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Evolution Review
Talk about old school!
Question 1
Imagine that you are
Charles Darwin and you
are trying to convince
people that your theory of
natural selection really
does explain how animals
change over time. Use
what you learned about
Galapagos finches, giant
tortoises and/or iguanas
during your voyage to help
support your claim.
Answer 1
• Darwin’s theory of natural selection explains that individuals
that are most fit for their environment are most likely to
survive and pass their beneficial mutations to the next
generation.
• Darwin was able to see slight differences in beak shape
between finches from different islands, which related to the
food available where each species lived.
• The marine and land iguanas have a lot of similarities, but
marine iguanas have learned to eat seaweed instead of land
plants, have a special way of shooting excess salt from their
nose, and blend in with the black rocks near the water.
• Tortoises have different shell shapes depending on the island
they are from. Like the finches, this is based on their food
sources.
Question 2
Your brother thinks that the largest and fastest
individual of a species is most fit to survive.
Explain why you agree or disagree.
Answer 2
• In this case, fitness does not imply big muscles
and the ability to play sports!
• An animal that is fit for it’s environment has
traits that will help it survive. This might mean
that it can run fast, eat from tall trees,
camouflage, fly, etc… It all depends on where
it lives and what it needs to survive!
Question 3
Some whales have been found with a few rear leg
bones that seem random and are unattached to
the rest of their skeletons. Explain why you think
this happens.
Answer 3
• Whales have evolved from land mammals, so
they could still be carriers of the back leg
gene. Maybe it’s just recessive now instead of
dominant!
• It could also be caused by new mutations in
the DNA.
Question 4
Your grandma thinks that the theory of evolution
can't be possible because she has never seen a
monkey turn into a human. How could you
convince her otherwise? Use evidence to support
your claim!
Answer 4
• First of all, monkeys have tails so you’re not a monkey and
neither was your great, great, great, great, great, etc…
grandma because she didn’t have a tail either.
• No primate (monkeys and apes, for example) will ever
turn into a human, especially not overnight. Evolution of
one species takes thousands, if not millions, of years.
These small genetic changes happen over many, many
generations.
• We do share a common ancestor with other modern day
great apes and our DNA is about 97% the same as a
chimpanzee! However, we are still human and they are
not.
• Since we are different species, human and chimpanzees
can’t breed even with such similar DNA. Sorry, no monkey
men as offspring!
Question 5
Explain how a species can
get more genetic variation
and give a specific example
of the results. Why is it
important to have
variation?
Answer 5
• Genetic variation comes from the many
mutations within a species.
• The most common examples are size and
coloration.
• It is important to have genetic variation to
prevent genetic deformities and massive
deaths caused by disease or environmental
change.
Question 6
Using the stratigraphic column below, what can
the rock layers and their contents help you infer
about this evidence?
Answer 6
• These rock layers contain fossils – preserved
evidence of living things.
• According to the Law of Superposition, which
states that rock layers at the bottom of a
stratigraphic column are oldest and younger
layers are above, fossil 5 is oldest and 2 is
youngest.
• This area was most likely under water in the
past.
• Fossils 1 and 4 lived at about the same time.
Question 7
Compare these two pictures
and explain whether or not
you think these species share
a common ancestor. Why or
why not?
Answer 7
• Most likely yes.
• Many dinosaur species evolved into modern
day birds over the last 65 million years. Some
laid eggs, had similar pelvic bones to birds,
almost hollow bones, babies with feathers,
made nests, were warm blooded, etc…
• These two species both have large three-toed
feet, a crest on their heads, somewhat beaklike mouths, walk with a similar stance, etc…
Question 8
Looking at the
following image, which
species is more closely
related to birds, the
Acrocanthosaurus or
the Tyranasaurus? Be
ready to defend your
decision!
Answer 8
• Acrocanthosaurus because it is closer to birds
on the evolutionary tree.
• All three species share the same common
ancestor, Tetanurae.
Question 9
What can you infer about this organism by
looking at the skull below?
Answer 9
• It is a giraffe, but you could not know that for sure
just by looking at the picture. That would be an
inference, not an observation.
• It had horns.
• It had monocular vision (eyes on the side of its
head) so it was probably not a predator.
• The bones are not fully fused together so it was
probably young when it died.
• It had flat teeth that are good for grinding, so it
probably ate plants.
• It had a large nasal cavity (nose hole) so it may have
needed lots of oxygen in each breath.