CLASSIFICATION

Who am I most closely related to????

WHAT IS CLASSIFICATION?

The word “classify” means to arrange or group

things based on shared characteristics or

qualities.

What are some things that are classified in

everyday life?

WHY DO WE CLASSIFY LIVING THINGS?

For order and organization:

There are close to 2 million known species on Earth.

The estimated number of species on Earth is

between 5 million and 30 million.

Classifying helps us understand the

evolutionary relationships among living things.

Classification improves communication

between scientists.

CLASSIFICATION VOCABULARY

Taxonomy – the science of naming and

classifying living things based on criteria, such

as appearance.

Systematics – the science of naming and

grouping organisms by their evolutionary

relationships.

Phylogeny – the study of evolutionary

relationships among organisms.

ARISTOTLE – EARLY CLASSIFICATION

Greek philosopher made the first groupings

Often referred to as the “Father of Biology”

2 main groups

Plants

Animals

ARISTOTLE’S PLANTS

Plants were grouped by

stem type.

Tree

Shrub

Herb

This was okay to a

degree because it was

based on structure.

ARISTOTLE’S ANIMALS

Animals were grouped by where they lived

Land

Water

Air

This was a problem because unrelated animals

were placed in the same group.

Ultimately, Aristotle’s system was inconsistent!

Is Closely Related To

?????

CAROLUS LINNAEUS – MODERN CLASSIFICATION

Swedish botanist who developed our current

naming system in the 1730’s.

Known as the “Father of Modern Taxonomy”

Binomial Nomenclature!

Two-part naming system

“bi” – two

“nomo” – name

BINOMIAL NOMENCLATURE

Each organism has a 2-part name, written in Latin, known as their scientific name.

Latin was used because it was the language of scholars at the time of Linnaeus. First part

Genus name

Always Capitalized

Second part Species name

Always lower case

Scientific names need to be underlined or italicized

Homo sapiens

Homo Sapiens

homo sapiens

Homo sapiens

SCIENTIFIC NAMES

Ursus martimus

GENUS: IDENTIFIES A GROUP

OF CLOSELY RELATED SPECIES

THE SECOND PART IS SPECIFIC TO THE

SPECIES AND OFTEN DESCRIBES THE

ORGANISMS HABITAT OR OTHER

IMPORTANT TRAIT

(martimus MEANS SEA)

QUESTION????

Which of these three are most similar/related?

Mentha rotundifolia

Bacopa rotundifolia

Mentha alopecuroides

*rotundifolia just refers to round leaves

• unrelated species could both have

round leaves

• you need to look at the genus

COMMON VS SCIENTIFIC

Common names are used in everyday

conversation about organisms.

There can be many common names, but only

one scientific name!

What is this?

Puma concolor

Note: concolor means “with one color”

MAJOR GROUPS

Devised by Linnaeus, but have since been modified.

Linnaeus arranged groups by structural similarities.

Now we look at genetic (biochemical) similarities as well.

MAJOR GROUPS

Eight Levels - Largest to Smallest Each level is called a taxon (plural – taxa)

Domain

Kingdom

Phylum

Class

Order

Family

Genus

Species

Dirty Kings Play Cards On Fat Green Stools

MAJOR GROUP INFO…

“Domain” is the most general

“Species” is the most specific, but needs to be used with the genus part of their name to have any real meaning.

A “species” of organism is identified by its full scientific name (genus and species).

Species: organisms that reproduce in nature and produce fertile offspring by mating with another of the same species.

Horse + Donkey = Mule (infertile) so horses and donkeys can NOT belong to the same species

RELATIONSHIPS WITHIN GROUPS

Organisms in the same group share certain characteristics.

The more specific the group, the more the organisms in that group will have in common.

Phylum Chordata

RELATIONSHIPS WITHIN GROUPS

Class Aves

Order Passeriformes