistic AnalysisNew characteristics that arise as a lineage changes over time.Relatively newer characteristics are referred to as derived charactersCladograms show evolutionary relationship among groups of organisms

Cladograms and Cladistic AnalysisNew characteristics that arise as a lineage changes over time.Relatively newer characteristics are referred to as derived charactersCladograms show evolutionary relationship among groups of organisms

QuickLabHow is a cladogram constructed? p453

Similarities in DNA and RNAVery different organisms have common traitsALL use DNA and RNA

much of which is VERY similarThe molecular similarities of organisms’ genes can be used to help determine classification.This has changed many classificationsAmerican 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 RNAVery different organisms have common traitsALL use DNA and RNA

much of which is VERY similarThe molecular similarities of organisms’ genes can be used to help determine classification.This has changed many classificationsAmerican Vultures look like African and Asian Vultures and had been classified together.DNA evidence backed up other evidence classifying them with storks

Molecular ClocksComparison 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 commonAncestor with ferns

than with mosses

Biology Warm Up: Cladistics 2. What derived characteristic do flowering plants, cone-bearing plants and ferns all have in common?

Flowering plants, cone-bearing plants, and ferns all have vascular tissue

Biology Warm Up: Cladistics3. Based on the cladogram, which type of plants have vascular tissue and produce seeds, but do not have either flowers or fruit?

Cone-bearing plantshave vascular tissue and produce seeds

But do not produce flowers orfruit.

18.3 Kingdoms and Domains

The “Tree of Life”Linnaeus gave us two kingdoms, plants and animalsWhere to put protists and bacteria?What about fungi? What about prokaryotes?Resulting five-kingdom system:Monera Protista Fungi Plantae AnimaliaRecently, Monera was split into two groups:Eubacteria ArchaebacteriaProtista Fungi Plantae AnimaliaSee 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 ArchaebacteriaProtista Fungi Plantae AnimaliaSee the table on page 458 of the text

Three-Domain SystemNew taxonomic category - DOMAIN

larger than kingdomBacteria - EubacteriaArchae- ArchaebacteriaEukarya- Protists, Fungi, Plants, and Animals

Three-Domain SystemNew taxonomic category - DOMAIN

larger than kingdomBacteria - EubacteriaArchae- ArchaebacteriaEukarya- Protists, Fungi, Plants, and AnimalsDomain BacteriaUnicellularProkaryoticThick rigid walls - peptidoglycanDomain ArchaeUnicellular Prokaryotic Most are anaerobicNo peptidoglycan

Domain EukaryaAll organisms that have a nucleusProtista Organisms that are not Fungi, Plants, or AnimalsMany, but not all are unicellularSome are photosyntheticFungi Heterotrophs - feed on dead or decaying matterSecrete digestive enzymesMost are multicellularPlantae multicellular plants - photosyntheticNonmotile Have cell wallsAnimalia Multicellular heterotrophicMotile at least part of their life