Download Evolution Study Guide

Evolution Study Guide
Test Date __________________
Use this worksheet as a guideline to help you study for the upcoming evolution test. Answers
can be found in your textbook, directed readings, notes, and class labs/assignments we
have done during this unit.
1. Explain why this statement is not accurate: “The light peppered moths needed to
adapt to the dark trees after the industrial revolution so they decided to change their
color in order to survive”
Individual moths cannot decide to change their color. The population had 2
varieties (light and dark) because of a random mutation. The dark variety was
able to survive on the dark trees while the light ones were not.
2. On the “tree of life” where are common ancestors found?
Where 2 branches meet (or the point before the two branches split).
3. How do transitional species found in the fossil record support the theory of evolution?
They show how organisms that are living today have changed over time and
how they are connected on the tree of life. The similarities show their
evolutionary relationship.
a. Give an example of a transitional species: Archaeopteryx, Tiktallik,
“Lucy” (A. afarensis), Thrinaxodon, earlier species of whales & horses
4. Give some examples of homologous structures:
Forelimbs of mammals/vertebrates; the gene that codes for eye development
(Pax-6)
a. Explain how homologous structures are evidence for evolution
The similarity of the body parts shows that those animals share a common
ancestor because they have inherited the same traits.
5. What is a vestigial structure? A body part that no longer serves any function
a. Provide one human example and one animal example: Human - Appendix,
tailbone, wisdom teeth, goose bumps, ear muscles; Animal - pelvic bone in
whales and snakes
b. How are vestigial structures evidence of evolution? They show that organisms
have inherited body parts from their ancestors and have evolved to a point
where they no longer need those structures
6. What is Charles Darwin credited with developing? The theory of natural selection
(which was the first correct mechanism for evolution)
a. How did Thomas Malthus, Alfred Wallace, and Charles Lyell influence Darwin?
Malthus pointed out that the human population over-reproduces and there
were more people than what their resources could support. Alfred Wallace
prompted Darwin to publish his book because he had developed the same
theory of natural selection. Charles Lyell was a geologist who figured out that
the Earth was very old and slowly changing.
b. What type of evidence (that is available today) did Darwin lack that help
support his theory? DNA (genetics)
7. What are the steps of natural selection? Overproduction – Inherited Variation –
Struggle to Survive – Successful Reproduction - Adaptation
a. What does “fitness” mean? To have traits/characteristics that allow you to
survive in your environment.
8. What is selective breeding? When humans breed animals or plants in order to get
offspring with a desired trait
a. Give some examples: Different breeds of dogs, different types of cows for milk
production or meat, large fruits, different types of vegetables
9.
List four examples of Natural Selection in Action that we have studied:
Tuskless African Elephants, Insecticide Resistances, Sickle Cell Anemia,
Antibiotic Resistance, Peppered Moths, Darwin’s Finches
a. Pick one example and describe why/how it shows natural selection: People living
in Africa are more “fit” if they have at least one allele for Sickle Cell Anemia
because then they do not die from Malaria. In other parts of the world where
there is no Malaria, most people do not carry the sickle cell allele because it
serves no benefit.
10. What is a mutation? A random change/mistake in the genetic code (DNA)
a. Why do mutations occur? DNA is sometimes copied wrong
b. How do mutations lead to variation in the population? A mutation could
change the gene enough to lead to a different trait that could be passed on to
offspring
11. What are the three steps of speciation? 1. Isolation (or separation) 2. Adaptation
(through Natural Selection) 3. Divergence
a. What are some isolating mechanisms that prevent similar species from
breeding? Different pre-mating rituals (bird songs, fly dances, timing of mating
season) and Post-mating hybrids that are infertile (like a mule or liger)
12. When we compare embryos of vertebrates, what do we notice? Early on they follow
the same developmental steps so they look very similar. Embryos of closely related
species are similar longer in their development.
a. How does embryological development support evolution? It supports the idea
that the embryos follow the same set of instructions that have been passed on
from a common ancestor
13. Explain how studying DNA sequences (genes) helps scientists to determine which
species are closely related. Since DNA can change from mutations, species that
are very closely related have very few differences in their DNA sequence while
species that are not closely related have many differences in their DNA