Classification
& the New
Taxonomy
2010-2011
Chapters
25 – 35
New songs!
• https://www.youtube.com/watch?v=dnF_UdP
bJZ0
• https://www.youtube.com/watch?v=gj15UF08
lUI
What determines life?
• There are 6 characteristics of life:
– Organization
– Metabolism
– Homeostasis
– Growth and Development
– Reproduction
– Adaptations
Solar System
Finding commonality in variety
• Organisms classified
from most general
group, domain, down
to most specific,
species
– domain, kingdom,
phylum, class, order,
family, genus, species
Earth
No. America
U. S.
N. Y.
L. I.
Nassau Co.
use the mnemonic!
Levittown
Eukaryote
Classification
• Old 5 Kingdom system
Prokaryote
• Monera, Protists, Plants, Fungi,
Animals
• New 3 Domain system
– reflects a greater understanding
of evolution & molecular
evidence
• Prokaryote: Bacteria
• Prokaryote: Archaebacteria
• Eukaryotes
– Protists
– Plants
– Fungi
– Animals
Archaebacteria
&
Bacteria
Kingdom
Bacteria
Kingdom
Archaebacteria
Kingdom
Protist
Kingdom
Fungi
Kingdom
Plant
Kingdom
Animal
Binomial Nomenclature
• Was established in the 18th century by Carlus
Linnaeus
• Based on structural features as opposed to
habitat, size etc.
• He used genus which acted as a noun telling
what it was
• He also used species name which was an
adjective to describe the genus
Taxon
• Term used for the hierarchical classification
groups
• The smaller the taxon the more similar the
organisms within it
The Evolutionary Perspective
Kingdoms
Fungi
absorptive
nutrition
Animalia
ingestive
nutrition
Plantae
autotrophs
Protista
uni- to
multicellular
Eubacteria
multicellular
Archaebacteria
prokaryotes
Single-celled ancestor
eukaryotes
heterotrophs
Bozeman
• https://www.youtube.com/watch?v=wGVgIcT
pZkk
Why are common names bad?
• The classification system makes it easier and quicker to
locate different species
• There is a uniform Latin language used so it doesn’t
have to be translated between languages. It makes it
easier for scientists of the world to share information.
• It avoids the confusion of common names. For example
Ragwort is 2 different plants on PEI and outwest (PEI’s
is poisonous)
• Puma, Mountain Lion, and Cougar are all the same
animals but named different things in different
countries
Dichotomous Keys
• Dichotomous means divided into two parts
therefore these keys always give 2 choices in
each step.
• Sheet
Evidences for Classification
1. Fossil Record: radiocarbon dating
Evolution of birds
• Archaeopteryx
– lived about 150 mya
– links reptiles & birds
Smithsonian Museum,
Washington, DC
2006 Fossil Discovery of Early Tetrapod
• Tiktaalik
– “missing link” from sea to land animals
2. Anatomical record
• Homologous structures
– similarities in characteristics resulting from
common ancestry
Homologous structures
•
•
•
•
Similar structure
Similar development
Different functions
Evidence of close
evolutionary relationship
– recent common ancestor
3. Comparative embryology
• Similar embryological development in closely
related species
– all vertebrate embryos have similar structures at
different stages of development
• gill pouch in fish, frog, snake, birds, human, etc.
4. Molecular record
• Comparing DNA & Biochemistry (blood,
protein, hormones)
– universal genetic code!
Why compare
these genes?
• DNA & RNA
– compare common genes
• cytochrome C (respiration)
• hemoglobin (gas exchange)
Human/kangaroo
100
 DNA & proteins are a molecular record of
evolutionary relationships
75
Nucleotide substitutions
Closely related species have sequences that are
more similar than distantly related species
Dog/
cow
Human/
cow
Rabbit/
rodent
Llama/
cow
Horse/
donkey
50
Horse/cow
Sheep/
goat
25
Human/rodent
Pig/
cow
Goat/cow
0
0
25
50
75
Millions of years ago
100
125
5. Behaviour
• Song Bird: birds that have the same song
would be classified more closely
6. Cell Structures
• Peptidoglycan = bacteria in cell wall
Phylogeny
• Evolutionary history of an organism
• We often use cladograms to show this history
and relationship to other living things
• Like a tree the organisms at the top are the
most recent
Comparative hemoglobin structure
Human
Macaque
Dog Bird
Frog
32 45
67
Lamprey
Why does comparing
amino acid sequence
measure evolutionary
relationships?
8
125
0 10 20 30 40 50 60 70 80 90 100 110 120
Number of amino acid differences between
hemoglobin (146 aa) of vertebrate species and that of humans
Book Examples
• Pg. 115 Horseshoe crab reclassified
• Interesting chart on pg. 119