Download Part One: Are these animals related to each other

Exploring the Evolution
of Vertebrates
Part One: Candy cladograms
Working with your group, arrange your
candy in a phylogenic tree on the back of this sheet.
How can you group your candies together? What
traits do they share?
Part Two: Constructing the Vertebrate
Evolutionary Family Tree
In the center of a piece of large paper, make a cladogram (refer to your book notes/video notes) for
Kangaroos, Humans, Tuna, Bullfrogs, Snapping Turtles, Rhesus Monkeys, and Lampreys.
The cladogram will be based only on shared characteristics between these animals; these characteristics are
found in a chart on the following page. The cladogram you construct will serve as your hypothesis for the evolution of
vertebrates (i.e., the order in which major vertebrate groups branched off from each other).
Part Three: Does DNA Support Your Vertebrate Evolutionary Family Tree?
1. On the back of your poster, make another cladogram for Humans, Kangaroos, Tuna, Snapping
Turtles and Rhesus Monkeys using genetic differences instead of shared characteristics (Refer to the
Handout called Building a Cladogram Using Genetic Differences in Cytochrome C).
2. Compare the two cladograms and decide whether or not amino acid sequences (DNA) support or
refute your original hypothesis.
3. Write a small description on the other (original) side of your poster that explains how amino acid
sequences support your original hypothesis.
Part Four: Individual Activity Assessment
On your own sheet of paper, write a well-developed 5-7 sentences paragraph that:
1. Describe four pieces of evidence that support the evolution (and relationships) among vertebrates.
2. Explains how these activities illustrate that evolution is a theory, not a hypothesis
PART ONE: CANDY CLADOGRAM
In the space below, arrange your candy in a cladogram. How can different candies be grouped?
Use for
Part 2
Shared Characteristics for Vertebrates
Traits
Kangaroo
(Marsupial)
Lamprey
(Jawless Fish)
Rhesus Monkey
(Primate)
Bullfrog
(Amphibian)
Human
Snapping
Turtle
(Reptile)
Tuna
(Jawed Fish)
Dorsal Nerve Cord
Notochord
x
x
x
x
x
x
x
Jaw, Paired Appendages,
Vertebral column
Paired Legs
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
Amnion
Mammary Glands
Placenta
Canine teeth short
Foramen Magnum
forward
(Important Note: An X means the animal HAS the characteristic!)
Traits Key:
Dorsal Nerve Cord: a nerve running along the back or “dorsal” body surface
Notochord: a flexible but supporting cartilage-like rod running along the back or “dorsal/back” surface
Paired Appendages: legs, arms, wings, fins, flippers, antennae, etc…
Vertebral column: backbone
Paired Legs: 2 legs opposite one another
Amnion: a membrane that holds the amniotic fluid surrounding the embryo; may or may not be inside an egg shell
Mammary Glands: milk-secreting glands that nourish the young
Placenta: structure attached to inside of uterus of mother and joined to the embryo by the umbilical cord; provides nourishment
and oxygen to the embryo/fetus
Canine Teeth Short: about same length as other teeth
Foramen Magnum Forward: spinal cord opening located forward under skull (more centered) rather than towards the back of the
skull
Use for
Part 3
Building a Cladogram Using Genetic
Differences in Cytochrome-C
BACKGROUND INFORMATION: You have just completed an activity in which you made a
cladogram showing the evolutionary relationships between seven organisms. The data used to draw
that cladogram was based on shared morphological (anatomical) characteristics that were inherited
from their ancestors.
Biochemical characteristics, like similarities in nuclear DNA, mitochondrial DNA, or protein
structure, can be used to produce cladograms. DNA is the hereditary material in all organisms,
which is mostly located in the nucleus and a small amount in the mitochondria (mitochondrial
DNA). The instructions in DNA are used to link together amino acids in a particular sequence,
which form proteins, and ultimately determine an organism’s traits (i.e., physical features and
behaviors). [DNA → Gene → Amino Acid → Protein → Trait]
If there is strong agreement between the patterns produced using anatomical similarities and those
produced by using biochemical structures, it provides what we call "independent confirmation" of
the cladogram. Independent confirmation is where two or more sources of evidence that are not
dependent on each other produce the same pattern. The more independent confirmation that is
available the more confidence we have that the evolutionary relationships shown in the cladogram
are correct.
In this activity, we will examine and compare the amino acid sequence of a protein called
Cytochrome C. The complete sequence of amino acids for this protein has been determined for
many organisms, including five of the seven animals from your first cladogram.
# of DNA Differences for Cytochrome-C
Human Monkey Kangaroo Turtle Tuna
Human 0
1
12
19
31
Monkey 1
0
13
18
32
Kangaroo 12
13
0
14
27
turtle
19
18
14
0
27
tuna
31
32
27
27
0
(The above chart shows the number of genetic (nucleotide) differences in the genes coding
for the protein Cytochrome C.)
Part Four: Individual Activity Assessment
On your own sheet of paper, write a well-developed 5-7 sentences paragraph that:
1. Describe four pieces of evidence that support the evolution (and relationships) among vertebrates.
2. Explains one reason for why these organisms cannot reproduce together (reproductive isolation).
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