Classification

In order to make their job easier, scientists classify living things into groups, based on how they are the same, and how they are different.

What is Classification?

Classification arranges objects, ideas, or information

into groups by finding common

traits or characteristics.

The Science of Classification

Scientist who classify ororganize organisms (animals and plants)

are called taxonomists.

Taxonomists study taxonomy.

The History of Organization

Aristotle 384-322 BCInterested in biological classification.

Patterns in nature.

Carl Linnaeus1707-1778 ACE

Father ofBiological

Classification!

Binomial Nomenclature

Two-word naming system– Genus

• Noun, Capitalized, Underlined or Italicized

– Specific epithet• Descriptive, Lower Case,

Underlined or Italicized

– Together they are the species name.

• Without the genus name, the specific epithet is meaningless

Common name: Robin

• Erithacus rubicula

• Turdus migratorus

Common name: Black and Polar Bear

Ursus americanus

Ursus maritimus

Why not use common names?

• Scientists avoid using common names because they are often not specific to a particular species and can be confusing.

• Different countries (and different regions within countries) have different common names for the same organisms

• Common names such as blue crab, redfish, and dolphin are successfully used in casual communication, and convey an immediate idea of what a particular animal or plant looks like.

Groups are also arranged in hierarchical order.

Hierarchical Classification

• Taxonomic categories– Domain (big) Dear– Kingdom King– Phylum Philip– Class Came– Order Over– Family For– Genus Good– Species (small) Soup

What are Dichotomous Keys?

• a method for determining the identity of something (like the name of a butterfly, a plant, a lichen, or a rock) by going through a series of choices that leads the user to the correct name of the item.

• Dichotomous means "divided in two parts".

Using a dichotomous keyAt each step of the process of using the key, the user is

given two choices; each alternative leads to another question until the item is identified.

1a. If the leaves are flat….go to question 4. 1b. If the leaves are needle-like….go to question 2.2a. Are the needles in a bunch? Go to question 52b. Are they spread along the branch?“…pine tree

Eventually, when enough questions have been answered, the identity of the tree is revealed.

Quiz tomorrow!!!!!!!

1. Start by observing the group of things to be used in the key.

2. List the most general traits that can be used to divide the organisms into categories.

3. create a series of numbered steps with the first step showing the first characteristic you used. At each step, offer two choices for classifying the beetle based on a single characteristic.

4. There should be one less step than the total number of organism to be identified in your dichotomous key.