Chapter 17Chapter 17ClassificationClassification

Taxonomy:Taxonomy: names and groups names and groups organisms according to their organisms according to their

characteristics and evolutionary historycharacteristics and evolutionary history

History of ClassificationHistory of Classification Over 1,750,000 species have been Over 1,750,000 species have been

given names.given names.

There are 10 million yet to be There are 10 million yet to be discovered!discovered!

99% of all plant and animal species 99% of all plant and animal species that have ever existed are now extinct, that have ever existed are now extinct, most left no fossil record.most left no fossil record.

Early Systems of ClassificationEarly Systems of Classification Aristotle—He divided things into animals and Aristotle—He divided things into animals and

plants.plants.

Animals—classified as: Animals—classified as: -Land dwellers-Land dwellers

-Water dwellers-Water dwellers-Air dwellers-Air dwellers

Plants—Three categories based on stemsPlants—Three categories based on stems

Problems with Early SystemsProblems with Early Systems Common namesCommon names - there are local differences and - there are local differences and

they can be unclear.they can be unclear.

Names were polynomial - names used descriptive Names were polynomial - names used descriptive terms, so some were thirteen or more words long. terms, so some were thirteen or more words long.

The term for a honey bee:The term for a honey bee:-Apis pubescences, thorace, subgriseo, abdomine -Apis pubescences, thorace, subgriseo, abdomine fusco, pedibus posticis glabris untrinque margine fusco, pedibus posticis glabris untrinque margine ciliatis.ciliatis.

Carolus LinnaeusCarolus Linnaeus(Sweden, 1750’s)(Sweden, 1750’s)

Hierarchical Hierarchical categoriescategories - using - using morphology.morphology.

BinomialBinomial system - system - two namestwo names

There are seven levels of classification:There are seven levels of classification:

Levels of ClassificationLevels of Classification

1.1. Kingdom-Kingdom-largest (six kingdoms)-least specificlargest (six kingdoms)-least specific2.2. PhylumPhylum3.3. ClassClass4.4. OrderOrder5.5. Family Family 6.6. Genus Genus 7.7. Species-Species-smallest-(most specific)smallest-(most specific)

Kingdom

Phylum

Class

Order

Family

Genus

Species

From biggest to smallest:1. Kingdom – compare to a country

2. Phylum –compare to a state

3. Class – compare to a county

4. Order – compare to a town

5. Family - compare to a neighborhood

6. Genus - compare to a street

7. Species – compare to house number

Classifying people!

1. Kingdom – Animal2. Phylum – Chordate (backbones)3. Class – mammal4. Order - Primates5. Family - Hominidae6. Genus – Homo (man)7. Species –Sapiens (wise)

Scientific Name of people: Homo sapien

How do I remember the order?

* Use the sentence:

Kings Play Chess On Funny Green Squares

Binomial NomenclatureBinomial Nomenclature

Scientific namesScientific names - - Genus species, Genus species, genus genus name is capitalized, both are italicized.name is capitalized, both are italicized.

E. coli: E. coli: sometimes genus name is abbreviated sometimes genus name is abbreviated (Escherichia coli)(Escherichia coli)

Species sometimes broken down more Species sometimes broken down more ((varietiesvarieties-botanists, -botanists, subspeciessubspecies-zoologists)-zoologists)

Binomial NomenclatureBinomial Nomenclature Continued Continued

LatinizedLatinized—often descriptive or in honor —often descriptive or in honor of a person (discoverer) or place.of a person (discoverer) or place.

PhylogenyPhylogeny—evolutionary history is now —evolutionary history is now considered.considered.

MorphologyMorphology-based on genes—so most of -based on genes—so most of Linnaeus’s work is still accurate.Linnaeus’s work is still accurate.

Rhinecanthus aculeatusRhinecanthus aculeatus

- Hawaii – Huma Huma Nuka Nuka Apua’a- Hawaii – Huma Huma Nuka Nuka Apua’a- Other Places - Picasso Triggerfish- Other Places - Picasso Triggerfish

Acer Acer Acer Acer rubrum rubrum saccharumsaccharum

Modern Phylogenetic TaxonomyModern Phylogenetic Taxonomy SystematicsSystematics - - diversity of life organized diversity of life organized

within the context of evolution.within the context of evolution.

Phylogenetic treePhylogenetic tree - - represents hypothesis of represents hypothesis of evolutionary linkage between organismsevolutionary linkage between organisms

Compare morphology of an organism to fossil Compare morphology of an organism to fossil record or other living species.record or other living species.

Compare DNACompare DNA

Compare macromoleculesCompare macromolecules - cytochrome c - cytochrome c and hemoglobin beta-chainand hemoglobin beta-chain

The fossil recordThe fossil record - usually incomplete - usually incomplete

MorphologyMorphology - homologous structures--the - homologous structures--the species that have them are related.species that have them are related.

- Embryological patterns of development- Embryological patterns of development

Chromosomes and MacromoleculesChromosomes and MacromoleculesMolecular clockMolecular clock - differences in the amino - differences in the amino

acid chains, RNA sequences, and DNA acid chains, RNA sequences, and DNA sequences can tell how long ago two things sequences can tell how long ago two things were related.were related.

CladisticsCladistics - Organization based on - Organization based on evolutionary relationshipsevolutionary relationships- - Derived character Derived character - - feature that apparently feature that apparently

evolved only within the group (feathers)evolved only within the group (feathers)More derived characters=more common ancestry.More derived characters=more common ancestry.

CladogramsCladograms

Ancestry diagramAncestry diagram - shows evolutionary relationships. - shows evolutionary relationships.

Modern System of ClassificationModern System of Classification

Six kingdom systemSix kingdom systemArchaebacteria:Archaebacteria: unicellular prokaryotes, unicellular prokaryotes,

harsh environments.harsh environments.

Eubacteria:Eubacteria: common form of bacteria, common form of bacteria, circular chromosomes, most are aerobic.circular chromosomes, most are aerobic.

Protista:Protista: eukaryotesm mostly unicelluar, no eukaryotesm mostly unicelluar, no complex tissues or systems.complex tissues or systems.

Fungi:Fungi: heterotrophic eukaryotes, heterotrophic eukaryotes, unicellular and multicellular, absorb unicellular and multicellular, absorb nutrients, 100,000 species.nutrients, 100,000 species.

Plantae:Plantae: Eukaryotes, multicellular, most Eukaryotes, multicellular, most are autotrophic—photosynthesis, 350,000 are autotrophic—photosynthesis, 350,000 species.species.

Animalia:Animalia: Eukaryotes, multicellular, Eukaryotes, multicellular, heterotrophic, most have symmetrical heterotrophic, most have symmetrical bodiesbodies

Archaebacteria

Eubacteria

Protists

Fungi

PlantsPlants

Animals

Three Domain SystemThree Domain System

Based on Ribosomal RNA (rRNA)Based on Ribosomal RNA (rRNA)

Domain Archaea– archaebacteriaDomain Archaea– archaebacteria

Domain Bacteria—eubacteriaDomain Bacteria—eubacteria

Domain Eukarya—protists, fungi, Domain Eukarya—protists, fungi, plants and animals.plants and animals.