Transcript Evolution

Phenology
Friday
Bloodroot (Sanguinaria canadensis)
• What it is?
Perennial, herbaceous
flowering plant native to eastern
North America that is in bloom
right now.
• What is unique about this
plant? It’s root sap is red and
poisonous and it’s seeds are
dispersed by ants.
• What are its uses?
It’s a
popular red natural dye used by
Native American artists and it is
also found in some dental hygiene
products.
Drill # 5
4/4/14
• How can you use Darwin’s theory of
evolution to explain the following:
1. Bloodroot’s red, poisonous root sap
2. Bloodroot’s relationship with ants
SWBAT:
 Use the fossil record to determine the relative
age of an organism.
 Use comparative anatomy to determine if
species share a common ancestor.
 Describe how to use embryology to determine
which species have the more recent common
ancestor.
 Determine evolutionary relationships by
analyzing amino acids.
Agenda
 Extension from Peppered Moth Lab
 Notes on the 4 Types of Evidence of
Change including fossil records,
comparative anatomy, embryology
and amino acid analysis
Evolution
4 Types of Evidence of Change:
1. Fossil Records
2. Comparative Anatomy
3. Similarities in Embryology
4. Similarities in DNA, RNA and proteins
1. Fossil Records
•
Fossils - the preserved
remnants or impressions
left by organisms that
lived in the past.
•
May bear a resemblance
to organisms that exist
today.
•
Fossil record - the order
in which fossils appear
within sedimentary
rocks.
•
Shells, bones, teeth, etc.
Types of Fossils
Look at the rock cycle and
define sedimentary
rock in your notes.
Dating Fossils
1. Law of Superposition
2. Carbon-14 dating
Law of Superposition
Fossil record creates:
A geologic time scale

Fossils at the bottom of
the strata are older

Fossils at the top of the
strata are younger

A relative age is
determined based on
fossil’s location within
the sedimentary rock
record
Carbon 14 Dating
Age of a fossil is based on the amount of radioactive
carbon that is in the sample (decays to Nitrogen 14)
Example of fossil record
showing evolution
2.
Comparative Anatomy
• Homologous structures

Structures may vary in
function and appear different,
but they all have common
skeletal structures

Indicates that the species share
a common ancestor
As a general rule, the more homologous parts that two
species share, the more closely related they are.
Which two organisms have a closer common
ancestor? Explain.
Comparative Anatomy
• Analogous structures

Structures have identical
function due to similar
environmental pressures

Do not necessarily have a
common ancestor
• Wings in birds and insects
The more complex two structures are, the less
likely that they evolved independently.
Do the organisms below share a common ancestor?
Explain why or why not.
Drill # 6
4/7/14
• Describe the two types of evidence of
evolution we have discussed so far. Define
and give one example.
SWBAT:
 Describe how to use embryology to determine
which species have the more recent common
ancestor.
 Determine evolutionary relationships by
analyzing amino acids.
Homework Due
• Peppered Moth Lab
Agenda
 Finish notes on the 4 Types of
Evidence of Change.
 Evolution Vocabulary WS
 Hand back Animal Fact Sheet
 Amino Acid Analysis (if time)
Homework
 Complete Comparative Anatomy WS
Evolution
4 Types of Evidence of Change:
1. Fossil Records
2. Comparative Anatomy
3. Similarities in Embryology
4. Similarities in DNA, RNA and proteins
Comparative Anatomy
• Vestigial structures

Indicates that the structure
was functional in some
ancestor of the organism

Probably shares a common
ancestor with an organism that
has a functional version of the
same feature
 Appendix in humans
 Pelvic bones in baleen
whales
3.
Similarities in Embryology
•
Early stages of development of different
embryos are very similar to each other
•
More similarities in embryos, the more
recent the common ancestor
Embryo Challenge
Stage I: label
each embryo
• Human
• Hog
• Calf
• Fish
• Tortoise
• Salamander
• Rabbit
• Chick
Embryo Challenge
Stage II: label
each embryo
• Human
• Hog
• Calf
• Fish
• Tortoise
• Salamander
• Rabbit
• Chick
Embryo Challenge
• Answers:
4.
Similarities in DNA, RNA and
proteins
•
The more recently two species have
branched from a common ancestor, the
more similar their DNA and amino acid
sequences.
Wrap up
• Darwin’s theory of evolution by natural
selection explains changes in :
A. individuals
B. genetic makeup
C. populations of species
D. environment
Drill # 4
• How do we know
that animals and
plants have
evolved?
• What types of
evidence can we
see today?
4/4/14