1. TOPIC: Classification AIM: What is classification?

2. Thousands of years ago, people started to realize that there were many different groups of living things. There were many different types of plants and animals. They started organizing them into groups based on certain characteristics. This is called CLASSIFICATION.

3. Less than 2 million have been classified so far!
Scientists have identified more than 5-50 million different organisms. And their job isn’t even close to being finished! Some biologists estimate that there may be at least 7 million different kinds of organisms living in tropical rain forests and in the depths of Earth’s oceans. No wonder why we need to classify!
Less than 2 million have been classified so far!

4. Grouping of organisms based on similarities in structure
What is
classification?
Grouping of organisms based on similarities in structure

5. Branch of biology that deals with classification
What is
taxonomy?
Branch of biology that deals with classification

6. The First Classification Systems
Greek philosopher Aristotle, in 4th century BC, divided living things in 2 groups: Plants and Animals. He also placed animals into 3 groups according to how they moved (ones that flew, swam, walked). Birds and bats were placed into the same group even though they are quite different. This system was used for almost 2000 years. Around the 17th century scientists started to classify organisms in a more meaningful way (form and structure).

7. Today’s classification system is based on the work of Swedish scientist Carolus Linnaeus. He classified living things as plants or animals but grouped them according to similarities in form and structure. He used a system that consisted of groups within larger groups within larger groups.

8. All organisms are divided into 7 levels of classification
What
classification
system do we
use?
Carolus Linnaeus (1700’s)
All organisms are divided into 7 levels of classification

9. Phylum Class Order Family Genus Species Largest groups
Kingdom
Phylum
Class
Order
Family
Genus
Species
Largest groups
Smallest groups and most closely related to each other

11. Kings
Play
Chess On
Fine
Green
Stools

12. 5 kingdoms
Largest classification group
Very diverse
Kingdom

15. Species One kind of organism Most specific way to classify an organism
Can produce fertile offspring with each other
Species

16. Kingdom
Phylum
Phylum
Phylum
Phylum
Phylum
Phylum

18. Naming organisms
Before Linnaeus developed his naming system, plants and animals were named by a series of Latin words that described the physical appearance of the organism. This was very confusing. For example, let’s look at the first name of the honey bee.
Apis pubescens, thorace subgriseo, abdomine fusco, pedibus posticis glabris utrinque margine ciliatus.
This means “fuzzy bee, light gray middle, brown body, smooth hind legs that have a small bag edged with tiny hairs.” Linnaeus named it Apis mellifera which means “honey-bearing bee.”

19. Binomial Nomenclature Two-word system of identifying organisms
Carolus Linnaeus
Binomial Nomenclature
Two-word system of identifying organisms
How do we
name
organisms?

20. Genus & species Examples: Humans Homo sapiens Homo = Genus
sapiens = species

22. Humans = Homo sapiens Kingdom Animalia Phylum Chordata Class Mammal
Order
Primate
Family
Homoide
Genus
Homo
Species
sapiens

23. Canis lupus Kingdom Animalia Phylum Cordata Class Mammalia Order
Carnivora
Family
Canidae
Genus
Canis
Species
Lupus (the wolf)
Canis lupus

24. Dolphin  Tursiops truncatus

25. Raccoon  Procyon lotor

26. Fruit flyDrosophila melanogaster

30. List of characteristics used to identify an organism
Dichotomous
Key
List of characteristics used to identify an organism
Arranged in steps (2 statements at each step)
Workbook: page