BIOLOGY
UNIT 8: EVOLUTION
VOCABULARY
1. E __ __ __ __ __ __ __ __, or change over time, is the process by which modern organisms have descended from ancient organisms
2. A scientific T __ __ __ __ __ is a well supported, testable explanation of phenomena that have occurred in the natural world.
3. C __ __ __ __ __ __ D __ __ __ __ __ was an English naturalist who made numerous observations during his travels on the Beagle which led him
to pose a hypothesis about how life changes over time.
4. F __ __ __ __ __ __ are the preserved remains of ancient organisms that provide evidence for how life has changed over time.
5. F __ __ __ __ __ __ is the ability of an individual to survive and reproduce in its specific environment.
6. Any inherited characteristic that increases an organism’s chance of survival, like webbed feet, sharp claws, or speed, is called an
_A_ __ __ __ __ __ __ __ __ __.
7. The process whereby individuals that are better suited to their environment survive and reproduce more successfully is called
N __ __ __ __ __ __ S __ __ __ __ __ __ __ __ , which Darwin nicknamed S __ __ __ __ __ __ __ O __ T __ __ F __ __ __ __ __ __
8. Structures that have different mature forms but develop from the same embryonic tissues are called
H __ __ __ __ __ __ __ __ __ S __ __ __ __ __ __ __ __ __.
9. Homologous structures that are so reduced in size that they no longer function, like the human appendix or legs in snakes, are called
_V_ __ __ __ __ __ __ __ __ organs
10. Choosing to breed cows that produce the most milk or the fastest horses is termed A __ __ __ __ __ __ __ __ __ S __ __ __ __ __ __ __ __.
11. The idea that each living species has descended with changes over time from other species is called D __ __ __ __ __ __ with
M __ __ __ __ __ __ __ __ __ __ __.
12. Charles Darwin’s observations of finches and turtles on the G __ __ __ __ __ __ __ __ Islands led to his Theory of E __ __ __ __ __ __ __ __.
13. Dolphins, penguins, and sharks are distantly-related species that share similar characteristics which help them live in water. This is an
example of C __ __ __ __ __ __ __ __ __ evolution.
14. Even though the Galapagos finches share a common ancestor, they have evolved to fit the ecosystems of their individual islands. This is
an example of D __ __ __ __ __ __ __ __ evolution.
15. A G __ __ __ P __ __ __ is the combined genetic information of all members of a population.
16. Gene flow is affected by M __ __ __ __ __ __ __ __, the movement of individuals in and out of a population.
17. There are two types of G __ __ __ __ __ __ D __ __ __ __, the B __ __ __ __ __ __ __ __ __ E __ __ __ __ __ where the population size suddenly
decreases due to a natural disaster, and F __ __ __ __ __ __ __ E __ __ __ __ __ where few members of a population migrate and begin a new
population.
18. The formation of a new species is known as S __ __ __ __ __ __ __ __ __ .
19. T __ __ __ __ __ __ __ : naming :: C __ __ __ __ __ __ __ __ __ __ __ __ __ : grouping based on characteristics
DARWIN
You are a naturalist who traveled to the Galapagos Islands. Below are excerpts from field notes. Next to each set of notes write a heading. Use
these choices: Overproduction of Offspring, Natural Selection, Struggle for Existence, Variation.
Field Notes
Female finches found on the Galapagos Islands lay enormous
numbers of eggs.
These finches compete for a particular species of insect that inhabits
the small holes found in tree bark.
Some finches’ beaks are long, some are short. The finches with long
beaks are better adapted to remove the insects from the bark.
The finches with the long beaks survive and produce greater
numbers of offspring with long beaks.
Heading
1
Examine the diagram of a side view of sedimentary rocks in the Earth’s crust. Which layer:
a. is the oldest?
b. was formed last?
c. has life forms most like those of today?
d. was formed first?
e. is the youngest?
f. has life forms least like those of today?
Read the following situations below and identify the 5 points of Darwin’s natural selection.
1. There are 2 types of worms: worms that eat at night (nocturnal) and worms that eat during the day (diurnal).
The birds eat during the day and seem to be eating ONLY the diurnal worms. The nocturnal worms are in their
burrows during this time. Each spring when the worms reproduce, they have about 500 babies but only 100 of
these 500 ever become old enough to reproduce.
a.
What worm has natural selection selected AGAINST?
FOR?
Darwin's 5 points: Identify the 5 points in the scenario above.
Population has variations.
Some variations are favorable.
More offspring are produced than survive
Those that survive have favorable traits.
A population will change over time.
2.
There are 3 types of polar bears: ones with thick coats, ones with thin coats and ones with medium coats.
It is fall, soon to be winter. The temperatures are dropping rapidly and the bears must be kept warm, or
they will freeze to death. Many of the bears have had ~2 cubs each but due to the extreme temperatures,
many mothers only have one cub left.
a.
What bear will natural selection select AGAINST?
FOR?
Darwin's 5 points: Identify the 5 points in the scenario above.
Population has variations.
Some variations are favorable.
More offspring are produced than survive
Those that survive have favorable traits.
A population will change over time.
3.
In ostriches, there are 2 types: ones that run fast and those that run slowly. The fast birds can reach up
to 40 miles an hour. Jackals love to eat ostrich, and they can reach speeds of up to 35-40 miles per
hour. A flock of ostrich will lay ~ 10 eggs (each mother only lays 1), but many rodents break into the
eggs and eat the fetus before they hatch.
a.
What ostrich will natural selection select AGAINST?
Darwin's 5 points: Identify the 5 points in the scenario above.
Population has variations.
Some variations are favorable.
More offspring are produced than survive
Those that survive have favorable traits.
A population will change over time.
2
FOR?
Use the following information to answer questions 1-5
Year
1960
1965
1970
1975
1980
1985
1990
1995
# of Species 1
180
184
179
127
104
75
20
0
# of Species 2
150
175
185
221
256
312
335
400
# of Species 3
205
212
225
190
208
210
222
202
1.
Describe what the data above indicates about each species.
2.
Sketch a line graph diagramming the data. Provide a key (legend) for your graph.
3.
What species was best able to adapt? Explain your reasoning.
4.
Which species was least able to adapt? Explain your reasoning.
5.
What do you predict will happen in the next five years? Explain your reasoning.
Suppose a bird eats moths that land on tree trunks. Circle the moths on each of these tree trunks that would probably be eaten by the bird.
Then, answer the following questions by filling in the blanks with the words dark or light.
Which moths in picture:
a. A blend well with the color of the tree trunk?
b. B blend well with the color of the tree trunk?
c. A will be eaten first by the birds?
d. B will be eaten first by the birds?
e. A have the best chance to survive and reproduce?
f. B have the best chance to survive and reproduce?
3
Below are several mutations. After each, write how the trait could be harmful. Then, write how each trait could be helpful.
How trait could be harmful
How trait could be helpful
Albino
squirrel
Hornless
cattle
Short-legged
dog
Long
eyelashes in
humans
EVIDENCE
Complete the chart by checking the kind of evidence described.
Evidence
Homologous
Structure
Analogous
Structure
A modified structure seen among different
groups of descendants.
Human appendix and tailbone
In the earliest stages of development, a tail
and gill slits can be seen in fish, birds,
rabbits, and mammals.
Exemplified by forelimbs of bats, penguins,
lizards, and monkeys.
The forelimbs of flightless birds.
DNA and RNA comparisons may lead to
evolutionary trees.
Bird and butterfly wings have same function
but different structures.
A body structure reduced in function but
may have been used in an ancestor.
4
Type of Evidence
Vestigial
Structure
Embryological
Development
Genetic
Comparisons
CLADISTICS/PHYLOGENY
The table shows the number of amino acid differences in the hemoglobin molecule of
several species compared with amino acids in the hemoglobin molecule of humans.
Using the data in this table as an indicator of degree of relatedness between species,
indicate the position of each species in the evolutionary tree shown below.
Examine the sample cladogram, each letter on the diagram points to a derived character, or something different (or newer) than what was seen
in previous groups. Match the letter to its character. Note: this cladogram was created for simplicity and understanding, it does not represent the
established phylogeny for insects and their relatives.
1. ______ Wings
2. ______ 6 Legs
3. ______ Segmented Body
4. ______ Double set of wings
5. ______ Jumping Legs
6. ______ Crushing mouthparts
7. ______ Legs
8. ______ Curly Antennae
5
To make a cladogram, you must first look at the animals you are studying and establish characteristics that they share and ones that are unique
to each group. For the animals on the table, indicate whether the characteristic is present or not. Based on that chart, create a cladogram.
Cells
Backbone
Legs
Slug
Catfish
Frog
Tiger
Human
DRAWING OF YOUR CLADOGRAM
DRAWING OF YOUR CLADOGRAM
DRAWING OF YOUR CLADOGRAM
6
Hair
Opposable Thumbs