Evolution Term Appendix teacher notes and classroom ready

ahemhootBiotechnology

Dec 5, 2012 (4 years and 11 months ago)

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A1: Teacher notes

Instruction for the Activity:

Classroom will be divided in groups of 2
-
3 and each group will receive a basket full of words and
their corres
ponding answers or
definition.


A1: Teacher notes

Evolution Terms Matching Activity Instructions

Overview

Participants test their knowledge of key terms related to evolution.


Time

5

10 minutes


Materials

"Copies of the “Evolution Terms” activity

"Pencils



Set Up

"Make enou
gh copies of the “Evolution Terms”activity for all participants.



Activity

"Give each participant a copy of the activity.

"Explain to the participants that they are to match the definition with the appropriate term.

"Conduct the activity.

"After five
minutes, ask for participants answers.

"Review the correct answers.



Debriefing

"Which terms were easy to identify? Which

ones were more difficult?

"Why is it important to understand Evolution terms?

"Did this activity help you learn more about the key te
rms related to Evolution?


Activity Instruction for students

Vocabulary Review: Match them ALL!

Match terms, definitions or questions with their corresponding by organizing cards from start to
finish.






Handout with all Definitions

Evolution

A process that

changes populations of organisms
over time. Since evolution ultimately involves
changes in the frequency of heritable traits in a
population, we can define evolution more
precisely as a change in gene frequencies in a
population.


An evolutionary process
that changes anatomy,
physiology, or behavior, resulting in an increased
ability of a population to live in a particular
environment. The term is also applied to
anatomical, physiological, or behavioral
characteristics produced

adaptation

An evolutionary
process that changes anatomy,
physiology, or behavior, resulting in an increased
ability of a population to live in a particular
environment. The term is also applied to
anatomical, physiological, or behavioral
characteristics produced by this process.


g
enetic drift

Change in gene frequencies in a population due to
chance or random events.




natural selection


Differential reproduction and survival of
individuals in a population due to environmental
influences on the population; proposed by Darwin
as th
e primary mechanism driving evolution.



Charles Darwin

The 19th century English scientist who carried
out the necessary research to conclusively
document that evolution has occurred and then
made the idea acceptable for scientists and the
general public.

This man did not invent the idea
of evolution



Darwin's 4 postulates

1. Variation

2. Heritability

3. Differential Reproduction




4. Nonrandom Reproduction



Fitness

Ability to successfully reproduce relative to
your population.

(typically measured as #

offspring)

In Darwin's thinking, the more closely related
two different organisms are, the

More recently they shared a common ancestor.



If two modern organisms are distantly related in
an evolutionary sense, then one should expect
that

They should
share fewer homologous




Gene flow is a concept best used to describe an
exchange between

Populations




Darwinian fitness of an individual is measured
most directly by

The number of its offspring that survive to
reproduce



When we say that an
individual organism has a
greater fitness than another individual, we
specifically mean that the organism

Leaves more viable offspring than others of its
species



Sparrows with average
-
sized wings survive
severe storms better than those with longer or
shorter wings, illustrating

Sparrows with average
-
sized wings survive
severe storms better than those with longer or
shorter wings, illustrating

Stabilizing selectio
n





Appendix: A
-
CRM

Vocabulary Review




Match the terms, definitions or questions with their correct answer by organizing cards from start
to finish.

Term
/Definition/Question

First Word: Evolution



START

Term/Definition/Question



A process that
changes populations of organisms over
time. Since evolution ultimately involves changes in the
frequency of heritable traits in a population, we can
define evolution more precisely as a change in gene
frequencies in a population.



NEXT: adaptation

Term/Definition/Question


An evolutionary process that changes
anatomy, physiology, or behavior, resulting
in an increased ability of a population to
live in a particular environment. The term
is also applied to anatomical, physiological,
or behavioral cha
racteristics produced by
this process.


NEXT:
genetic drift

Term/Definition/Question



Change in gene frequencies in a population due to
chance or random events.






Next:
natural selection

Term/Definition/Question


Differential reproduction and survival

of
individuals in a population due to
environmental influences on the
population; proposed by Darwin as the
primary mechanism driving evolution.


Next
: Charles Darwin

Term/Definition/Question


The 19th century English scientist who carried out the
necess
ary research to conclusively document that
evolution has occurred and then made the idea
acceptable for scientists and the general public. This
man did not invent the idea of evolution.


Next:

Darwin's 4 postulates

Term/Definition/Question


1. Variation

2
. Heritability

3. Differential Reproduction

4. Nonrandom Reproduction


Next
:

Fitness

Term/Definition/Question

Ability to successfully reproduce relative to your
population.

(typically measured as # offspring)

Next

:
In Darwin's thinking, the more closely

related
two different organisms are, the


Term/Definition/Question


Term/Definition/Question





More recently they shared a common
ancestor.


Next: If two modern organisms are
distantly related in an evolutionary sense,
then one should expect that


They
should share fewer homologous



Next: Gene flow is a concept best used to describe an
exchange between

Term/Definition/Question


Populations



Next: The Darwinian fitness of an
individual is measured most directly by

Term/Definition/Question


The number o
f its offspring that survive to reproduce


Next: When we say that an individual organism has a
greater fitness than another individual, we specifically
mean that the organism

Term/Definition/Question


Leaves more viable offspring than others
of its
species


Next: Sparrows with average
-
sized wings
survive severe storms better than those
with longer or shorter wings, illustrating

Term/Definition/Question


Stabilizing selection



Next: GMO’s








Appendix: B
-
TN

Teacher will provide the instruction
for students to complete their KWL chart. K=What you
KNOW, W=What you want to Know, and L=What you learned.

Teacher will be walking around to observe students answer and what they are interested in learning.
Teacher requests student to find a partner sit
ting to partner up with a student sitting beside or
behind and share with them your “W” column
-
what you want to know. Students will be asked to add
to column L during and after watching the GMO video.
























Appendix: B
-
Classroom ready materi
al

(KWL) Chart

Task: In the space provided, share what you know about GMO’s (Genetically Modified Food), and
what you want to learn before watching the video
(4 min)
. After completing the first two column,
“Talk Partner” for 1 (min) and share what you know and what you want to know. During and after
watching the video complete the last column called What I learned?
(5 min)

Youtube Video Link:
http://www.doctoroz.com/videos/genetically
-
modified
-
foods
-
pt
-
1








I keep my eyes and ears open
to learn new things.

WHAT I “KNOW”

What I “WANT” TO KNOW

WHAT I “LEARNED”
































Appendix C 1: Teacher Notes

What is Biotechnology? How does it link to Natural Selection


Explain to the students that biotechnology is a way of using the

characteristics of microbes and plant and animal cells for the perceived benefit of mankind.


Humans have been using biotechnology for thousands of years in the form of cross breeding,
eg

-

a farmer notices that certain sheep in a herd give birth easily to lambs




or they grow better wool than others. Hewill then breed from these lambs to establis
h a flock
ofsheep that all have these wanted characteristics.

-

Cite the example of a breed of dog, the long haired daschund, established over 100 years ago by
cross breeding daschunds and cocker spaniels


ask students to think of any possible negative effects of animal cross breeding,
eg
hip dysplasia in
many german shepherd dogs?


Ask them what are the positive aspects of cross breeding?

Can they cite any negative effects?

Appendix C 2: Video Link
-

http://www.doctoroz.com/videos/genetically
-
modified
-
foods
-
pt
-
1



Appendix D: Artificial Selection Lecture


Teacher Notes


[2] “What words come to mind when you think of artificial se
lection?”



Prompt students with referral to prior knowledge, evolution, natural selection


[5]

Animal breeders may also change the characteristics of domestic animals by selecting for
reproduction those individuals with the most desirable qualities


[6] R
eferring back to the last point about artificial selection:


i.

H
OW IS ARTIFICIAL SEL
ECTION SIMILAR TO NA
TURAL SELECTION
?

This process
causes evolutionary change
in the organism and is similar to natural selection
only with humans, not nature, doing the
selecting.


ii.

W
HAT FEATURES OR MECH
ANISMS THAT DEFINE A
RTIFICIAL SELECTION
MAKE IT SIMILAR TO
NATURAL SELECTION
?

When you select for certain characteristics in a certain organism, only those genes will be
passed on to future generations. Those species will
eventually evolve based on those
particular traits.


iii.

H
OW COULD ARTIFICIAL
SELECTION BE CONSIDE
RED AN EVOLUTIONARY
EVENT
?

Over longer period of time, similar to natural selection (where the best and fittest traits
outcompete other traits to allow the organi
sm to survive its conditions) artificial selection
involves humans actively selecting the genes/traits appropriate for their purpose or
environment, which places a focus on those traits and thereby leads to reproduction only of
those traits.


[7]

These pl
ants have been modified in the laboratory to enhance desired traits such as increased
resistance to herbicides or improved nutritional content.

--

They are created using biotechnology…
Application of scientific and technical advances in life
science to dev
elop commercial products




--

There are different branched of biotechnology, blue


marine/aquatic applications, red


medical
processes, white


industrial processes, and green


agricultural practices


[8]

Traditionally: the enhancement of desired traits
has been achieved through
breeding


But conventional plant breeding methods can be very
time consuming
and are often
not very
accurate


[10]

B.t., or
Bacillus thuringiensis
, is a naturally occurring bacterium that produces crystal
proteins that are lethal

to insect larvae. B.t. crystal protein genes have been transferred into corn,
enabling the corn to produce its own pesticides against insects such as the European corn borer.


[13]

40 plant varieties commercialized by the government including: tomatoes a
nd cantalopes have
modified ripening characteristics, soybeans and sugarbeets resistant to herbicides and corn and
cotton plants with increased resistance to insect pests


Not all these products are available in supermarkets yet; however, the prevalence of

GM foods in
U.S. grocery stores is more widespread than is commonly thought.


Highly processed foods, such as vegetable oils or breakfast cereals, contain some tiny percentage
of genetically
-
modified ingredients because the raw ingredients have been pool
ed into one
processing stream from many different sources.


[14] What are some of the advantages of GM foods?

The world population has topped 6 billion people and is predicted to double in the next 50 years.
Ensuring an adequate food supply for this boomin
g population is going to be a major challenge in the
years to come. GM foods promise to meet this need in a number of ways:



Pest resistance


-
Crop losses


resulting in devastating financial loss for farmers and starvation in
developing

countries.

-
Farmers typically use many tons of chemical pesticides annually.

-
Consumers do not wish to eat food that has been treated with pesticides because of
potential

health hazards

-
run
-
off of agricultural wastes from excessive use of pesticides and fertilizers can poison
the water

supply and cause harm to the environment.




-
Growing GM foods such as B.t. corn can help eliminate the application of chemical
pesticides

and reduce the c
ost of bringing a crop to market



Herbicide tolerance

-
farmers will often spray large quantities of different herbicides (weed
-
killer) to destroy
weeds, a

time
-
consuming and expensive process, that requires care so that the herbicide doesn't
harm the

crop plant or the environment.

-
Crop plants genetically
-
engineered to be resistant to one very powerful herbicide could
help prevent environmental damage by reducing the amount of herbicides needed.

-
For example, Monsanto has created a strain of soybeans

genetically modified to not be
affected by their herbicide product Roundup
.
A farmer grows these soybeans which then only
require one application of weed
-
killer instead of multiple applications, reducing production cost and
limiting the dangers of agricul
tural waste run
-
off



Disease resistance


-
There are many viruses, fungi and bacteria that cause plant diseases. Plant biologists are
working

to create plants with genetically
-
engineered resistance to these diseases
8
,



Cold tolerance


-
Unexpected frost can destroy sensitive seedlings. An antifreeze gene from cold water fish
has

been introduced into plants such as tobacco and potato.

-
With this antifreeze gene, these plant
s are able to tolerate cold temperatures that
normally would

kill unmodified seedlings






Drought tolerance/salinity tolerance


-
As the world population grows and more land is utilized for housing instead of food
production, farmers will need to grow cro
ps in locations previously unsuited for plant cultivation.
Creating plants that can withstand long periods of drought or high salt content in soil and
groundwater will help people to grow crops in formerly inhospitable places
11
,
12
.



Reduced maturation date


-
for crops, this will yield products fastersand at high rate



Nutrition


-

Malnutrition is common in third world countries where impoverished peoples rely on a
single crop such as rice for the main staple of their diet. However, rice does not contain adequate
amounts of all necessary nutrients to prevent malnutrition. If rice c
ould be genetically engineered
to contain additional vitamins and minerals, nutrient deficiencies could be alleviated.



Pharmaceuticals


-
Medicines and vaccines often are costly to produce and sometimes require special storage

conditions not readily a
vailable in third world countries.

-
Researchers are working to develop edible vaccines in tomatoes and potatoes
16
,
17
. These
vaccines

will be much easier to ship, store and administer than traditional injectable vaccines.



Phytoremediation

Not all GM plants are grown as crops. Soil and groundwater pollution continues
to be a problem in all parts of the world. Plants such as poplar trees have been genetically
engineered to clean up heavy metal pollution from contaminated soil
18
.






[15]
What are some of the criticisms against

GM foods?


Environmental hazards


Unintended harm to other organisms


-
Last year a laboratory study was published in
Nature
21

showing that pollen from B.t. corn
caused high mortality rates in monarch butterfly caterpillars. Monarch caterpillars consume
milkweed plants, not corn, but the fear is that if pollen from

B.t. corn is blown by the wind onto
milkweed plants in neighboring fields, the caterpillars could eat the pollen and perish.

-
Although the Nature study was not conducted under natural field conditions, the results
seemed to support this viewpoint. Unfort
unately, B.t. toxins kill many species of insect larvae
indiscriminately; it is not possible to design a B.t. toxin that would only kill crop
-
damaging pests and
remain harmless to all other insects.

-
This study is being reexamined by the USDA, the U.S. En
vironmental Protection Agency
(EPA) and other non
-
government research groups, and preliminary data from new studies suggests
that the original study may have been flawed
22
,
23
. This topic is the subject of acrimonious debate,
and both sides of the argument are defending their data vigorously. Currently, there is no
agreement about the results of thes
e studies, and
the potential risk of harm to non
-
target
organisms will need to be evaluated further.




Reduced effectiveness of pesticides

-

Just as some populations of mosquitoes developed resistance to the now
-
banned pesticide
DDT, many people are con
cerned that insects will become resistant to B.t. or other crops that have
been genetically
-
modified to produce their own pesticides.



Gene transfer to non
-
target species


-
Another concern is that crop plants engineered for herbicide tolerance and weeds

will
cross
-
breed, resulting in the transfer of the herbicide resistance genes from the crops into the
weeds. These "superweeds" would then be herbicide tolerant as well.

-
Other introduced genes may cross over into non
-
modified crops planted next to GM cr
ops.

-
The possibility of interbreeding is shown by the defense of farmers against lawsuits filed
by Monsanto. The company has filed patent infringement lawsuits against farmers who may have



harvested GM crops. Monsanto claims that the farmers obtained Mon
santo
-
licensed GM seeds from
an unknown source and did not pay royalties to Monsanto. The farmers claim that their unmodified
crops were cross
-
pollinated from someone else's GM crops planted a field or two away. More
investigation is needed to resolve this

issue.

-
There are several possible solutions to the three problems mentioned above. Genes are
exchanged between plants via pollen. Two ways to ensure that non
-
target species will not receive
introduced genes from GM plants are to create GM plants that are

male sterile (do not produce
pollen) or to modify the GM plant so that the pollen does not contain the introduced gene
24
,
25
,
26
.
Cross
-
pollination would not occur, and if harmless insects such as monarch caterpillars we
re to eat
pollen from GM plants, the caterpillars would survive.

-
Another possible solution is to create buffer zones around fields of GM crops
27
,
28
,
29
. For
example, non
-
GM corn would be planted to surround a field of B.t. GM corn, and the non
-
GM corn
would not be harv
ested. Beneficial or harmless insects would have a refuge in the non
-
GM corn, and
insect pests could be allowed to destroy the non
-
GM corn and would not develop resistance to B.t.
pesticides. Gene transfer to weeds and other crops would not occur because t
he wind
-
blown pollen
would not travel beyond the buffer zone. Estimates of the necessary width of buffer zones range
from 6 meters to 30 meters or more
30
. This planting method
may not be feasible if too much
acreage is required for the buffer zones.


Human health risks


Allergenicity


-
Many children in the US and Europe have developed life
-
threatening allergies to peanuts
and other foods. There is a possibility that introducin
g a gene into a plant may create a new
allergen

or cause an allergic reaction in susceptible individuals.

-
A proposal to incorporate a gene from Brazil nuts into so
ybeans was abandoned because of
the fear of causing unexpected allergic reactions
31
. Extensive testing of GM foods may be
required to avoid the possibility of harm to consumers with food allergies.



Unknown effects on human health


-
There is a growing concern that introducing foreign genes into food plants may have an
unexpected and
negative impact on human health.

-
On the whole, with the exception of possible allergenicity, scientists believe that GM foods
do not present a risk to human health.


Economic concerns




Bringing a GM food to market is a lengthy and costly process, and of c
ourse agri
-
biotech
companies wish to ensure a profitable return on their investment.

-
Many new plant genetic engineering technologies and GM plants have been patented, and
patent infringement is a big concern of agribusiness.

-
Yet consumer advocates are
worried that patenting these new plant varieties will raise the
price of seeds so high that small farmers and third world countries will not be able to afford seeds
for GM crops, thus widening the gap between the wealthy and the poor.

-

One way to combat
possible patent infringement is to introduce a "suicide gene" into GM
plants. These plants would be viable for only one growing season and would produce sterile seeds
that do not germinate. Farmers would need to buy a fresh supply of seeds each year. Howev
er, this
would be financially disastrous for farmers in third world countries who cannot afford to buy seed
each year and traditionally set aside a portion of their harvest to plant in the next growing season.
In an open letter to the public, Monsanto has
pledged to abandon all research using this suicide
gene technology
35
.


Extra information: GM Products: Benefits and Controversies (Good for debate)

Benefits



Crops


o

Reduced maturation time

o

Increased nutrients, yields, and stress tolerance

o

Improved resistance to disease, pests, and herbicides

o

New products and growing techniques



Animals


o

Increased resistance, productivity, hardiness, and feed efficiency

o

Better yiel
ds of meat, eggs, and milk

o

Improved animal health and diagnostic methods



Environment


o

"Friendly" bioherbicides and bioinsecticides

o

Conservation of soil, water, and energy

o

Bioprocessing for forestry products

o

Better natural waste management

o

More effici
ent processing



Society


o

Increased food security for growing populations

Controversies



Safety


o

Potential human health impacts, including allergens, transfer of antibiotic resistance
markers, unknown effects

o

Potential environmental impacts, including: unintended transfer of transgenes
through cross
-
pollination, unknown effects on other organisms (e.g., soil microbes),
and loss of flora and fauna biodiversity



Access and Intellectual Property





o

Domination of world food production by a few companies

o

Increasing dependence on industrialized nations by developing countries

o

Biopiracy, or foreign exploitation of natural resources



Ethics


o

Violation of natural organisms' intrinsic values

o

Tampering wi
th nature by mixing genes among species

o

Objections to consuming animal genes in plants and vice versa

o

Stress for animal



Labeling


o

Not mandatory in some countries (e.g., United States)

o

Mixing GM crops with non
-
GM products confounds labeling attempts



So
ciety


o

New advances may be skewed to interests of rich countries


[18]

Genetically
-
modified foods have the potential to solve many of the world's hunger and
malnutrition problems, and to help protect and preserve the environment by increasing yield and
r
educing reliance upon chemical pesticides and herbicides. Yet there are many challenges ahead for
governments, especially in the areas of safety testing, regulation, international policy and food
labeling. Many people feel that genetic engineering is the i
nevitable wave of the future and that we
cannot afford to ignore a technology that has such enormous potential benefits. However, we must
proceed with caution to avoid causing unintended harm to human health and the environment as a
result of our enthusias
m for this powerful technology.
























Appendix E1
-

teacher’s Notes

Teacher Guide: Evolution: Natural and Artificial Selection

Learning Objectives

Students will …



Use artificial selection to develop a new variety of insects.



Distinguish
between the processes of natural and artificial selection.



Compare the rates at which natural and artificial selection occur.



Explore how the rate of mutations is related to the rate of adaptation to an environment.


Vocabulary

artificial

selection, breed, chromosome, evolution, fitness, genotype, mutation, natural selection,
phenotype


Lesson Overview

Ever since prehistoric humans first domesticated animals over
12,000 years ago, people have tried to breed animals and
plants tha
t have desirable traits. Over thousands of years,
the process of
artificial selection

has led to remarkable
diversity within species such as dogs and cattle, as well as
crop plants such as rice and wheat.









The
Evolution: Natural and Artificial Selection
Gi
zmo™ allows
students to explore the process of artificial selection and
compare its outcomes to the results of natural selection.


The
Evolution: Natural and Artificial Selection
Gizmo was designed as a follow
-
up to the
Evolution:
Mutation and Selection
Gi
zmo. We recommend you do that activity before this one.


The Student Exploration sheet contains Two activities:



Activity A


Students compare the processes of natural and artificial selection.



Activity B


Students investigate how the mutation rate affects

evolution (Homefun)



Suggested Lesson Sequence


1.

Pre
-
Gizmo activity: Domesticated breeds


Linked to video

What is biotechnology

2.

Divide the class into groups, and have each group do a brief Internet investigation of a
domestic animal such as dogs, cats, horses, cows, pigeons, pigs, sheep, and so forth. Each
group can present a slideshow of images that illustrate the wide variety of
breeds of that
animal that can be found. (If you like, you could also examine varieties of domestic plants
such as apples and lettuce.)


After the presentations, discuss how selective breeding occurs. Starting with wild animals
and plants, how did breeder
s develop such a variety of shapes, sizes, colors, and other
characteristics?


2.Gizmo activities







(

15


20 minutes per activity)

Assign students to computers. Students can work individually or in small groups. Ask
students to work thro
ugh the activities in the Student Exploration using the Gizmo.
Alternatively, you can use a projector and do the Exploration as a teacher
-
led activity.


3.

Discussion questions








(

15


30 minutes)






As students are working or just after they a
re done, discuss the following questions:



Which process tends to work more efficiently, natural selection or artificial
selection? Why do you think that is?



What is the role of mutation in evolution? What is the role of chance in evolution?



What are the l
imits of artificial selection?



In which situations is it an advantage for a population to have a high mutation rate?
In which situations is a high mutation rate a disadvantage?



In what ways do you think the Gizmo simulation is realistic? In what ways is th
e
Gizmo simulation unrealistic?


4.

Follow
-
up activity: Combining data


(Done as a group
)

In the
Evolution: Natural and Artificial Selection

Gizmo, chance plays a huge role in how
quickly the population of insects adapts to it environment or becomes a certain color. If the
right mutations crop up, the population can change very quickly. If helpful mutations do not
occur, it may take several hu
ndred generations for the population to change its color. Even
if a helpful mutation appears, it could disappear quickly if the mutated insect is eaten or if
the mutated chromosome is not inherited by any of the offspring.


To offset the effects of chance,

have your students combine their data in each of the
experiments described in the Student Exploration. By averaging data from a large number
of trials, students will be able to get a more accurate picture of how quickly artificial and
natural selection oc
cur, as well as a better idea of the effects of mutation rate on evolution.

Scientific Background

Artificial selection

is a term coined by Charles Darwin to describe the breeding of animals and
other organisms by humans. In this process, a breeder selects which individuals to breed together,
with the purpose of perpetuating desirable traits and eliminating undesirable tra
its. Darwin
contrasted artificial selection with
natural selection
, in which nature selects the parents.


Humans have been breeding animals and plants for over 12,000 years. The first domesticated
animals were probably dogs. Although theories vary, it is p
ossible that stone
-
age humans used dogs
to help with chasing and trapping large animals. Once the animal was cornered, humans could
complete the kill with spears and other primitive weapons.





Other animals and plants were domesticated as human societies beg
an to abandon a hunter
-
gatherer lifestyle and use agriculture to supply food. Sheep and cattle were domesticated around
9,000
B
.
C
.
, and crops such as gourds, peas, and wheat were first grown at this time.


Two main methods are used to develop new varietie
s of plants and animals:
hybridization

and
inbreeding
. When two dissimilar animals or plants are mated, the resulting offspring are
hybrids
.
For example, horses and donkeys can be bred to produce hybrid mules. Mules are healthy and
vigorous but almost alwa
ys infertile. Hybridization is more common among plants than animals. Many
hybrid plants are fertile and can combine desirable properties from both parent plants.


Inbreeding is used to spread a desirable trait in a variety of animals or plants. When a des
irable
trait is identified, only animals possessing that trait are allowed to breed. This results in the
breeding of many close relatives, a practice that can lead to
inbreeding depression
. Many rare
genetic disorders are carried by recessive alleles. In a

large and diverse population, the probability
that two healthy carriers of a rare deleterious allele will mate and produce defective offspring is
extremely small. If the recessive allele exists in a very tiny breeding population, however, the
probability
of two carriers mating becomes much higher. The term
hybrid vigor

refers to the fact
that hybrids are often healthier than their purebred counterparts.

Historical Connection: Darwin and artificial breeding

As he created his theory of evolution by nat
ural selection, Charles Darwin was inspired by a wide
variety of sources, from his observations of South American wildlife and fossils as a young
passenger aboard the
H.M.S Beagle
, to the works of the economist Thomas Malthus. A third major
source of inspi
ration for Darwin came from his observations of domestic animal breeds in the
countryside around Down House, his home outside of London.

Beginning in the 1830s, Darwin delved deeply into the selective breeding of plant and animal
varieties. He carried out
his own breeding experiments and thought of artificial selection as an
ideal analogy for natural selection. The first chapter of
The Origin of Species

is devoted to
artificial selection, and Darwin later wrote
Variation of Animals and Plants under
Domestication
.

Ironically, Darwin’s family may have been victimized by inbreeding depression. Darwin married his
first cousin, Emma Wedgwood. Several of their children experienced mysterious health problems,
and three of them died before reaching adulthoo
d.

Selected Web Resources

Artificial selection:
http://evolution.berkeley.edu/evosite/lines/IVAartselection.shtml






Natural selection:
http://www.actionbioscience.org/evolution/futuyma.html

Domestication:
http://www.historyworld.net
/wrldhis/PlainTextHistories.asp?historyid=ab57


Hybrids:
http://waynesword.palomar.edu/hybrids1.htm

Artificial selection activities:
http://www.pbs.org/wgbh/nova/teachers/activities/3103_dogs.html
,

http://www.pbs.org/wnet/nature/lessons/the
-
perfect
-
cow/lesson
-
overview/1491/

Char
les Darwin:
http://www.visionlearning.com/library/module_viewer.php?mid=111
,
http://findarticles.com/p/articles/mi_m1134/is_9_114/ai_n15855369/?tag=content;col1

Related Gizmos:

Evolution: Mutation and Selection
:
http://www.explorelearning.com/gizmo/id?554

Natural Selectio
n
:
http://www.explorelearning.com/gizmo/id?447

Rainfall and Bird Beaks
:
http://www.explorelearning.com/gizmo/id?404





Appendix

E2
-
Clas
s room Ready Material

Gizmo Handout

Activity A:


Artificial selection

Get the Gizmo ready
:



Select

Artificial selection
.



Set the
mutation rate

to 2.0.



Question: How can a species be changed through artificial selection?



1.

Set a goal
: In this activity,

your goal is to develop insects that are any color you would like.


What color do you want your insects to be?

Blue
, Green, or Red






2.

Make a plan
: Follow the directions in the Gizmo to produce five generations of insects.




How would you describe the process of artificial selection?




This is the process where humans choose the male and female based on
desirable characteristics.



Artificial selection is also known as selective breeding or abnormal selection.
It is a process o
f selective breeding in plants, animals and other organisms.
Artificial selection is the procedure of breeding for certain traits. Humans
individually select suitable parents in order to perpetuate certain desired
traits and to eliminate others




How will m
utations be useful in achieving your goal color?



mutations

are changes in a
genomic sequence
: the
DNA

sequence of a
cell's
genome

or the DNA. Therefore, is similar to abnormal selection.



What strategy will you use to produce insects of your desired color?



Change background to different colour because it will increase
insects
vulnerability to be detected and preyed. Hence, it will lead to mutation
of specific gene that would encourage mimicry.


3.

Run Gizmo
: Use the Gizmo to produce insects that match your goal color. (This will take
patience!) When you are satisfied, cli
ck the
camera

(
) to take a snapshot. Paste the snapshot
into a blank document that you will turn in with this worksheet.


How many generations did it take for you to develop your insects? ____________________


4.

Compare
: If possible, compare your insects to

the insects developed by your classmates. What
different colors of insects can be developed using artificial selection?
______________________________________________________________________




(Activity A

continued on next page)


5.

Collect data
: Use the
red
,
green
, and
blue

sliders to match the
Background color

as closely as
possible to phenotype of the insects. Select
Natural selection
.


Click
Play
, and then click
Pause

when the
Average fitness

first exceeds 90%. Record the
number of generations in the table

below, and then repeat for a total of five trials.


Trial

1

2

3

4

5

Mean

Number of generations to
achieve 90% fitness









6.

Calculate
: Add up the number of generations and divide by five to find the mean number of
generations required to reach at
least 90% fitness. Fill in the last column of the table.



7.

Analyze
: Which process tends to occur more quickly, natural selection or artificial selection?
Why do you think this is so?



8.

Summarize
: How are the processes of natural selection and artificial
selection similar? How are
they different? If possible, discuss your answer with your classmates and teacher.




Activity B: Home
fun


Mutation rates

Get the Gizmo ready
:



Click
Reset
(
). Be sure
Natural selection
is
selected.



Set
red

to 10
0,
green

to 255, and
blue

to 50.



Question: How does the mutation rate affect a population’s ability to adapt to its
environment?


1.

Gather data
: Change the
mutation rate

to 0.1 and the
Sim. speed

slider to its lowest setting.
Click
Play
, and then click
Pause

when the offspring appear. Record the number of mutations
(circled offspring), and then repeat for two more trials. Do this for each mutation rate listed in
the table, then calculate the mean number of mutations for each mutation rate.


Mutation rate

Trial 1

Trial 2

Trial 3

Mean

0.1





1.0





10.0






How does the mutation rate relate to the number of mutations in each generation?


2.

Form hypothesis
: How do you expect the rate of mutations to affect the ability of the bug
population to adapt to its environment?


3.

Gather data
: Click
Reset
. Set the
mutation rate
to 0.1, and move the
Sim. speed
slider to a
faster setting. Click
Play
, and then click
Paus
e
when the
Average fitness

is 90% or greater.
Record the number of generations required to reach 90% fitness in the table below.


Mutation rate

Number of generations to 90% average fitness

Mean

Trial 1

Trial 2

Trial 3




0.1





0.3





0.5





1.0





3.0





5.0





10.0







4.

Analyze
: How does the mutation rate affect the speed at which a population adapts to its
environment?

5.

Think and discuss
: You may have noticed that above a certain mutation rate the time required
for a population to adapt to

its background may increase. Why do you think this is so? If
possible, discuss your answer with your classmates and teacher.



6.

Apply
: Scientists doing artificial breeding experiments often use radiation or other methods to
increase the mutation rate. Why
is a high mutation rate useful?


7.

Investigate
: Use the Gizmo to develop a population of insects that are well adapted to their
environment. (
Average fitness
is above 90%.) Change the
mutation rate

to 0.1, and run the
simulation. Then, observe the population

with a
mutation rate

of 10.0.




What do you notice?




If a population is already well
-
adapted to its environment, will most mutations be helpful
or harmful? Explain. _____________________________________________





Appendix G: Teacher’s note

Graphic Organizer: Compare/Contrast Artificial and Natural Selection

In the Venn diagram below, explain the differences between artificial vs. natural selection and what

the two have in common.





















Differences and Similarities between

Artificial Selection and Natural Selection

They both require that there be genetic, heritable differences within the organisms of the population.


In both cases, something is leading to the greater reproductive fitness of some individuals over others
(In
the case of
natural selection
, it is the environment which causes differential reproduction, in the case
of artificial selection, it is the person doing the selection).


They both lead to changes in allele frequencies in the population over tim














A
ppendix H: Green Apple Red Appl
es

Apples
will be

pri
nted on green or red/pink paper

Green

= write down two concepts that resonated with you from today’s lesson

Red

= write down one thing that you did not understand or would like to know more of