Station 1: Fossils
1. What is a fossil? How are fossils formed? Describe at least three different types of fossils.
2. What is the law of superposition and how does it help determine the age of a fossil? Can superposition
alone tell us how long ago a particular fossil formed? (Be careful.)
3. What information can we get from a fossil about the organism that left it?
For three of the pictures of fossils, give one observation about the organism that left it and one inference.
Station 2: Trilobites
1. What changes in body structure occurred in the history of trilobites?
2. Between the Cambrian and the Devonian the fossil record shows an increase in possible predators such
as fish. Do you think there is a relationship between this and the changes we see in body structures?
Explain.
3. Look at the Cambrian trilobites. The body structure of these trilobites did not change for 500 years.
Does this mean that evolution was not occurring? Was natural selection occurring? Explain.
Station 3: Hominid Skull comparison
1. Write down your observations/inferences about the hominid skulls
Station 4: Radioactive Dating
1. In a normal bone, there is 96g of C14. An archaeologist finds a bone and determines there is only 12g of
C14 in it. How old will she say it is?
2. A fossil tooth is dated to be 16,710 years old. It contains 13g of C14 and 91g of C12. How much C14 did
it have originally?
3. You find a fossil clam. A laboratory determines its composition to be 6% C14 and 94% C12. How old is
it?
Station 5: Comparative Anatomy
Analogous Structures
1. Would analogous structures be used to indicate a common ancestor or a different ancestor? Explain.
2. A common saying in biology is “Form Follows Function.” Use this to explain why analogous structures
might occur.
3. Are analogous structures a result of convergent or divergent evolution? Explain.
Vestigial Structures
1. What is a vestigial structure? What are some other examples of vestigial structures in humans or other
species?
2. Suppose you suspected that snakes descended from creature that used to have four legs. What vestigial
structures might you look for to support your hypothesis? Would these prove you were correct?
3. Why are vestigial structures strong evidence for evolutionary relationships?
Homologous Structures
1. Describe the function of each set of bones below:
Animal
Human
Function
Whale
Bird
2. Are the bones arranged in a similar way in each animal? Explain.
3. Why do the same bones appear slightly different between the species?
4. What can homologous structures tell us about the relationships between species?
Comparative Embryology
1. Which statement is most supported by this evidence?
a. Birds go through fish embryo stage followed by a retile embryo stage before becoming a bird
embryo.
b. Birds evolved first from fish and then reptiles.
c. Birds are more similar to retiles than to fish because they share more similarities in genetic
makeup.
2. In what way could you consider this as support for the theories, which propose that birds arose from an
ancient reptile-like animal (theocodont)?
3. What does comparative embryology tell us about relationships between organisms?
Station 6: Comparative Biochemistry
1. Below are 2 diagrams showing the possible relationships between these 4 species. Draw at least 2 more
that you think might be possible.
gorilla
human
chimps
Common
Ancestor
gorilla chimphumans
Common
Ancestor
a. Compare the human DNA to the chimpanzee. Count the number of bases that are not the same
and record in the chart. Repeat with human and gorilla.
Hybridization Data for Human DNA
Human DNA compared to:
Number of matches
Chimpanzee DNA
Gorilla DNA
Common ancestor DNA compared to:
Human DNA
Chimpanzee DNA
Gorilla DNA
Number of matches
Unmatched bases
Unmatched bases
b. How do the gorilla and chimp DNA compare with the human? Which has more similarity?
What does this suggest about the relationship between these three?
c. Does this support any of your hypotheses from #1? Explain.