Scientific Classification and Taxonomy

SB 3 c.Examine the evolutionary basis of modern

classification systems

CLASSIFICATION the grouping of organisms by

similarities Biological classifications are

based on how organisms are related.

Group A Group B

HISTORY: Aristotle- developed the 1st

method of classification

He divided all living things into 2 major groups

Aristotle (384 - 322BC)

Aristotle’s Groups He divided all living things into 2

major groups 1. Plants

classified by size and structure

2. Animals classified by habitat (where they

lived)

HISTORY: Aristotle Problems with his system:

Frogs live in both water and on land

HISTORY: Aristotle Problems with his system:

Bats, birds and flying insects were grouped together

HISTORY: Carolus

Linnaeus- developed the modern system of classification

Father of Taxonomy

Taxonomy the branch of biology

concerned with the grouping and naming of organisms; the study of classification

MODERN CLASSIFICATION SYSTEM Organisms are grouped

together on the basis of: Similarity in structure

( anatomy)

Felis domesticus

Felis rufusPanthera leo

Similarity in structure

Canis lupus

Organisms are grouped together on the basis of:

Similarity in genetic makeup (biochemistry)

Organisms are grouped together on the basis of:

Similarity of embryonic development

Organisms are grouped together on the basis of:

Similarity in behavior

Organisms are grouped together on the basis of:

Similarity in evolutionary history

Phylogeny: the evolutionary

history of a species based on comparing relationships between species using the fossil record

Classification is based on close evolutionary relationships of organisms.

Organisms classified in the same taxa (pl.) (taxon, sing.) share a common ancestry. They have evolved from the same common ancestral organism.

Classification is hierarchal

each successive level is smaller and more closely related than the one before it

Domain – Largest Group Kingdom Phylum (sing.)

Phyla (pl.)(Plants don’t have phyla, they have divisions.)

Class Order Family Genus Species – smallest taxon

These two taxa make up the scientific name.

D__________ k __________ p__________ c_________ o___________ f________ g_________ s________.

Dominating kings play chess on fine gold sets.

D_________K__________ p__________ c_________

o___________ f________ g_________ s________.

Dear King Phillip came over for great soup.

Binomial Nomenclature

Binomial nomenclature is a standard way of identifying a species with a scientific two-word name.

The first word is the genus name and the second the species name.

Binomial Nomenclature Scientific name - 2 Latin names - Genus and species - Capitalize the first letter of the

genus - Do NOT capitalize the species - ALWAYS underline or use

italicsEx. Homo sapiens

Binomial Nomenclature

Scientific Name: Homo sapiens

Common Name: Daddy & Olivia

Binomial Nomenclature

Scientific Name: Rudbeckia hirta

Common Name: Gloriosa daisy

or Black-eyed Susan

Binomial Nomenclature

Scientific Name: Pinus virginianis

Common Name: Virginia Pine

Binomial Nomenclature

Scientific Name: Harmonia axyridis Common Name: Asian Ladybug

Binomial Nomenclature

Scientific Name: Ophiophagus hannahCommon Name: King Cobra

Why use scientific names? Common names do not indicate how

organisms are related or classified.

Common names can be misleading. (e.g., seahorse, weeping willow)

Organisms with more than one common name leads to mass confusion.

Why Latin? Latin is no longer spoken, and

therefore, does not change as spoken languages do.

So, scientific names remain the same forever.