Classification

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It’s alive

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• Evaluate the history, purpose, and methods of taxonomy.

Section Objectives:

• Explain the meaning of a scientific name (binominal nomenclature).

• Show the levels of organization (taxa).

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Classification • The grouping of objects or

information based on similarities.

Cat Frog

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Classification

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• Taxonomy (tak SAH nuh mee)

• The branch of biology that groups and names organisms based on studies of their different characteristics.

How Classification Began

Mother tiger raise piglets after cubs die.

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Taxonomists• Biologists who study taxonomy.

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Aristotle • Greek – 384 - 322

B.C.

• First to develop a biological classification system.

• Classified things as either a plant or an animal.

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• He grouped animals according to various characteristics, including their habitat and physical differences.

• He subdivided plants into three groups, herbs, shrubs, and trees, depending on the size and structure of a plant.

Aristotle’s system

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• He subdivided plants into three groups, herbs, shrubs, and trees, depending on the size and structure of a plant.

Aristotle’s system

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• As time passed, more organisms were discovered and some did not fit easily into Aristotle’s groups, but many centuries passed before Aristotle’s system was replaced.

Aristotle’s system

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Linnaeus

• Swedish - (1707 - 1778)

• Based his classification system on physical and structural similarities.

• As a result, the groupings revealed the relationships of the organisms.

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Example• Bats fly but they produce milk

for their young. • [Are they a bird or a mammal?]

• Answer:• They are Mammals

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Linnaeus

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• Evolutionary relationships are determined on the basis of similarities in structure, breeding behavior, geographical distribution, chromosomes, and biochemistry.

How are evolutionary relationships determined?

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• Structural similarities among species reveal relationships.

• The presence of many shared physical structures implies that species are closely related and may have evolved from a common ancestor.

Structural similarities

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Evolutionary Relationships

• Are determined by similarities in structure, breeding behavior, geographical distribution, chromosomes, and biochemistry (DNA).

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• For example, plant taxonomists use structural evidence to classify dandelions and sunflowers in the same family, Asteraceae, because they have similar flower and fruit structures.

Structural similarities

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• Taxonomists observe and compare features among members of different taxa and use

this information to infer their evolutionary history.

Similarities

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Classifying Diversity

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Grizzly bear Black bear Giant panda

Red fox Abert squirrel

Coral snake

Sea star

KINGDOM Animalia

PHYLUM Chordata

CLASS Mammalia

ORDER Carnivora

FAMILY Ursidae

GENUS Ursus

SPECIES Ursus arctos

Section 18-1

General

Specific

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Classification of Organisms

Kingdom

Phylum / Division

Class

Order

Family

Genus

Species

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• Compare the appearance of a lynx, Lynx rufus, a bobcat, Lynx canadensis, and a mountain lion, Panthera concolor.

LynxMountain

lionBobcat

Taxonomic rankings

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Domain

Kingdom

Phylum

Class

Order

Family

Genus

Species

Eukarya

Animalia

Chordata

Mammalia

Carnivora

Felidae

Lynx

Lynx rufus

Lynx canadensis

Bobcat Lynx

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What are the taxa they all have in common?

Kingdom, Phylum, Class and Order

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Binomial nomenclature(Scientific Name)

• Developed by Linnaeus.

• The first word used identifies the genus of the organism.

• The second word, which often describes a characteristic of the organism.

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• consists of a group of similar species.

Genus (JEE nus) (plural, genera)

Just because they look alike it doesn’t make them alike.

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Latin• Is the most common language of

scientific names.

aranea : s

pider's w

eb

canis : dog.

cavus : hole, pit

claudus : lamecontra : (+ acc.) against

deco

r : b

eaut

y, g

race

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Scientific Names • Should be italicized in print and

underlined when handwritten.

• The first letter of the genus name is uppercase, but the first letter of the descriptive name is lowercase.

Passer domesticus

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How did Aristotle group organisms such as birds, bats, and insects?

D. by their homologous structures

C. by their common species

B. by their analogous structures

A. by their common genus

Question 1

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The answer is B.

The organisms were grouped together because of their wings, which, in this case, are analogous structures.

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Which taxon contains the fewest species?

D. phylum

C. order

B. family

A. genus

The answer:

Question 2

A, genus.

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What is the difference between “classification” and “taxonomy?”

AnswerClassification is the grouping of objects or information based on similarities. Taxonomy is the branch of biology that classifies and names organisms based on their different characteristics.

Question 3

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What are the two parts that make up binomial nomenclature?

AnswerBinomial nomenclature comprises a genus name followed by a specific epithet.

Question 4

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Classify the following based on function.

• Desk• Chair• Calculator• Stool• Bookcase• Computer• lights • T.V.

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6 Kingdoms

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6 Kingdoms • Eubacteria • Archaebacteria

• Animals• Protists• Fungi• Plants

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Bacteria• All bacteria are • Unicellular• Prokaryotic• They were probably the first

organisms on the earth.

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Bacteria• Eubacteria –• True bacteria• Ex: streptococcusWhich causes strep throat.

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Bacteria• Archaebacteria- • Archae means ancient• Most are anaerobic, (live in

environments with no oxygen).

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•Heterotrophs.

• Nearly all are motile.

• Animal cells do nothave cell walls.

Animals: Multicellular consumers

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Animals• Invertebrates & Vertebrates

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Protists• Plant like• Fungus like• Animal like• The kingdom into which things

are placed that can not be placed in any other kingdom.

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• Anal

• pore

A Paramecium

Kingdom Protista contains diverse species

that share some characteristics

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Fungi

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• Organisms in Kingdom Fungi are heterotrophs that do not move from place to place.

• A fungus is either a unicellular or multicellular eukaryote that absorbs nutrients from organic materials in the environment.

Fungi: Earth’s decomposers

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Fungi: Earth’s decomposers

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•Multicellular

•Photosynthetic eukaryotes that are stationary.

Plants: Multicellular oxygen producers

Cape Sundew

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What is the branch of biology that groups and

names organisms based on studies of their different

characteristics?

•Taxonomy

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Who developed binomial

nomenclature?•Linnaeus

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Name the 7 levels of taxa

• Kingdom• Phylum• Class• Order• Family• Genus• Species

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Name the 6 kingdoms.

•Plant•Animal•Eubacteria•Archaebacteria•Protist•Fungi

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Life’s Six Kingdoms

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More ClassificationLitter hurts Turtle survives!!

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Classification

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Phylogeny • Evolutionary history of a species.

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Cladistics

• Classification system that believes organisms evolved from a common ancestral group. As they evolve they retain some unique traits from that ancestor.

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Cladistics

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Crushing Bills

Probing Bills

Grasping Bills

Ancestral Species

Parrot Bills

SeedFeedersC

actu

s

Fee

ders

Insect

Feeders

Fruit

Feeders

Geographical distribution

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• These finches probably spread into different niches on the volcanic islands and evolved over time into many distinct species. The fact that they share a common ancestry is supported by their geographical distribution in addition to their genetic similarities.

Geographical distribution

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• For example, cauliflower, cabbage, kale, and broccoli look different but have chromosomes that are almost identical in structure.

Chromosome comparisons

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• Therefore, biologists propose that these plants are related.

Chromosome comparisons

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• Which of the following is NOT a way to determine evolutionary relationships?

D. geographical distribution

C. specific epithets

B. biochemistry

A. chromosome comparisons

The answer is C.

Question 1

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• How does a cladogram differ from a pedigree?

AnswerPedigrees show the direct ancestry of an organism from two parents. Cladograms show a probable evolution from an ancestral group.

Question 2

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• Using the cladogram, which of the following traits would be a primitive trait?

Theropods

Allosaurus

Sinornis

Velociraptor

Archaeopteryx

Robin

Light bones 3-toed foot; wishbone

Down feathers

Feathers withshaft, veins,and barbs

Flight feathers;arms as long

as legs

Question 3

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The answer is light bones. Primitive traits are traits that evolved very early.

Theropods

Allosaurus

Sinornis

Velociraptor

Archaeopteryx

Robin

Light bones 3-toed foot; wishbone

Down feathers

Feathers withshaft, veins,and barbs

Flight feathers;arms as long

as legs

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• Why do taxonomists use Latin names for classification?

Answer

Latin is no longer used in conversation and, therefore, does not change.

Question 4

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• What is the relationship between cladistics and taxonomy?

Answer

Cladistics is one kind of taxonomy that is based on phylogeny.

Question 5

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• Domain• Kingdo

m• Phylum

• Class

• Order

• Family

• Genus

• Species

• Eukarya

• Animalia

• Chordata

• Mammalia

• Carnivora

• Felidae

• Lynx

• Lynx • rufus

• Lynx • canadensis

• Bobcat• Lynx

Question 6

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Both organisms are members of the same kingdom, phylum, class, order, family, and genus but belong to different species.

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Which taxon contains the others?

D. family

C. genus

B. class

A. order

The answer is B.

Question 7

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Which of the following pairs of terms is NOT related?

D. Aristotle – evolutionary relationships

C. biology – taxonomy

B. binomial nomenclature – Linnaeus

A. specific epithet – genus

The answer is D.

Question 3

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What two main characteristics distinguish the members of the six kingdoms?

AnswerThe two characteristics are differences in cellular structures and methods of obtaining energy.

Question 5

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Which of the following is NOT true of both the animal and plant kingdoms?

D. cells contain cell walls C. cells are organized into tissues

B. tissues are organized into organs A. both contain organisms made up of cells

The answer is D.

Question 6

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Which of the following describes a fungus?

D. heterotrophic prokaryote

C. unicellular autotroph

B. unicellular or multicellular heterotroph

A. autotrophic prokaryote

Question 7

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The answer is B, unicellular or multicellular heterotroph.

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Why do some scientists believe that plants existed on Earth’s landmasses much earlier than fossils indicate?

Answer

Plants do not fossilize as often as organisms that contain hard structures, like bones, which more readily fossilize than soft tissues.

Question 10