Transcript leopard - Ms. Coonley

Lecture 1: Classification
OBJECTIVES:
•Explain Phylogeny and describe the
information presented in a Phylogenic Tree
•Create a Cladogram
•Explain data used to create Phylogenies
What does the Linnaean System of
Classification
use
to
Classify
Organisms?
Physical Traits
Are these two
organisms closely related?
Is this sufficient?
What are the levels of Linnaean
classification
Domains
• Archaea
– Prokaryotic
– Have unique ancient evolutionary history
– Often live in extreme environments
• Bacteria
– Prokaryotic
• Eukarya
– Eukaryotes
Kingdoms
• Six Kingdoms
– Domain Archaea
• Kingdom Archaea
– Domain Bacteria
• Kingdom Bacteria
– Domain Eukarya
•
•
•
•
Kingdom Animalia
Kingdom Fungi
Kingdom Plantae
Kingdom Protista
Phylogeny
• Evolutionary history of a species
• Branching tree diagrams
• To reconstruct phylogeny, scientists
use cladistics
Species
Mephitis
mephitis
(striped skunk)
Lutra lutra
(European
otter)
Genus
Panthera
Mephitis
Lutra
Family
Felidae
Order
Panthera
pardus
(leopard)
Mustelidae
Carnivora
Canis
familiaris
(domestic dog)
Canis
Canidae
Canis
lupus
(wolf)
Leopard
Domestic cat
Each branch point represents the divergence of two species
Common ancestor
Wolf
Leopard
Domestic cat
“Deeper” branch points represent progressively
greater amounts of divergence
Common ancestor
Millions of
years ago
Neoproterozoic
542
Paleozoic
251
Mesozoic
65.5
Cenozoic
What is Cladistics
• Classification based on shared
ancestry
• Cladogram
– Branching trees: closer the branches=
more closely related
– Clade
• Group of species that share a common
ancestor
What is a Cladogram
• Depicts patterns of shared derived
characteristics among taxa
– Synapomorphies
• The more synapomorphies two species share,
the more closely related they are
• The chronological sequence of
branching during the evolutionary
history of a set of organisms
How are Cladograms constructed?
Morphological similarities
Homologous structures
Structures from a common ancestor
Molecular Similarities
Molecular Homologies
DNA
Organisms with very similar morphologies or DNA sequences
are likely to be more closely related than organisms with
vastly different structures or sequences