1. Classification of Living Things

2. Taxonomy: The branch of biology that names and groups organisms according to their characteristics.
(Does it have a backbone? Feathers? Gills? Flippers?
Evolutionary History: Shows how an organism changed through the fossil record. What other organisms is it related to?

3. The first person to group or classify organisms was the Greek teacher and philosopher Aristotle more than 2000 years ago.
(300 B.C.)

4. Aristotle’s system Plants: Based on size of stem. Animals: Based on
where they lived.

5. Problems?
1. Not all organisms fit into Aristotle’s 2 groups (plants or animals)
Ex: Bacteria Fungi

6. 2. Common names can be misleading.
Problems?
2. Common names can be misleading.
Ex: A jelly fish isn’t a fish, but a seahorse is!
Sea Cucumber sounds like a plant, but it’s an animal.

7. Problems? 3. Common names vary from place to place.
Puma, mountain lion, cougar…
4. Different organisms have different names in different countries.

8. Solution?
Some early scientists devised scientific names using long descriptions in LATIN.
RED OAK
Quercus foliis obtuse-sinuatis setaceo-mucronatis

9. Carolus Linnaeus: Devised a new classification system based on Morphology. (Organism’s form and structure)
( )

10. Grouped organisms into 7 different levels.
Linnaeus’s System:
Grouped organisms into 7 different levels.
Each organism has a two part Latin Scientific Name.
Kingdom
Phylum
Class
Order
Family
Genus
Species

12. Kingdom Animalia
Phylum Chordata
Class Mammalia
Order Carnivora
Family Felidae
Genus Panthera
Species leo

13. Binomial Nomenclature
(2 name naming system)
• 1st name= Genus
• 2nd name= Species
Vampire bat Desmodus rotundus

14. Modern Taxonomy

15. Modern Taxonomy
Organizes living things in the context of Evolution.

16. Modern Taxonomy
Scientists use different kinds of info to classify organisms:
_Fossil record________
_Morphology_________
_Embryology_________
_Chromosomes______
_Macromolecules (DNA and Proteins)

17. Evolutionary history = _____________
1. Fossil Record
We can trace some changes over time through the fossil record.
Evolutionary history = _____________
PHYLOGENY

18. 2. Morphology Shape and Function

19. Morphology Homologous characteristics: :same embryological origin.
:may have similar structure and
function.
Ex:bat wing and human arm.
Homologous characteristics suggest a recent common ancestor.

20. Homologous Structures
Bat wing
and human arm
develop from same embryonic structures

21. 3. Embryology
Animals whose embryos develop in a similar pattern may be related