Evolution 2
A: 03/22/10
B: 03/23/10
Warm up
1. What prevents all of the prey from being
eaten?”
2. Pick an animal…then list a behavioral and
an inherited adaptation
3. Write the definition of adaptation in your
own words.
4. What do you know about Natural
Selection?
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Adaptation
• Our characteristics are determined by the
genes we inherit from our parents
• Adaptations are inherited characteristics that
increase survival
Peppered Moths
• Introduction:
• Charles Darwin accumulated a tremendous collection
of facts to support the theory of evolution by natural
selection. One of his difficulties in demonstrating the
theory, however, was the lack of an example of
evolution over a short period of time, which could be
observed as it was taking place in nature. Although
Darwin was unaware of it, remarkable examples of
evolution, which might have helped to persuade
people of his theory, were in the countryside of his
native England. One such example is the evolution of
the peppered moth Biston betularia.
• The economic changes known as the industrial
revolution began in the middle of the eighteenth
century. Since then, tons of soot have been deposited
on the country side around industrial areas. The soot
discoloured and generally darkened the surfaces of trees
and rocks. In 1848, a dark-coloured moth was first
recorded. Today, in some areas, 90% or more of thepeppered moths are dark in colour. More than 70
species of moth in England have undergone a change
from light to dark. Similar observations have been made
in other industrial nations, including the United States.
Peppered Moths Investigation
• We need to design an experiment around the
peppered moth simulation. Take a few
minutes to brainstorm. Here are some things
to think about:
• What question do you want to ask about this
investigation of peppered moth population?
• What is your hypothesis?
• What are some important parts of this
procedure?
• What is the dependant variable and
independent variable?
• What data should we collect? How should we
collect it?
Peppered Moth Simulation
• http:/www.biologycorner.com/worksheets/pepperedmo
th.html
• Objective: Simulate changes in moth population due to
pollution and predation, and observe how species can
change over time.
Instructions:
You will run two simulations for 1 minute each, during
this time you will play the part of a bluejay that eats
moths. After 1 minute record (on scratch paper) the
% of dark moths and light moths - you will need this
information later.
• Run Lichen (light colored) forest
• Run Soot (dark colored) forest
1. Record the moth population percentages.
2. Repeat steps 2-5 for each trial.
3.Analysis - answer all questions on the analysis page.
Data Table
• Create a data table that allows you to record
your data about the moth population.
• You will need to record each trial as well as
what the background color of the tree was.
Definition
Independent
Variable
Dependent
Variable
Hypothesis
Control
Constants
Moth Experiment
Trial
1
2
3
Moth Survival
Light Forest
Moth Survival
Dark Forest
Natural Selection
Natural Selection--Mechanism for evolution (change
over time)
1. Genetic Variation—organisms have different
features determined by different genes
2. Survival of the Fittest—organisms with traits that
“fit” with their environment survive
3. Reproduction—organisms who survive reproduce
and have offspring with the same traits
Analysis Questions
(1). Explain how the color of moths increases or
decreases their chances of survival depending on the
environment.
(2). 500 light colored moths and 500 dark colored
moths are released into a polluted forest. After 2 days
the moths were recaptured, make a prediction about
the number of each type of moth that would be
captured.
• (3). How has the striking change in coloration
come about? (Include an explanation of how
the dark moth appeared and how the
proportion of dark moths changed from
0.0005% to more than 90% in polluted
forests.)
• (4). What underlying law of nature has
produced this change? (Use Darwin's theory
of evolution and apply it to what you have
learned in this investigation.)
Natural Selection
Natural Selection--Mechanism for evolution (change
over time)
1. Genetic Variation—organisms have different
features determined by different genes
2. Survival of the Fittest—organisms with traits that
“fit” with their environment survive
3. Reproduction—organisms who survive reproduce
and have offspring with the same traits
• Genetic variation results in variation in traits
• Over time, DNA changes by mutation
• Bill Nye’s Video: Evolution
• Guided reading
Charles Darwin and Natural Selection
Galapagos
Islands
One of the animals Darwin encountered were
finches, a type of bird. They exhibited a wide range
of beak shapes and sizes.
On your notebook,
please write down and
answer the following
question:
How is it possible for
these different beaks
to exist on a few tiny
islands? Or Why do
these birds have
different beaks…
Honey Bee BCR
• The honey bee in American may develop
immunity to the mites over time, because of
_Natural Selection.
• 1. Genetic Variation
• 2.Surrvival of the fittest
• 3. Reproduction
Acknowledgement
This powerpoint presentation is partly adapted
from Steven Craig at Northwood HS.