Chapter 18Classification

Taxonomy– the science of classification

• Carolus Linnaeus’ system:– Uses Latin…descriptive, universal,

“dead” language that never changes– Uses binomial nomenclature

• Two word naming system of Genus & species = scientific name

– Uses hierarchy of categories (taxons) from general to specific:

Domain

Kingdom

Phylum

Class

Order

Family

Genus

Species

Eukarya

Animalia

Chordata

Mammalia

Carnivora

Felidae

Lynx

Lynx rufus

Lynx canadensis

Bobcat Lynx

Taxonomic levels

Kingdom…Phylum…Class…Order…Family…Genus species…(variety) or (breed)

Who am I?

Who am I?

The Puma holds the Guinness record for the animal with the highest number of names. It has more than 40 names in English.

Puma, Mountain lion, Cougar, Panther

Scientific Name:Felis concolor

Comparing related animals

• Lynx canadensis, lynx• Felis concolor, mountain

lion• Felis domesticus, house cat

• Which two are more related? How do you know?

Mountain lion

House catLynx

Human classification:Kingdom Animalia

PhylumChordata

ClassMammalia

OrderPrimates

FamilyHominidae

GenusHomo

speciessapiens

Remember the 2 Cell Types?• Prokaryotic

– Small, simple cells without membrane-bound organelles; i.e. bacteria

• Eukaryotic– Large, complex cells

containing many specialized organelles, nucleus; i.e. plants, animals, protists & fungi

• All living things are divided into groups based on:– Cell types (Prokaryotic vs. Eukaryotic)– Cell structure (cell walls, chloroplasts?)– Number of cells (unicellular vs. multicellular)– Movement (motile or non-motile)– Mode of nutrition (autotroph, heterotroph,

saprobe)

Domains

• Largest , most inclusive group– Archaea: Prokaryotic cells

• 1 kingdom: Archaebacteria– Bacteria: Prokaryotic cells

• 1 kingdom: Eubacteria– Eukarya: Eukaryotic cells

• 4 kingdoms: Protista, Fungi, Plantae, Animalia

Kingdom Archaebacteria • Most live in extreme

environments– Most do not use oxygen to

respire (anaerobic).– Ancestor to eukaryotes

• Unicellular • Cell walls lack peptidoglycan• Can be heterotrophic or

autotrophic• Some motile, others non-

motile• Examples: Halophiles,

methanogens.

Kingdom Eubacteria• Unicellular• Very strong cell

walls (peptidoglycan)

• Autotrophic or heterotrophic

• diverse habitat• Some motile, other

non-motile• Ex: streptococcus,

Escherichia coli

Kingdom Protista• Most are unicellular, few are

multicellular– lacks complex organ systems

• lives in moist environments• diverse metabolism/motility

– Animal-Like– Plant-Like (cellulose,

chloroplasts) – Fungus-Like

• Ex: Amoeba, euglena, slime molds

Fungi overview• Saprobes: decomposes

matter by absorbing materials

• Multicellular (mushrooms) or unicellular (yeast)

• Cell walls (chitin)• Non-motile

Kingdom Plantae• Multicellular• Autotrophic:

Photosynthetic– Cells contain

chloroplasts• Immobile• Cell walls

(cellulose)• Ex: grass, rose

• Multicellular• Mobile (at one point during their lifetime)• Lack cell walls• Diverse habitats• Heterotrophic• Ex: insects, worms, squirrels, birds

Kingdom Animalia

Organism Number Described

Estimated number to be Discovered

Viruses 5,000 about 500,000

Bacteria 4,000 400,000-300 million

Fungi 70,000 1-1.5 million

Protozoans 40,000 100,000-200,000

Algae 40,000 200,000-10 million

Flowering plants 250,000 300,000-500,000

Roundworms 15,000 500,000-1 million

Mollusks 70,000 200,000

Crustaceans 40,000 150,000

Spiders and mites 75,000 750,000-10 million

Insects 950,000 8-100 million

Vertebrates 45,000 50,000

Exit TicketWhich characteristic describes these three organisms?

A) UnicellularB) HeterotrophicC) ProkaryoticD) Phototrophic

How do we identify organisms?

Dichotomous key: system to identify organisms and their scientific names• A key is made up of sets of numbered

statements. • Each set deals with a single characteristic

of an organism, such as leaf shape (toothed or smooth edge) or number of teeth (more than 30 or less than 30).

• It’s kind of like the game 20 questions

Phylogeny

Phylogeny: Studying the evolutionary histories and relationships of organisms

• Cladistics: a phylogenic study that assumes when probable groups of organisms diverged and evolved

Theropods

Allosaurus

Sinornis

Velociraptor

Archaeopteryx

Light bones3-toed foot;

wishboneDown

feathers

Feathers withshaft, veins,and barbs

Flight feathers;arms as long

as legs

Cladograms• “Family tree” that represents evolutionary

relationships (and not just physical appearances)

CLADOGRAM

Fur & MammaryGlands

Jaws

Lungs

Claws or Nails

Feathers

Hagfish Fish FrogLizard

Pigeon

Mouse

Chimp

Bacteria

Protista

AnimaliaPlantae Fungi

EuPro

MultiUni

(Seaweeds)

Nutritional types

Auto(photo) Hetero(absorb) Hetero(ingest)

Evolution and the 6 Kingdoms

What determines evolutionary relationship?

• Anatomy and physiology– Common structures imply a common

ancestor.• Breeding and behavior patterns• Geographic distribution• DNA and biochemistry

DNA comparisons between these plants show almost no difference.