UNIT 7 Evolution
sciencepeek.com
Name __________________________________
Date _________________ Period _____
Part 1 - Evolution: What is it and what does it look like in action?
1. Evolution can bee observed by several trials of an experiment with a
population of fruit flies.
a. Define the term population.
b. Outline (bullet point statements) the basic steps of the experiment
to increase starvation resistance in fruit flies.
2. What happened in the fruit fly experiment?
a. Evolution happened. Define evolution.
3. The findings of the experiment are a result of natural selection. This means the flies in subsequent
(future) generations were born with traits or characteristics that that allowed them to:
a. ____________ ____________ and ____________ ____________ than other flies in the population.
4. Evolution occurs then, when ________________ ________________ change in a population over time.
5. Explain what is meant by: individuals don’t evolve, populations evolve [this is an important concept to
understand before moving forward in this unit].
6. Distinguish between microevolution and macroevolution.
7. What is a gene pool?
8. What are allele frequencies?
9. Calculating allele frequencies for a given population.
• The individuals genotypes are as follows:
• 4 AA individuals = _____ A alleles
• 4 Aa individuals = _____ A alleles ______ a alleles
• 2 aa individuals = _____ a alleles
• Total A alleles _____
• Total a alleles _____
• Total # of allele in population _______
a. Calculate the allele frequency of the (A) allele.
b. Calculate the allele frequency of the (a) allele.
Page 1 of 8
UNIT 7 Evolution
sciencepeek.com
Part 2 - How can evolution occur?
Remember evolution occurs when the allele frequencies in a population change.
10. In your own words, define evolution (be sure to include the word population in your definition).
11. Keeping in mind that the allele frequency in a population can change, list the four ways evolutionary
change can occur.
A. _________________________________
B. _________________________________
C. _________________________________
D. Natural Selection [Note: natural selection is not the same as evolution. It is one of the four agents of
change.]
A.—Mutations
12. A mutation is:
13. The causes of mutations are the same for both somatic and
reproductive cells; however, in considering allele frequencies of a
population in studying evolution, we are only concerned with
mutations in reproductive cells, WHY?
14. A mutation can change one allele to a different allele or create a
brand new allele. Describe how this can then affect the resulting
protein product.
B.—Genetic Drift
15. Genetic drift can be defined as:
16. Is the impact of genetic drift seen
more greatly in large populations
or small populations? Explain.
Note: genetic drift is different from
natural selection because its impact
is not directly linked to reproductive
success.
Page 2 of 8
UNIT 7 Evolution
sciencepeek.com
17. Explain the end result of
the founder effect.
18. Explain what happens during
the bottleneck effect
C.—Migration
19. Migration is also called the __________
___________ which is:
20. Can both populations involved experience an
impact? Explain.
Page 3 of 8
UNIT 7 Evolution
sciencepeek.com
Part 3 - How can evolution occur? Continued!!
D.—Natural Selection
21. This chapter introduces us to evolution through natural selection with the fruit fly starvation resistance
experiment. Darwin outlined this agent of change in his famous text. In your words, define natural
selection.
22. There are three specific conditions that need to be present in order for natural selection to occur.
a. Condition 1 is _____________________________, which can include: physical, physiological,
biochemical and behavioral.
b. Condition 2 is _____________________________.
c. Condition 3 is _____________________________. In your own words, summarize this condition:
23. Define sexual selection.
Through natural selection, populations of organisms can become adapted to their environment
24. Since fitness greatly impacts natural selection and evolution, and it doesn’t refer to how fast someone can
run the mile, define fitness in respect to natural selection.
25. In two sentences or less, define the three aspects important to the evolutionary fitness of an individual.
A.
B.
C.
26. Adaptation refers to both ________________________________________________________________
and _________________________________________________________________________________.
27. Natural selection can lead to change but not “perfection.” In your own words, briefly explain the factors that
support this statement: “ A population will never be, what some might consider, perfect.”
Page 4 of 8
UNIT 7 Evolution
sciencepeek.com
Part 4 - Natural Selection can change the traits in a population in several ways
Skipping
Part 5 - Evolution can cause the evolution of complx traits and behaviors
Skipping
Part 6 - Understanding the evidence involved in evolutionary change
The following five unique areas of evidence help us better understand Darwin’s original thoughts and
have advanced all areas of biology
A.—Fossil Record
28. While fossils are often though as “old bones,” technically, fossils are:
29. Briefly explain how radioactive isotopes are utilized in fossil records.
30. List three ways the analysis of fossil records help to provide evidence for
the process of natural selection.
1)
2)
3)
Page 5 of 8
UNIT 7 Evolution
sciencepeek.com
B.—Biogeography
31. Define biogeography in your own words.
32. What is unique about the biogeographic pattern
of some of the organisms in Australia?
Page 6 of 8
UNIT 7 Evolution
sciencepeek.com
C.—Embryology and Anatomy
33. By examining the vertebrate embryo and various aspects
of anatomy, one can identify common features, or
___________________________________________.
34. Briefly explain what a vestigial structure is and list a
common example.
Vampire Bat - Molars (a vestigial structure)
Page 7 of 8
UNIT 7 Evolution
sciencepeek.com
D.—Our DNA
New technology has allowed us to sequence, or map out, our genetic code (DNA). This has also been
successful in many other species.
35. Patterns can be noted in examining the DNA sequence of various organisms. If you were examining the
DNA of a brother and sister, would the sequences look more or less similar than the DNA of the bother as
compared to his cousin?
Why?
36. In examining the beta chain of the hemoglobin protein, it has been found that humans have __________
(number of) amino acids in the beta chain. In comparison:
a. Rhesus monkeys have _________ amino acids that are different as compared to the human
sequence.
b. Dogs have _________ that are different.
c. Birds have _________ that are different.
d. Lamprey eels have _________ amino acids that are different.
37. Explain what the data above means.
Page 8 of 8