Name:___KEY______________________ Test Date:_________________ Block:____________
Unit 9: Evolution Study Guide
This study guide must be fully completed in order to be eligible for a re-take.
PART 1: Complete the vocabulary log below.
Word
Definition
The
process
by
which
populations
acquire inherited changes over time
Evolution
Adaptation
Charles Darwin
Mutation
Speciation
Species
Generation Time
Fossil Record
Radiometric Dating
A characteristic that helps an organism survive in its environment
Scientist that developed modern theory of Evolution; said organisms
evolved from a common ancestor
A change in the order of bases in an organisms’ DNA; insertion,
substitution, deletion
The process by which two populations of the same species become so
different that they can no longer interbreed
A group of organisms that can interbreed and produce fertile offspring
The period between the birth of one generation and the birth of the next
generation
A historical sequence of life indicated by fossils found in layers of the
Earth’s crust
A way to find the actual age of rocks or fossils by using the decay rate and
amounts of radioactive material (C14)
Genetic Variation
When organisms in a population differ in certain traits; the traits may be
helpful or harmful
Embryology
Similar organisms share certain characteristics during beginning stages of
development; embryos of vertebrates
Vestigial Structure
The remnant of a once used anatomical structure; may have been helpful at
one time but no longer used for survival
Natural Selection
The process by which organisms with favorable traits survive and
reproduce at a higher rate than other organisms
PART 2: Identify the four steps of natural selection and explain what happens in each stage.
1.
Overproduction: an organism produces more
offspring than can survive to maturity. Ex. A
sea turtle or alligator lay many eggs, but not all
will hatch and survive to adulthood.
3. Struggle to Survive: Offspring will have to fight
for available resources as they grow and develop
(food, water, living space, mates). They may also
face predation. Ex, Baby sea turtles may get
eaten by birds or fish as they go out to sea.
2. Genetic Variation: the offspring will have some
variation (differences) in appearance or
behaviors. Ex. Some sea turtle babies might
have a difference in shell color or size.
4. Successful Reproduction: This is the KEY to
Natural Selection – the organisms that have
beneficial adaptations that aid in survival will
get to reproduce and pass on their genes. Ex.
Baby sea turtles with larger/stronger front
flippers may have an advantage of getting out to
sea faster than others, aiding in survival.
PART 3: Identify the 3 steps of speciation and explain what happens in each step.
1.
Separation: Part of a
population becomes isolated
from the rest. This could be
caused by a geographic
disruption (new mountain range,
canyon, river, lake, etc. or
Environmental reasons (eating,
living, or mating behaviors)
2. Adaptation: The two
groups of the population
slowly adapt to their
changed environment
through natural selection.
Beneficial adaptations aid
in survival.
3. Division: The two populations
of organisms have become so
different that they can no
longer interbreed. This
means that they are no
longer the same species!
PART 4:Identify the 6 pieces of Evidence for Evolution, and explain how they are used to support the
theory of evolution.
Fossil Record: The only way to know
about life forms that are now
extinct. By studying layers of rock,
scientists can identify which fossils
are oldest & most recent by relative
dating.
DNA: Similar organisms have
similar DNA, showing a link to
common ancestry. Mice and
humans share >97% of the same
DNA.
Radiometric Dating: This is a way
that scientists can determine the
exact age of fossils by finding the
amounts of radioactive elements left
in organic material.
Ex. Carbon14 Dating
Comparative Embryology: The
embryos of different vertebrates
are very similar during the earliest
stages of life. Vertebrate embryos
share a few characteristics: gill
slits, tail, backbone and nerve chord.
Anatomical Similarity: Vertebrate
organisms that have a similar
skeletal structure may have come
from a common ancestor.
Ex. A human, bat, dolphin, and cat all
share similar forelimb anatomy.
Vestigial Structures: Sometimes
organisms HAVE structures that
they DO NOT use; These structures
may have been useful at one point in
time, but are no longer needed for
survival.
Ex. Leg bones in whales, Eyespots in
blind mole-rats, Wisdom teeth in
humans.
PART 5: Choose an organism that either lives in a desert or forest biome. Draw a picture of the animal
and label its adaptations. List at least 3 adaptations.
PART 6: Short Answer:
1. The solidified remains or imprint of a previously existing organism is called:
A fossil_________________________________________________
2. Compare the age of fossils found deep in the Earth’s crust compared to those found closer
towards the surface. What type of dating is this?
Fossils found deep in the Earth’s crust are older than fossils found near the surface of the
Earth. This is called relative dating.________________________________
3. Explain why individuals in a population that has traits or abilities that give them a competitive
advantage over other population members are more likely to survive and reproduce.
Individuals with beneficial traits are more likely to get the food and other resources they
need for survival. They might even become more attractive to a mate. These individuals will
be more likely to survive and have successful reproduction.__
4. According to Darwin, the four steps in natural selection are:
__1. Overproduction 2. Genetic variation 3. Struggle to survive
4. Successful reproduction______________
5. The “key” or the most important step of natural selection is_ Successful reproduction _.
6. The opposable thumb allows humans to grasp objects firmly. Because this feature helped
humans to survive over time, it is called a(n)_adaptation___.
7. After 1850, dark peppered moths became more abundant than pale peppered moths. What
factors caused the moths to turn black? Pollution from factories turned tree trunks black;
moths with darker color mutation survived to reproduce
8. A newly formed canyon, mountain range, or lakes are a few of the ways that the first step of
_speciation_ can occur.
9. In order for the American Bald Eagle to produce fertile offspring, who should it mate with
and why? It should mate with a member of its own species or the offspring will not be fertile
and will not be able to reproduce_ _______________
10. If organisms share similar DNA, embryology, and skeletal structures, what does that mean?
__They most likely share a common ancestor___________