The theory of acquired traits is a hypothesis that Jean

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Study Guide – Evolution
1. Who is Darwin and what is he best known for?
British naturalist that came up with the theory of evolution by the
means of natural selection.
2. What is the theory of acquired traits? Give an example of an acquired trait
and an inherited trait.
The theory of acquired traits is a hypothesis that Jean-Baptiste Lamarck
had to explain how organisms evolve. His theory was that organisms do
change over their lifetime. As organisms use and disuse their organs, it
will determine what will become more prominent and passed on to
their offspring. An example of an acquired trait would be an accent in
language or a scar from a cut, or clipping wings short in flies.
3. Where did the common ancestor of the finches come from?
Darwin believed that the common ancestor of the finches came from the
mainland of South America (most likely Ecuador).
4. Define the following terms:
a. Biogeography: The study of where species and their ancestors live.
b. Adaptation: The process by which a population becomes better
suited to its environment
c. Fossil: The ancient remains of an extinct organism
d. Phylogeny: The relationship by ancestry among groups of
e. Divergent evolution: The accumulation of differences between
populations that once formed from a single population (ex: dog
breeds from wolves)
f. Coevolution: The process by which two or more species becomes
more adapted over time to each other’s presence and evolve
together (ex: bacteria and antibiotics)
g. Adaptive radiation: When a new population in a new environment
will undergo evolution until the population fills many parts of the
environment (ex: finch beaks in Galapagos)
5. What does the phrase “survival of the fittest” mean?
Survival of the fittest is the continued existence of organisms that are
best adapted to the environment that enable them to reproduce.
6. What was the main idea of Darwin’s book On the Origin of Species?
The main idea of Darwin’s book, On the Origin of Species, is that species
evolve very slowly over a long period of time through the process of
natural selection.
7. What is the difference between homologous and analogous structures? Give
examples of each.
Homologous structures: similar structure different function ex: wing of
a bird and a human arm
Analogous structures: similar function different structure ex: wing of
bat and wing of butterfly
8. What are vestigial structures? Give an example.
A vestigial structure is an organ that no longer serves a function in the
body of an organism. Ex: human tail bone, pelvis in whales
9. What contributions did the following scientists do to influence Darwin?
a. Hutton: Geologist that explained the Earth is changing and much
older than a few thousand years old
b. Lamarck: French naturalist that supported the idea that organisms
changed over time (lifetime), created the theory of acquired traits.
Darwin later explained that this was false.
c. Wallace: scientist who came up with the same idea of evolution. He
wrote to Darwin and told him about the idea of evolution, pushed
Darwin to publish his book before him
10. What is the difference between natural and artificial selection?
Natural selection – When organisms that are best adapted to their
environment will live and mature. These organisms will then choose
their mate by means of fitness
Artificial selection – when humans choose the traits and control breeding
11. Explain Darwin’s theory of descent with modification.
The theory of descent with modification is the idea that every species
must have descended with small changes over a long period of time by
reproduction from a preexisting species
12. Explain the differences between the finches on the Galapagos Islands and why
they have these adaptations.
Finch beaks are different on each island because of the different food
that is found in their environment. They had to adapt to survive and
through natural selection, new species arouse. Darwin believed they had
a common ancestor because they had many similar internal strucutres.
13. Compare a homologous structure to a modern day species. How would this
show a common ancestry between the species?
By comparing a homologous structure like a bat wing to a human arm
can show common ancestry because the bone structure is very similar
and during development the cells responsible for creating these
structures are the same in each organism. Based on the function of the
organ, the changes begin to differentiate them between organisms. The
common ancestor that each of these organisms shares would have had
the same development in the structure.