1. Classification
Chapter 17

2. The science of naming and classifying organisms
Taxonomy
The science of naming and classifying organisms

3. Early Ideas… Aristotle: Classified all living things into 2 groups:
Plants or Animals
(trees, shrubs, herbs) (Air, Water, Land)

4. 1700’s – ***Linnaeus*** developed Binomial nomenclature: a two-word system for naming organisms
Universal - Latin & consists of genus (first word) and species (second word)
Examples: Homo sapiens – humans
Quercus rubra – red oak
Quercus alba- white oak
Panthera leo – lion
Panthera tigris – tiger
1. Always capitalize the genus and lowercase the species.
2. Always italicize or underline both words!

5. King Phillip Came Over For Good Spaghetti
All organisms are classified into a 7 group, hierarchal system:
Kingdom contains…
Phylum contains…
Class contains…
Order contains…
Family contains…
Genus contains…
Species

6. Kingdom
Phylum
Class
Order
Family
Genus
Species

7. Can you guess the organism?
Gorilla gorilla
Rosa odoratus
Felis domesticus
Canis familiaris
Trichecus manatus
Rhinoceros unicornis
Camelus dromedarius
Ursus maritumus
Ursus horribilis

8. Dichotomous key for Leaves
A key used to help identify species
Dichotomous key for Leaves
Compound or simple leaf
1. Compound leaf (leaf divided into leaflets)…………………….……………………….…………………………..…. go to step 2
Simple Leaf (leaf not divided into leaflets)….………………………………………………………………………….go to step 4
Arrangement of leaflets
2. Palmate arrangement of leaflets (leaflets all attached at one central point)…………………………….Aesculus (Buckeye)
Pinnate arrangement of leaflets (leaflets attached at several points)……………………………………………….go to step 3
Leaflet shape
3. Leaflets taper to pointed tips………………………………………………………………………………….……..Carya (Pecan)
Oval leaflets with rounded tips …..…………………………………………………………………………....….Robinia (Locus)
Arrangement of leaf veins
4. Veins branch out from one central point……………………………………………………………………….…..….go to step 5
Veins branch off main vein in the middle of the leaf…………………………………….……………………….…..go to step 6
Overall shape of leaf
5. Leaf is heart shaped…………..……………………………………………………………………………………Ceris (Redbud)
Leaf is star shaped……………………………………………………………………………………Liquidambar (Sweet gum)
Appearance of leaf edge
6. Leaf has toothed (jagged) edge…………………………………………………………………………..……..….Betula (Birch)
Leaf has untoothed (smooth) edge……………………………………………………………………....…Magnolia (Magnolia)

9. Buckeye
Birch
Pecan
Sweet Gum
Redbud
Magnolia
Locus

10. Taxonomy Reveals Evolutionary History
Evolutionary history = PHYLOGENY
Biologists reconstruct phylogenies through CLADISTICS – used to determine the sequence of when organisms may have evolved – based on similarities (molecular, structural, behavioral, geographical, etc.)

11. What is a Cladogram?
A branching diagram showing the relationship between a number of species

12. Constructing a Cladogram
What is a Cladogram: