Honors

Biology

Ch. 17

Honors

Biology

Ch. 17

Organizing Life’s

Diversity

Organizing Life’s

Diversity

I. The History of

Classification I. The History of

Classification

Taxonomy:Taxonomy: - the science of identifying, naming,

and classifying organisms

A. Early Classification

Systems A. Early Classification

Systems 1.1. Aristotle:Aristotle:

a. Devised First Classification System

- Animals (red-blooded and bloodless)

- Plants (trees, shrubs, and herbs)

- 2 problems: 1) superficial categories2) used common names

B.Disadvantages of Common

Names:B.Disadvantages of Common

Names:1.Confusing

- ex. mountain lion, cougar, puma, panther, catamount

Puma concolorPuma concolor

2.2.MisleadingMisleading- ex. starfish, jellyfish, cuttlefish,

crawfish, silverfish

3.3.Language ProblemsLanguage Problems- local names- names used by different languages- some organisms have no common name

Microplitis demolitorMicroplitis demolitor

2. Carolus Linnaeus 2. Carolus Linnaeus - developed

modern classification system

- Swedish botanist (1700’s)

- 2 important innovations:

a.Binomial Nomenclaturea.Binomial Nomenclature- two-word naming

system:genus & species

- gives a unique, universal name for every species

Carolus LinnaeusCarolus Linnaeus

Honey Bee

Honey Bee

Apis pubescens, thorace subgriseo, abdomine fusco, pedibus posticis glabris, utrinque margine ciliatus

Apis mellifera

Apis mellifera

1) Genus: - 1st word, small group- usually a Latin noun, capitalized

2) Species:- 2nd word, particular type- Latin adjective, lower case

3)Examples:3)Examples:- Homo sapiens humans- Tyrannosaurus rex

3)Examples:3)Examples:- Acer macrophyllum bigleaf maple- Acer rubrum red maple- Acer saccharum sugar maple

Acer saccharum

Acer saccharum

Acer rubrumAcer

rubrum

Acer circinatum

Acer circinatum

Acer pennsylvaticum

Acer pennsylvaticum

3)Examples:3)Examples:- Sequoia gigantum giant sequoia- Tsuga heterophyllum western hemlock- Pseudotsuga menziesii Douglas-fir

EukaryaAnimalia

Chordata

Mammalia

Carnivora

Canidae Canis

lupus

DomainKingdom

PhylumClassOrderFamilyGenusSpecies

b. Hierarchy of Classification Groupings

b. Hierarchy of Classification Groupings

DidKing

Phillipcome

oftenfor

gingersnaps?

EukaryaAnimalia

Chordata

Mammalia

Carnivora

Canidae Canis

lupus

DomainKingdom

PhylumClassOrderFamilyGenusSpecies

b. Hierarchy of Classification Groupings

b. Hierarchy of Classification Groupings

Hierarchy of

Taxa

Hierarchy of

Taxa

II. Taxonomy TodayII. Taxonomy Today- Classification systems change

constantly.

- Taxonomists do not always agree on how to classify organisms.

A.Determining SpeciesA.Determining Species1. Typological Species Concept

- a group of organisms that are physically similar to each other

2. Biological Species Concept 2. Biological Species Concept - a group of organisms

that is able to interbreed and produce fertile offspring in a natural setting

- cannot be used with extinct or asexual organisms

Similarity between different speciesSimilarity between different species

Diversity within a speciesDiversity within a species

3. Phylogenetic Species Concept 3. Phylogenetic Species Concept

- defines a species as a set of organisms with a unique genetic history

B.CharactersB.Characters- inherited features (morphological

or biochemical) that vary among organisms

1. Morphological Characters 1. Morphological Characters - similarities indicate common

ancestry- include homologous structures:

different functions but have similar underlying anatomy

- does not include analogous structures: similar functions but different underlying anatomy

Eastern MoleEastern Mole

Marsupial ‘Mole’Marsupial ‘Mole’

2. Biochemical Characters 2. Biochemical Characters - The greater

the similarities in certain compounds (DNA, proteins, etc.), the more closely related organisms are.

Species

Human

Rhesus monkey

Mouse

Chicken

Frog

Lamprey14%

54%

69%

87%

95%

100%

Percent of Amino Acids That AreIdentical to the Amino Acids in aHuman Hemoglobin Polypeptide

Comparison of a Protein Found in Diverse Vertebrates

Comparison of a Protein Found in Diverse Vertebrates

A Molecular Homology

A Molecular Homology

3. Molecular “Clock” 3. Molecular “Clock” - Mutations occur randomly and

accumulate over time.- Mutations that

don’t affect survival can be

used to estimate time.

The Constant Rate of Evolution of the α-globin

The Constant Rate of Evolution of the α-globin

C.Phylogenetic Reconstruction

C.Phylogenetic Reconstruction - Phylogeny is

the evolutionary history of a species.

Phylogeny of WhalesPhylogeny of Whales

Leopard

Hair

Amniotic egg

Four walking legs

Hinged jaws

Vertebral column

Turtle

Salamander

Tuna

Lamprey

Lancelet (outgroup)

Phylogenetic Tree of ChordatesPhylogenetic Tree of Chordates

1. Character Types1. Character Types- Ancestral characters are

shared by ancestral organism and all of its descendents.

- Derived characters are shared by one group of organisms but not the ancestor.

2. Cladograms (Phylogenetic Tree) 2. Cladograms (Phylogenetic Tree)

- a branching diagram that represent the proposed phylogeny of a group of

organisms

Phylogenetic Tree of Dinosaurs

Phylogenetic Tree of Dinosaurs

Ursininae Tremarclinae

Ailuropodinae

Ailuridae

Musteloidae

Procyonidae

Caniformia

Ursidae

Phylogeny of

Bears

- Most scientists today use the 3 domain system to classify organisms:Bacteria, Archaea, and Eukarya.

III. Domains and KingdomsIII. Domains and Kingdoms

Fungi

EUKARYA

Trypanosomes

Green algaeLand plants

Red algae

ForamsCiliates

Dinoflagellates

Diatoms

Animals

AmoebasCellular slime molds

Leishmania

Euglena

Green nonsulfur bacteria

Thermophiles

Halophiles

Methanobacterium

Sulfolobus

ARCHAEA

COMMONANCESTOR

OF ALLLIFE

BACTERIA

(Plastids, includingchloroplasts)

Greensulfur bacteria

(Mitochondrion)

Cyanobacteria

ChlamydiaSpirochetes

The Three Domains

of Life

A.Domain BacteriaA.Domain Bacteria- includes the

kingdom Eubacteria

- prokaryotes whose cell walls contain peptidoglycan

B. Domain ArchaeaB. Domain Archaea- Prokaryotes that

represent an ancient form of life

- more closely related to our eukaryotic ancestors

- called extremophiles because they can live in extreme environments

C.Domain EukaryaC.Domain Eukarya- includes all eukaryotes - contains:

Kingdom ProtistaKingdom PlantaeKingdom FungiKingdom Animalia

1.Kingdom Protista1.Kingdom Protista- eukaryotic organisms - unicellular, colonial, or

multicellular

2.Kingdom Plantae2.Kingdom Plantae- photosynthetic multicellular

eukaryotes- have cell walls made of cellulose- nonmotile

3. Kingdom Fungi3. Kingdom Fungi- unicellular or multicellular

eukaryote- heterotrophic (absorb nutrients)- have cell walls made of chitin- nonmotile

3. Kingdom Fungi3. Kingdom Fungi- unicellular or multicellular

eukaryote- heterotrophic (absorb nutrients)- have cell walls

made of chitin- nonmotile

4.Kingdom Animalia4.Kingdom Animalia- heterotrophic, multicellular

eukaryotes- complex organ systems - motile- obtain

food by ingestion

TheTheTheThe

EndEndEndEnd

- Order Carnivora

Linking Classification and Phylogeny

Linking Classification and Phylogeny

Species

Canislupus

Panthera pardus

Taxideataxus

Lutra lutra

Canislatrans

Order Family Genus

Carn

ivora

Felid

aeM

ustelid

aeC

anid

ae

Can

isL

utra

Taxid

eaP

anth

era

A Phylogenetic Tree of Birds and Their Close

Relatives

A Phylogenetic Tree of Birds and Their Close

Relatives

Commonancestor ofcrocodilians,dinosaurs,and birds

Birds

Lizardsand snakes

Crocodilians

Ornithischiandinosaurs

Saurischiandinosaurs

Phylogeny of Horses

Phylogeny of Horses

Recent(11,500 ya)

Pleistocene(1.8 mya)

Pliocene(5.3 mya)

Miocene(23 mya)

Oligocene(33.9 mya)

Eocene(55.8 mya)

EquusHippidion and other genera

Nannippus

PliohippusNeohipparionHipparion

Sinohippus MegahippusCallippus

Archaeohippus

Merychippus

Parahippus

HypohippusAnchitherium

Miohippus

Mesohippus

Epihippus

Orohippus

Paleotherium

Propalaeotherium

Pachynolophus

GrazersBrowsers

Key

Hyracotherium