Download Alex Heffron, Jake Jongewaard, and Katie Kerwin

Alex Heffron, Jake Jongewaard, and Katie Kerwin
Biology
11/29/10
per 3
Scientific Essay
Investigation 6
Evolution
How does evolution work? What does the theory of evolution entail? Why does
evolution happen? These are all questions we will answer in this essay. Charles Darwin was the
first to come up with the theory that living things change over time. This process is called
evolution. Evolution happens with the help of genetic mutations passed from generation to
generation. Humans are an example, if you notice we never look exactly the same. This is
because of genetic mutation. There are also changes with the environment. A bird will adapt to
its environment because of natural selection. Natural selection is the concept where a species
that is not adapted to its environment dies off and new strain is created. As an example, the
pocket mouse had to change because of its environment. There were 2 colors of rocks, black
and white. The pocket mouse is considered the “snickers” of the area. The mouse had to adapt
to the two colors of rocks so the predators of the area would not see them. The evidence that
they evolved is the white underbelly of the black mouse, showing that it used to be an all white
mouse. It changed so the predators could not eat them. Our side of the argument is that
evolution does exist.
The environment affects evolution for several reasons. The environment controls the
food that animals get. So animals will have to adapt to get this food sometimes. A good
example of this is the Woodpecker and Large Ground Finches. The Woodpecker finch has a
long and pointed beak, allowing it to get its beak deeply into trees. They also use tools to gather
food. Their beaks allow them to use these tools. They will take a small twig in their mouth, and
shove it into a hole in a tree. They then somehow move around their food. Then they use their
long beak to reach into the hole and pull out whatever food is in there for them. The Large
ground finch has a broader beak used for getting food not available to those with longer,
thinner sort of beaks. This beak helps it to crack hard shells. Both of these finches are very
different from each other. They are still part of the same family of animals. This shows the
evidence of evolution because they both
have different food sources and the ways
they get them influence their beaks. The
climate also affects evolution. The pocket
mouse lives on top of a rocky area that is
a tan. If the mouse crosses over to a rocky area that is black the mouse will adapt to the rock
color and turn black so it doesn’t get eaten by predators. This shows the effect of all of the
different climates on evolution.
Genetic mutations affect evolution by changing the genetic structure of an organism.
As an example, humans all look different. In Hungary, there are some families that walk on all
fours. This is caused by a genetic mutation. It is a rare condition called “Unertan Syndrome”
that does not allow them to walk upright. Another example with humans is how everyone
looks. People always look different. This is caused by genetic mutations. These genetic
mutations happen in the areas where looks change. Sickle cells are a good example of genetic
evolution. The sickle cells are a genetic blood disorder in which red blood cells are
characterized as abnormal, ridged sickle shapes.
The snake head turtle
is another good example of genetic mutation.
These turtles have
grown longer necks to reach food where a
normal turtle may
not be able to get to. The turtles head is also
slimmer so it can put
its head in smaller areas.
Another large part of evolution is natural selection. Natural selection happens when one
trait or species dies off because it is not suited to the environment around it. It may have bad
defense against its predators. It will change its genes to better adapt itself to its environment.
The pocket mouse is a good example of this. They have changed the way they look because of
the two different types of rocks they have to live with, the black and the tan. These mice
changed so they would be better suited to their surroundings. The mouse changed the color of
the fur on the top of its body to protect itself when living on the black rocks. If it had not
changed, the predators could have easily spotted it. It had to change because of natural
selection. The mice that stayed on the black rocks that had black fur lived while when the mice
that had tan fur, when they ventured out on to the black rocks were killed off quickly. Natural
selection kept the black mice on the black rocks and the tan mice on the sand.
This is all the information we have on evolution. Evolution is a topic that ranges
from environmental changes to genetic mutation. We hope that this paper has brought you to
the conclusion that evolution exists.
http://coloradoearthsystemsresearchcollaborative.wikispaces.com/Biology+Investigation+Resources
http://en.wikipedia.org/wiki/Evolution
http://www.pbs.org/wgbh/evolution/
http://evolution.berkeley.edu/
http://www.arkive.org/woodpecker-finch/camarhynchus-pallidus/#text=Description
http://www.doc.ic.ac.uk/~kpt/terraquest/galapagos/wildlife/island/finch.html
http://www.arkive.org/woodpecker-finch/camarhynchus-pallidus/video-08.html
http://www.arkive.org/large-ground-finch/geospiza-magnirostris/video-00.html