Bio 9C: Thursday, 5.5.11
Title: Using homologous structures as evidence for evolution
Double Block



Homework:
 Lab Part B: Finish Tree #1 and Analysis Question #6 by the
start of tomorrow’s class!
Do Now(s):
 Power-up a laptop and get ready for your next instructions
Today’s Objectives:
 Use the three different types of homologies as evidence for
evolution
EVIDENCE FOR
EVOLUTION
PHA Biology 9
Moretti/ Dickson
Evolution 3-Part Investigation Dry Lab
Key Questions:
1.
What is the evidence that one species
can branch into two?
2.
What is the evidence that multiple
species are evolutionarily related?
Objectives for Class:
• Use the three different types of homologies as evidence for evolutionary relationships
Evidence for Evolution
Dry Lab: Part A
Evolution Dry Lab Part A
Part A Computer Lab
All in the Family: Which Animals are the Closest Relatives?
Link: http://www.pbs.org/wgbh/evolution/change/family/index.html
The purpose of this series of lab activities is for you to…
Examine and understand the evidence for evolution
 Use that evidence to infer evolutionary relationships and build
phylogenetic trees
 Part A focuses on using the three different types of homologies
as evidence for evolutionary relationships

Objectives for Class:
• Use the three different types of homologies as evidence for evolutionary relationships
EVIDENCE FOR EVOLUTION

What is the evidence that all species on earth are
related to each other and share common ancestors?
3 Major Types of Evidence:
1.
Homologous Structures
a) Anatomical homologies and vestigial structures
b) Embryological/ Developmental
c) Molecular/Genetic
2.
Fossils
3.
Geographic Distribution of Species
Objectives for Class:
• Compare and contrast anatomical, genetic, and developmental homologies as evidence for evolution
Evidence: HOMOLOGOUS STRUCTURES
HOMOLOGOUS STRUCTURES

Similar structures due to sharing a common ancestor that
had those structures
Three Types of Homologies:
1. Anatomical (including vestigial traits)
2. Embryological/ Developmental
3. Molecular/ Genetic
Objectives for Class:
• Describe the three different types of homologies and give examples of each
Evidence for Evolution
Begin notes for type of Evidence for Evolution
Anatomical Homology

Similar body parts or bone structures
They don’t necessarily have the same function now, but did in
the common ancestor
 Ex: human arm, cat leg, whale flipper, bat wing all have same
bones

Objectives for Class:
• Compare and contrast anatomical, genetic, and developmental homologies as evidence for evolution
Don’t confuse Homologous Structures
with Analogous Structures

Analogous Structures


structures that have the same function but NOT the same skeletal structure
This suggests these organisms did NOT descend from a common ancestor
with that trait
Ex: insect wing and bird wing
Bird wing
Insect wing
bio.miami.edu
Objectives for Class:
• Compare and contrast anatomical, genetic, and developmental homologies as evidence for evolution
Anatomical Homology: Vestigial Traits

Vestigial Traits
 Don’t
have a function now, but
suggest that they descended from an
ancestor that did use them.

Examples:

www.toptenz.net
human tailbone, human goose bumps,
ostrich wings
Ex: human tail bone, human goose
Objectives for Class:
• Compare and contrast anatomical, genetic, and developmental homologies as evidence
for evolution
animal.nationalgeographic.com
Embryological/Developmental Homology
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
Similar characteristics appearing during specific embryonic/
developmental stages of development
Examples:
 fish, reptile, bird, and human embryos all have gill slits and a tail
(but some lose these features before birth)
Objectives for Class:
• Describe the three different types of homologies and give examples of each
Molecular/Genetic Homology


Comparing the similarities and differences of DNA or
amino acid sequences for different organisms
Closer the similarities = Closer relationships
Objectives for Class:
• Compare and contrast anatomical, genetic, and developmental homologies as evidence for evolution
Phylogenetic Tree for All Living Things
Time -------------------------------------------------------------------->present
Nodes indicate most recent common ancestor of two branches
Evidence for Evolution
Dry Lab: Part B – Day 1
Evolution Dry Lab PART B – Day 1
Part B: Comparing Anatomical and Genetic Evidence

The purpose of this series of lab activities is for you to…
Examine and understand the evidence for evolution
 Use that evidence to infer evolutionary relationships and build
phylogenetic trees
 Part B focuses on comparing and contrasting anatomical and
genetic homologies as evidence for evolution


Complete through Tree # 1 using the evidence for Tree 1
Objectives for Class:
• Compare and contrast anatomical, genetic, and developmental homologies as evidence for evolution
Bio 9C: Friday, 5.6.11
Title: Using homologous structures as evidence for evolution
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Homework:
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No Homework (unless you need to catch-up) 
Do Now(s):
 Label the front right-hand corner of your Evolution Lab B:
 CU = Finished Tree #1 and totally understand how the info in the table
makes the tree
 CD = Finished Tree #1, but don’t understand how the info in the table
makes the tree
 DC = Did not complete the table or the tree
Today’s Objectives:
 Compare and contrast anatomical and genetic homologies as evidence for
evolution
 Describe how fossils are used as evidence for evolution and give one example
that illustrates this
Do Now – Part 2


Which organisms branched off before evolving a complete
digestive tube?
Which three organisms have a brain?
Evolution Dry Lab PART B – Day 2
Part B: Comparing Anatomical and Genetic Evidence
The purpose of this series of lab activities is for you to…




Examine and understand the evidence for evolution
Use that evidence to infer evolutionary relationships and build
phylogenetic trees
Part B focuses on comparing and contrasting anatomical and genetic
homologies as evidence for evolution
Complete Tree #2 and ALL analysis questions
Objectives for Class:
• Compare and contrast anatomical and genetic homologies as evidence for evolution
EVIDENCE FOR EVOLUTION
1. Homologous Structures
a) Anatomical homologies and vestigial structures
b) Embryos
c) Molecular/Genetic
2. Fossils
3. Geographic Distribution of Species
Bio 9C: Monday, 5.9.11
Title: Using fossils as evidence for evolution
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
Homework:
 Reading Guide to movie
Do Now:


What are the differences between Analogous and Homologous structures
Today’s Objectives:
 Describe how fossils are used as evidence for evolution and give one
example that illustrates this.
 Describe how genetic evidence is used as evidence for evolution.
Recap: Analogy vs. Homology

Analogous Structures – similar structures due to
natural selection in similar environments
 common
ancestor did not have it, but descendents evolve
it independently

Homologous Structures – similar structures due to
shared ancestry
 common
ancestor had this feature, so all descendents
have it
 Results from divergent (branching) evolution
DIVERGENT (branching) EVOLUTION
Evidence: FOSSILS

Fossils
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
show species that are now extinct
show transitions to new body forms
Example: Tiktaalik (lived 375 million years ago)
 fish with legs and (maybe) primitive lungs…
 earliest amphibian?
Fossil
Artist Rendering
Objectives for Class:
• Describe how fossils are used as evidence for evolution and give one example that illustrates this.
Evidence: FOSSILS cont.

Example: Archaeopteryx (lived 150 million years ago)
 earliest
bird… but has many dinosaur features
www.ansp.org
Objectives for Class:
• Describe how fossils are used as evidence for evolution and give one example that illustrates this.
Evidence: FOSSILS cont.

Interpreting Fossil Evidence



Fossils form in layers of rock
(older = lower layer)
Fossils in the same layer lived at
the same time
Radiometric dating: determine the
age of a fossil based on how much
radioactive carbon it contains
Objectives for Class:
• Describe how fossils are used as evidence for evolution and give one example that illustrates this.
What lived at the same time as the fossil fish?
Objectives for Class:
• Describe how fossils are used as evidence for evolution and give one example that illustrates this.
What Darwin Never Knew

http://video.pbs.org/video/1372073556

Chapters:
9
- Gene Switches
 10 – A Transitional Form
 11 – Fins to Limbs
 12 (start at 1:26)
Evidence: GEOGRAPHIC DISTRIBUTION

Species that live on the same continents are often closely related to each other

Based on genetic (DNA) and embryonic evidence

This is true, even though they look more similar to species elsewhere.
Example:
North vs. South American rodents
Objectives for Class:
• Describe how fossils are used as evidence for evolution and give one example that illustrates this.
Evidence: GEOGRAPHIC DISTRIBUTION
Example:
Placental Mammals vs.
Australian Marsupial Mammals


Australia has been
separated from other
continents for a long time, so
its marsupials evolved
independently
Marsupial traits are
analogous, NOT
homologous, to placental
mammals
Bio 9C: Tuesday, 5.10.11
Title: Using fossils as evidence for evolution
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
Homework:
 Completed lab is due Thursday at the start of class.
Do Now:


How are fossils used as evidence
Today’s Objectives:
 Describe how fossils are used as evidence for evolution and give one
example that illustrates this.
 Describe how genetic evidence is used as evidence for evolution.
Evidence for Evolution: Part C
How did whales evolve?
9C: Room 107
Crystal
Jamesly
Front of Room
Amando
Carla
Asarel
Julian
Amanjot Obayanna
Anthony
Lilliana
Jason
Rockens
Meryem
Brunyr
Marie
Joe
Sophie
Jhon
Karen
Kendra
Marcus
Garlyn
Christine Jonathan
Evolution Dry Lab PART C – Day1
Part C: How Did Whales Evolve?
The purpose of this series of lab activities is for you to…




Examine and understand the evidence for evolution
Use that evidence to infer evolutionary relationships and build
phylogenetic trees
Part C focuses on using fossil evidence and anatomical homologies to
determine evolutionary relatedness
Complete Tasks 1-4 before watching the video
 You may also have the reading to go along with this video:
 http://www.pbs.org/wgbh/evolution/library/03/4/l_034_05.html
Objectives for Class:
• Describe how fossils and anatomical homologies are used as evidence for evolution
Ambulocetus natans in action
A reconstruction of an early close cousin of whales
Shown here with the kind permission of artist Carl Buell. http://www.indiana.edu/~ensiweb/lessons/whale.ev.html
Bio 9C: Wednesday, 5.11.11
Title: Using fossils as evidence for evolution
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
Homework:
 Complete analysis question for Part C by tomorrow.
Do Now:


Take
Today’s Objectives:
 Describe how fossils are used as evidence for evolution and give one
example that illustrates this.
 Describe how genetic evidence is used as evidence for evolution.
Check the Answers…
Check the Answers…
Evolution Dry Lab PART C – Day2
Part C: How Did Whales Evolve?
The purpose of this series of lab activities is for you to…




Examine and understand the evidence for evolution
Use that evidence to infer evolutionary relationships and build
phylogenetic trees
Part C focuses on using fossil evidence and anatomical homologies to
determine evolutionary relatedness
Complete Task 5 after watching the video
 You may also have the reading to go along with this video:
 http://www.pbs.org/wgbh/evolution/library/03/4/l_034_05.html
Objectives for Class:
• Describe how fossils and anatomical homologies are used as evidence for evolution
Modern Whales…
Where Did Whales Evolve From?
Zooming in on Whale Evolution
Bio 9C: Thursday, 5.12.11
Title: Evolution Review
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
Homework:
 Study for Tomorrow’s Test
 Pass Part C to the left
Do Now:


Today’s Objectives:
 Describe how fossils are used as evidence for evolution and give one
example that illustrates this.
 Describe how genetic evidence is used as evidence for evolution.
EVOLUTION SUMMARY
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

Populations of living things change over time.
Due to change over time, a species can evolve into
one or more new species. This results in the
branching view of the tree of life.
All living things are related because we all evolved
from a common ancestor.
Phylogenetic Tree for All Living Things
Time -------------------------------------------------------------------->present
“There is grandeur in this view of life…” – Charles Darwin
Evolution Review
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
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In your own words, describe the four key steps/ideas of natural selection
and explain how they relate to each other. (you may want to think of this in
terms of an example).
Write a paragraph describing an example of how the steps of natural
selection (above) work in a population (examples could include
hummingbird beaks, finch beaks, antibiotic resistance in bacteria, sickle cell
anemia and malaria, or another example of your choice).
Define what a species is.
In your own words, explain the 2 main steps of speciation (one species
dividing into two species).
Describe at least four types of evidence used to determine evolutionary
relationships between species. Give an example of each!
Interpret or draw phylogenetic trees.
Block 2
Dinosaurs: Return to Life
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

Complete the “guided viewing” packet while watching the video.
Write additional questions on the back of the sheet while viewing
We will follow-up with a short discussion after the movie.
Bio 9C: Friday, 5.13.11
Title: Evolution Test


Homework:
 Now Homework
Do Now:


Put all of your stuff in your bag and zip them up!
Today’s Objectives:
 Assess your understanding of the major concepts from the Evolution Unit