1. Classification of Living Things

2. What is Classification?
The arranging of organisms into groups according to how they are alike = classification.
Taxonomy = The branch of Biology that involves identifying, classifying, and naming organisms.
Scientists who study Taxonomy are Taxonomists.

3. Early Classification
Aristotle, a Greek philosopher, developed the first widely accepted system of classification.
Classified organisms into two main groups and further broke them down by observable traits:
Plants
Herbs
Shrubs
Trees
Animals
Swam
Flew
Walked

4. Aristotle's Animal Classification System
Question:
Which animas have no red blood, soft bodies and a shell?
Does this system work for all organisms on the planet?
Shellfish
Not even close!

5. A New Approach Aristotle’s system lasted for centuries.
But as new organisms were discovered the system wasn’t allowing for their classification.
Carolus Linnaeus, 18th century, developed a new method of classification.
based on the physical and structural similarities.
His system of classifying and naming organisms survives to this day.
Movie: Carl Linnaeus 3:58 min

6. Basis for Classification
Modern classification is based on the idea that organisms who share a common ancestor are related and also share a similar evolutionary history.
Evidence:
Structural Similarities
Evolutionary Relationships
Genetic Similarities

7. Structural Similarities
If two organisms have similar structures, they likely evolved from a common ancestor.
Who is the most structurally similar to each other?
Domestic Dog & Wolf
Who is the least structurally similar to each other?
Cat to the Domestic Dog & Wolf

8. Evolutionary Similarities
The more recent two organisms split from a common ancestor the closer related they are.
Which two organisms have
the closest ancestor?
What level of classification
do ONLY these two share?
Which organisms have the
most distant ancestor?
do they share?
Domestic dog & wolf
Genus - Canis
Cat to Dog & Wolf
Order - Carnivora

9. Genetic Similarities
Chromosomes (X)– The number and structure of chromosomes also indicate a common ancestor. 38 64 60 78 78

10. Levels of Classification
Classification is based on groups of organisms that all have similar characteristics but can be broken down to the individual by a specific characteristics within that group. – hierarchial system.
(Largest most general grouping)
Your LAST NAME, FIRST NAME
(smallest and most specific)

11. 5 Kingdoms
Monera – primitive cell structure lacking a nuclear membrane.
Ex. Bacteria & Blue-green Algae
Protista – Has membrane bound organelles but unicellular.
Ex. Protozoa & Algae
Fungi – Has membrane bound organelles but doesn’t ingest food, instead absorbs nutrients.
Ex. Molds, mushrooms & Yeast
Plant – photosynthetic multicellular organisms.
Ex. Plants
Animal – Multicellular and ingests their food
Ex. Animals

12. Domains All life falls within three Domains, the highest level of
organization.

13. Understanding Levels
The Sea Star, Abert Squirrel and Giant Panda all share this level.
Ursidae is this level of classification?
What level does the Grizzly occupy all by itself?
Kingdom Anamilia
Family
Species – Ursus arctos

14. Naming Organisms
Common names differ depending on where you happen to be:
Florida panther = puma, cougar, mountain lion or panther.
Linnaeus used a two-part (Genus and Species) Greek or Latin name to create unique individual names for each organism – Binomial Nomenclature
Binomial = “two names”
Nomenclature = “naming”

15. Naming Organisms Florida Panther = Felis Concolor
Always written in itallics
Felis = genus
always capitalized!
concolor = species
always lower case!

16. Dichotomous Key Dichotomous = “two parts”
Dichotomous Keys are made up of several pairs of opposing statements based on observable characteristics.
Choose the statement that best describes the organism and move on to the next set of statements.
When you can’t move any further through a pairing you should be at the name of the organism you’re identifying.

17. Dichotomous Key
Eagle
Jacana
Cormorant
Kingfisher