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Chapter 9 Key Terms

Taxonomy Domain

Binomial Nomenclature Speciation

Migration Adaptation

Baraminology Derived Character

Phylogenetic Tree Geographic Isolation

Behavioral Isolation Biological Species

Artificial Classification System

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Biology Chapter 9CLASSIFICATION OF ORGANISMS

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Why Classify?

TaxonomyThe science of classifying organisms into groups

We classify organisms by putting them into groups with similar properties

Grouping them helps organize information about these organisms

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Classification

Aristotle was the first to attempt classifying organisms 2 major groups: animals and plants Plants were divided into trees, shrubs, herbs Animals were divided into fish, birds, animals

Artificial Classification System System for classifying organisms based on observable

characteristics

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Classification

Carolus Linnaeus Proposed new system for classifying organisms More flexible than Aristotle’s

As new species are discovered, scientists propose revisions to this system

Today’s system is a classification hierarchy

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Classification

1. Each group on one level may be divided into several groups on the next layer

2. Each group in the hierarchy has various characteristics that all levels under the group possess

3. Each level of the hierarchy can be divided into smaller units before reaching the next lower level

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Kingdoms

Kingdom EubacteriaMost abundant organisms on the earthUnicellular prokaryotic organismsContain peptidoglycan

Kingdom ArchaebacteriaAlso prokaryotic organismsDo not contain peptidoglycanMany are considered extremophiles

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Kingdoms

Kingdom ProtistaProtists are eukaryotic organisms that are not animals,

plants, or fungusAlgae, protozoans, slime molds

Kingdom FungiHeterotrophic and feed on dead or decaying organic

matterMushrooms, yeasts, mildews, molds

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Kingdoms

Kingdom PlantaeMost are autotrophic and perform photosynthesisAdults are usually stationaryCells surrounded by cell walls

Kingdom AnimaliaHeterotrophic, eukaryotic, multicellular organismsContain some means of locomotion Insects, fish, worms, birds, mammals…

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Scientific Names

A naming system had to be derived because different organisms can have the same name, and one organism can have several names

Binomial NomenclatureProposed by Carolus Linnaeus2 name, naming systemEach organism is given a genus and species name

specific to that organismUses Latin for names

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Scientific Names

The scientific name for an organism uses the genus and species names

Name is always italicized if printed, underlined if hand written

Genus name is capitalized, species name is not Ex. the genus for horse is Equus Equus caballus is the common name for the common

horse

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Species

“A group of similar organisms” Members of a species are structurally similar but do have a

degree of variation Members of a species can interbreed and produce viable and

fertile offspring under natural conditions Biological species

A group of individuals that resemble each other and can generally interbreed to produce fertile, viable offspring

Still does not give a complete definition for every species

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Species

Speciation Formation of new species Does not create new information

Migration Moving of organisms from one area to another

Geographic Isolation Inability of organisms to breed due to physical separation

Behavioral Isolation Inability of organisms to reproduce due to conflicting

reproductive behaviors

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Kinds

Biblical Kind Organisms that are able to reproduce Linnaeus thought he was using the same classification

when referring to a species

Baraminology Study of classification based on the idea of biblical kinds

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Evolution

Phylogenetic TreeEvolutionary diagrams that

show the evolutionary path of an organism

Scientists try to show that the similarities are a result of common ancestors