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?

• Recognize similarities between living things (DNA, biomolecules, cells)

• Group organisms according to those similarities

• Taxonomy: the science of classifying organisms

• Who created Taxonomy?–Aristotle was the first scientist to group organisms based on physical characteristics –Carolus Linnaeus (1707 – 1778) a Swedish botanist , came up with the current system.

Classification Groups Classification Groups • The groups (largest to

smallest) – Domain– Kingdom– Phylum– Class– Order– Family– Genus – Species

• A sentence to help you remember! – Dear– King– Philip– Came – Over– For– Good– Soup

Levels of Classification: Levels of Classification: The 3 Domains The 3 Domains

(based on cell type)(based on cell type)

Eubacteria Eukaryota

Archaea

The Five Kingdoms The Three Domains

Levels of Classification: Levels of Classification: The 5 KingdomsThe 5 Kingdoms

- Based on…- Cell type- Number of Cells- Mode of Feeding Fungi

Animalia Plantae

Protista

Monera

The Five Kingdoms

Final 7 Levels of Classification Final 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 (animal cells, heterotroph)• PHYLUM: Chordata (all vertebrates)• CLASS: Mammalia (all mammals)• ORDER: Primata (all primates)• FAMILY: Hominidae (bipedal primates)• GENUS: Homo (humans and neanderthals)• SPECIES: Homo sapiens (humans only!)

Binomial NomenclatureBinomial Nomenclature• Binomial Nomenclature - the formal system of naming species. (Bi = two, nomial =

names)• The last two classification groups (genus and species) are used to create a unique

name for each species. – Because we use two groups for the name, similar species will have similar names. – Example: Ursus arctos (Grizzly Bear) and Ursus maritimus (Polar Bear)– In a species name, only the Genus is capitalized.

• Latin is the language used to make these names. Since it is no longer spoken anywhere, we do not have to worry about it changing.

What evidence is used to What evidence is used to classify?classify?

• Homologous (similar) Structures – Ex: The bones in a

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

• Similar Behaviors– Ex: All mammals

nurse their young

• Similarities in genes (DNA or protein sequence)– Ex: Human and

Primate DNA is 99% similar

Evidence for ClassificationEvidence for Classification

• Fossil Record: Past organisms studied through fossils– Ex: Trilobites and

horsehoe crabs

• Embryology: similar development patterns in unborn of different species– Ex: Dolphin limb buds

• Hybridization: ability to successfully interbreed different species.– Ex: Zorse

Homologous StructuresHomologous Structures

EmbryologyEmbryology

HybridizationHybridization