Download What Darwin Never Knew Example Answers

Video Points Assignment
1 point for each correct answer; up to 20 points
1.
What did Darwin discover in Argentina?
In Argentina, Darwin discovered fossils that included, skulls, jaws, and backbones that came from giant
mammals that were extinct.
2.
Describe 3 of the animals of the Galapagos Islands and what is unusual about them.
Darwin found three animals to be especially unusual in the Galapagos Islands. He found penguins that
live at the equator and swim in warm waters, giant tortoises that weighed up to 600 pounds that allowed
him to sit on their backs for a ride, and finally the marine iguanas that swim and dive in the sea as
opposed to land iguanas.
3.
What evidence did Darwin have that species change?
Darwin sorted through all of his findings and concluded that all of the different species of birds he
collected were variations of one single bird. Darwin was misled prior to his revelation because each bird
looked so different from the others, for example the shape or size of their beaks. He then knew that
originally there had to be one type of finch or tortoise and overtime it diversified to adapt to the island
they were living on for survival purposes.
4. What did Darwin hypothesize about the origins of life from his study of embryos? (You can use an
example here).
Darwin hypothesized from his study of embryos that there must be a tree of life in creation of species. He
concluded that all species were connected in some way because if one were to look far enough back in the
tree of life, you’ll see that although creatures don’t look anything alike they are deeply connected. Darwin
coined this as decent with modification.
5. How was Darwin’s view of nature different from the standard view of nature from Victorian
times? How did this tie into his idea of natural selection?
In Victorian times, the standard view of nature was sentimental. Darwin found the view of nature to be
savage. Darwin saw that species were constantly struggling for survival that could potentially end in
death. Darwin ultimately saw a pattern and concluded that the creature that survived were those that were
best adapted to the specific environments they lived in. This idea ties into natural selection because by
definition, natural selection is the process in which organisms that are better adapted to their environment
tend to survive and produce more offspring, which is the pattern Darwin saw firsthand when conducting
his studies.
6.
Why do the finches’ beak shapes differ?
The finches’ beak shapes differ because each finch uses their beak for a different purpose. The finches use
their beaks as tools for food and other resources. Darwin saw that on different islands, birds had different
food sources and their beaks would cater to the necessary means to be able to eat the food that they
needed for survival.
7.
Use an example to explain what variation means.
An example of variation could be a litter of kittens or puppies. Although the kittens or puppies came from
the same two parents and developed closely, many do no look the same differing in color and also
physical characteristics such as not being as strong as other puppies or kittens from the litter. Another
example could be fruit grown from the same tree. A lemon tree was produced by one seed but the lemons
can look different in size, shape, color, etc.
8.
Explain how camouflage coloration arose in the Rock pocket mouse.
Camouflage coloration arose in the Rock pocket mouse by different areas within the desert differing in
color. Due to ancient volcanoes erupting, some of the desert is dark rock and others are light rock. Over
time, the mice evolved into a darker color due to living in the dark rock areas, and the mice that stayed in
the light rock areas remained light.
9. Why are mutations neither good nor bad?
Mutations are neither good nor bad because the mutations success strictly depends on the conditions the
organism finds itself in. For example, the dark mouse on the light rock is not beneficial, but when on the
dark rock the mouse can camouflage itself and keep away from predators.
10. How many genes are in the human genome? How does this compare to other organisms?
There are 23,000 genes in the human genome. This number compares to other organisms in the sense that
the amount of genes in a human genome appears to be less than most genes in other organisms. For
example, a simple nematode has the same number of genes as the human genome and some plants have a
considerably larger amount of genes. It shocked researchers because they believed it took a lot more
genes to create a human.
11. Why do some fruit flies have wing spots and others don’t, given that both kinds have the exact same
sequence of DNA in their ‘paintbrush’ gene?
Some fruit flies have wing spots and others don’t because of the way they are using the gene, not because
they didn’t have it. Although both flies have the paintbrush gene, research found that there was a strand of
D.N.A. that differed in those flies that had the wing spots. That stretch of D.N.A. is known as a switch,
which was responsible for turning off the genes that created the spots in the flies that were spotless.
12. How do we know that whales and manatees evolved from 4-legged land creatures that ‘lost’ their legs
and moved back to the sea?
Front flippers of whales have all the bones necessary for a land creature’s arm, and in the back they have
the vestiges of a pelvis. Due to Darwin’s research with D.N.A. and how genes are switched on and off, we
can conclude that evolution is present from land creatures to sea creatures such as whales and manatees.
13. How do finches end up with different beak shapes when they all have the same DNA sequence in
their beak genes?
The different beak shapes are created inside the embryo, specifically within the egg. The different genes
that are turning on and off ultimately decide what kind of finch will be born and decide how the finch will
survive and thrive with the beak it was given. Timing in how long the gene is turned on for and when it
was initially turned on is very important in the creation of the beak.
14. Why was the discovery of the fossil Tiktaalik significant for the study of evolution? Also, describe
the features that made this organism significant.
Tiktaalik’s fossil discovery was significant for the study of evolution because Tiktaalik’s body resembled
a fish’s body, but had a fin-like arm with a flat head. Tiktaalik had a bone structure of those on land, and
was said to be able to push itself up off the substrate either in water or on land. Tiktaalik is significant
because it is 375 million years old and in perfect transitional form, with D.N.A. that has been extinct for a
very long time.
15. What do Hox (homeotic) genes do? How do they explain how a fish obtained legs?
Hox genes are commander genes that give orders that cascade through the developing embryo, activating
entire networks of switches and genes that make up the body. Hox genes are incredibly important in the
development of the shape and form of a developing creature. Hox genes can explain how a fish obtained
legs by the set of Hox genes determining whether or not there is fin development. Interestingly enough,
these genes also command human development of arms and legs and the growth and development of
them.
16. What do ‘switches’ do?
Switches turn genes on and off for specific development, and can switch the orders given by the strongest
genes for the growth and development of characteristics.
17. What makes human hands unique?
The human hand is unique because it holds precision and power and there is nothing like the human hand
existing anywhere else. One important factor of the human hand in the thumb, which allows us to grip and
hold a certain amount of power over things with a lot of strength.
18. Humans have a jaw muscle mutation that apes do not have. How has the jaw muscle mutation been
an evolutionary advantage for humans?
The jaw muscle mutation has been an evolutionary advantage for humans because it allows the human
skull to continue to expand into adulthood, creating a bigger space for our brain.
19. When researchers compared the gene that control brain size development between humans and
chimps, what did they discover?
They discovered that there were radically different genes found in humans compared to chimps. There
have been a large series of mutations, ultimately responsible for the evolution of our big brains.
20. Pollard found that most of the differences in DNA between humans and chimps were in which type
of gene? (circle one).
a. HOX genes
b. Switch genes
c. Protein-coding genes
B. Switch genes