Biological Biological ClassificationClassification

Group the following in any way Group the following in any way you would like, you would like,

but justify your grouping! but justify your grouping!

• Frogs• Bears• Ants• Spiders• Bacteria

• Humans• Dolphins• Sharks• Mushrooms• Pine Trees

Why do we Classify?Why do we Classify?

• To group organisms according to similarities

•  Taxonomy is the science of classifying organisms. 

Binomial NomenclatureBinomial Nomenclature

• Binomial Nomenclature - the formal system of naming species. (Bi = two, nomial = names)– Latin is the language in which scientific names are written.

• Carolus Linnaeus (1707 – 1778) a Swedish botanist , came up with the b.n. system.

• Aristotle was the first scientist to group organisms based on physical characteristics.

The 3 DomainsThe 3 Domains

Eubacteria Eukaryota

Archaea

The Five Kingdoms

The Three Domains

The 5 KingdomsThe 5 Kingdoms

Fungi

Animalia Plantae

Protista

Monera

The Five Kingdoms

Fungi

Animalia Plantae

Protista

Monera

The Five Kingdoms

7 Levels of Classification 7 Levels of Classification 1 is Largest- 7 is Smallest1 is Largest- 7 is Smallest

7. Species

6. Genus

5. Family 4. Order

3. Class

2.Phylum

1. Kingdom

7 Levels of 7 Levels of ClassificationClassification

Examples of ClassificationExamples of Classification

Common Pond Amoeba• KINGDOM: Protista • PHYLUM: Sarcomastigophora • CLASS: Sarcodina • ORDER: Granulopodea • FAMILY: Amoebidae• GENUS: Amoeba • SPECIES: Amoeba proteus

Examples of ClassificationExamples of Classification

Humans• KINGDOM: Animalia • PHYLUM: Chordata• CLASS: Mammalia • ORDER: Primata • FAMILY: Hominidae • GENUS: Homo • SPECIES: Homo sapiens

Scientific NamesScientific Names

• The GENUS is the 1st word in the scientific name. Always capitalized

Example : Amoeba proteus

Homo sapiens

• The SPECIES is the 2nd word in the scientific name. Always lowercase

Example: Amoeba proteus

Homo sapiens

Phylogenetic TreePhylogenetic Tree• A Phylogenetic Tree is a way to organize living things

and show how they are related.

CladogramsCladograms

• Cladograms are a way to show shared or lost traits between related organisms

How do we know how to How do we know how to classify?classify?

• Similar Structures – The bones in a

bat’s wing are almost the same as the bones in a human hand

• Similar Behaviors– All mammals nurse

their young

• Similarities in genes (DNA sequence or proteins)– Human and

Primate DNA is 99% similar

Evidence for Evidence for Classification/EvolutionClassification/Evolution

• Homologous structures: similar bone structures in different organisms

• Fossil Record: Past organisms can be studied through fossils

• Gene similarities: matching DNA sequences

• Embryology: similar development patterns in unborn species of different species

• Hybridization: ability to successfully interbreed different species.

Homologous StructuresHomologous Structures

EmbryologyEmbryology

HybridizationHybridization