17.2 classification based on evolutionary relationships 13.1 ecologists study relationships titd:...
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17.2 Classification Based on Evolutionary Relationships13.1 Ecologists Study Relationships
On your “What is Cladistics?” paper make sure you have answered all 8 questions and used CUBS on all paragraphs. We will be going over your answers in 10 minutes.
C ircle – will be done as a classU nderline – important facts and informationB ox – vocabulary S tar – questions
TITD: 1/26 and 1/27
17.2 Classification Based on Evolutionary Relationships
1. What is CLADISTICS?
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17.2 Classification Based on Evolutionary Relationships
2. Differentiate between primitive and derived characteristics
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17.2 Classification Based on Evolutionary Relationships
3. Define the following terms;plesiomorphicsymplesimorphicapomorphicautapomorphicsynapomorphicsister group (clade)
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17.2 Classification Based on Evolutionary Relationships
4. What does a note represent?
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17.2 Classification Based on Evolutionary Relationships
5. Explain the difference between monophyletic, paraphyletic, and poyphyletic groupings.
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17.2 Classification Based on Evolutionary Relationships
• 6. Why are reptiles a paraphyletic group?
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17.2 Classification Based on Evolutionary Relationships
7. Why does convergent evolution complicate cladistics analysis?
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17.2 Classification Based on Evolutionary Relationships
8. What is the principle of parsimony?
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17.2 Classification Based on Evolutionary Relationships
You have 2 minutes to collect your notebook from the front of the class
room.
Chapter 17. 2 NOTES
17.2 Classification Based on Evolutionary Relationships
KEY CONCEPT Modern classification is based on evolutionary relationships.
17.2 Classification Based on Evolutionary Relationships
Cladistics is classification based on common ancestry.
• Phylogeny is the evolutionary history for a group of species.
• evidence from living species, fossil record, and molecular data
• shown with branching tree diagrams
17.2 Classification Based on Evolutionary Relationships
• Cladistics is a common method to make evolutionary trees.
– classification based on common ancestry– species placed in order that they descended from
common ancestor
17.2 Classification Based on Evolutionary Relationships
• A cladogram is an evolutionary tree made using cladistics.
– A clade is a group of species that shares a common ancestor.
– Each species in a clade shares some traits with the ancestor.
– Each species in a clade has traits that have changed.
17.2 Classification Based on Evolutionary Relationships
• Derived characters are traits shared in different degrees by clade members.
– basis of arranging species in cladogram
– more closely related species share more derived characters
– represented on cladogram as hash marks FOUR LIMBS WITH DIGITS
Tetrapoda clade1
Amniota clade2
Reptilia clade3Diapsida clade4
Archosauria clade5
EMBRYO PROTECTED BY AMNIOTIC FLUID
OPENING IN THE SIDE OF THE SKULL
SKULL OPENINGS IN FRONT OF THE EYE & IN THE JAW
FEATHERS & TOOTHLESS BEAKS.
SKULL OPENINGS BEHIND THE EYE
DERIVED CHARACTER
17.2 Classification Based on Evolutionary Relationships
FOUR LIMBS WITH DIGITS
• Nodes represent the most recent common ancestor of a clade.
• Clades can be identified by snipping a branch under a node.
Tetrapoda clade1
Amniota clade2
Reptilia clade3Diapsida clade4
Archosauria clade5
EMBRYO PROTECTED BY AMNIOTIC FLUID
OPENING IN THE SIDE OF THE SKULL
SKULL OPENINGS IN FRONT OF THE EYE AND IN THE JAW
FEATHERS AND TOOTHLESS BEAKS.
SKULL OPENINGS BEHIND THE EYE
NODE
DERIVED CHARACTER
CLADE
17.2 Classification Based on Evolutionary Relationships
Molecular evidence reveals species’ relatedness.
• Molecular data may confirm classification based on physical similarities.
• Molecular data may lead scientists to propose a new classification.
• DNA is usually given the last word by scientists.
17.2 Classification Based on Evolutionary Relationships
Get out a sheet of notebook paper
Title is CLADISTICS PRACTICE
Do NOT forget your Name, the date, and class period
PRACTICE
17.2 Classification Based on Evolutionary Relationships
CHARACTERS
TAXA
Lancelet
Lamprey
Tuna
Salamander
Turtle
Leopard
Hair
Amniotic (shelled)
egg
Four Walking
legs
Hinged jaws
Vertebral column
(backbone)
PRACTICE
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Lancelet
17.2 Classification Based on Evolutionary Relationships
Lamprey Shark Salamander
Lizard Tiger Gorilla Human
Bipedal
No tail
Hair
Amniotic membrane
Lungs
Jaws
YOUR TURN
Using the character traits and animals below create your data chart, Venn diagram and Cladogram on the back of your practice paper due at the end of class.