The document discusses the classification of organisms and the binomial system of nomenclature. It explains that all organisms are classified based on their characteristics and relationships. Each organism is assigned a genus and species name, with the genus indicating the broader group it belongs to. Classification sorts organisms into a hierarchy of taxonomic ranks including species, genus, family, order, class, phylum, and kingdom. The example of chimpanzees and their taxonomic classification is provided to illustrate this system.

1. PAGE
UMUC Asia DE lab – Evolution
© UMUC – all rights reserved.Name:
Lab 8. Evolution
Introduction
Evolution is often defined as change over time, usually in
response to a change in the environment. What this means is
that the gene pool of a population shifts as time passes.
What is a gene pool? It is simply the collection of all the
available alleles of all the genes on all the chromosomes in the
population. What's a population? It is the group of individuals
that have geographic and behavioral mating access to each
other. Geographic access is obvious; the dandelions in a yard in
Virginia are not in the same gene pool as those in a yard in
Pennsylvania, even if they are the same species. They could
mate if they were brought together, but dandelion pollen doesn't
blow that far, so they are geographically isolated. Behavioral
mating access can be less obvious; one example would be a stag
that keeps all other males out of his territory and mates with all
the does. The other stags are not allowed to mate, so their genes
are not in the pool.
A great deal of the time for most species, evolution is not
occurring. The gene pool stays the same, because the
environmental situation is not changing. In the early days of
population genetics, people argued over whether dominant
alleles could "take over" a gene pool without any selection. Two
mathematicians, Hardy and Weinberg, showed that this would
not happen.

2. The basis of their argument is that the gene pool will not
change, and the frequency of the various alleles will stay the
same if the following conditions are met:
· The population is large.
· The population is freely interbreeding at random (this
excludes the stag and the does).
· No individuals are taking their alleles out of the population
(emigrating) or adding their alleles to the population
(immigrating), so the percentages of the alleles can't change
because of migration.
· There are no mutations, so no new alleles appear.
· None of the alleles has a selective advantage (in other words,
there aren't any combinations of alleles that give some
individuals a better chance of surviving that anyone else).
Here is the mathematical basis of their argument:
Imagine a simple situation in which a gene has only two alleles,
A and a, and A is dominant. Let the frequency of A, expressed
as a decimal with a value less than one, be p, and let the
frequency of a, expressed as a decimal with a value less than
one, be q. Because there are only two alleles, every allele must
be either A or a, so,
p + q = 1
By definition, p and q are also the frequencies of the alleles in
the eggs and sperm produced by this species. These sperm and
eggs can come together in four ways when random mating
occurs.

3. 1. The chance that a male p sperm will meet a female p egg is p
x p, or p2. The children produced by this cross will be
genetically AA and express the dominant allele; they will have
the A phenotype.
2. The chance that a male p sperm will meet a female q egg is p
x q, or pq. The children produced by this cross will be
genetically Aa and express the dominant allele; they will also
have the A phenotype.
3. The chance that a male q sperm will meet a female p egg is
alsop x q, or pq. The children produced by this cross will also
be genetically Aa and express the dominant allele; they will
also have the A phenotype.
4. The chance that a male q sperm will meet a female q egg is q
x q, or q2. The children produced by this cross will be
genetically aa and express the recessive allele; they will have
the a phenotype.
These four situations are the only possibilities, so
p2 + pq + pq + q2 = 1 (1.0 represents 100% of all possible
events in a mating)
When we combine the middle two terms, we get
p2 + 2pq + q2 = 1
These two formulas,
p + q = 1
p2 + 2pq + q2 = 1
summarize what is known as the Hardy-Weinberg Law.
However, usually we don't know the frequency of the alleles in

4. a population; in most cases, we can't even see the gametes! If
we want to know what the frequencies of the alleles are, we
have to use these two formulas to figure it out.
The most important things to remember are the two formulas
above. In these formulas,
· p = the frequency of the dominant allele
· q = the frequency of the recessive allele
· p2 = the frequency of individuals in the population who are
homozygous dominant
· 2pq = the frequency of individuals in the population who are
heterozygous
· q2 = the frequency of individuals in the population who are
homozygous recessive
Materials
· Three colours of beans (chili, pinto and navy are good, but any
three contrasting objects will do – M&Ms, coins, beads, etc).
· Two bowls
· A pocket calculator (MS Windows has one too)
Procedure
Two alleles which control hair texture are incompletely
dominant to each other, and the phenotypic expression of hair
texture is a function of which alleles are present. The
genotypes and phenotypes are:
Genotype
Phenotype
C1C1
curly

5. C1C2
wavy
C2C2
straight
This is where Hardy-Weinberg comes in. Recall:
p2 + 2pq + q2 = 1.0
Remember:
p2 = the frequency of the C1C1s
2pq = the frequency of the C1C2s
q2 = the frequency of the C2C2s
These percentages will remain stable through all subsequent
rounds of mating of this population.
Please refer to the following table for calculation references.
Also, please adjust the calculations for the rest of the tables.
Please submit this Lab Report Sheet in Webtycho in the
Assignments folder.
Data Sheet - Sample table and calculations:
Student answers to questions
1. In the absence of selection, what happens to gene
frequencies in a population?
Type your answer here. This textbox expands as you type.
2. What have you learned about population genetics so far?

6. i.e., what do these results tell you about how genes in a gene
pool behave under tightly controlled (i.e.,
artificial/hypothetical) circumstances?
Type your answer here. This textbox expands as you type.
<more below>
You'll use your three colours of beans (or any 3 objects of your
choice), from this point on, to represent the individuals in your
population. The red (chili) beans represent the homozygous
dominants (C1C1 - curlies), the mottled (pinto) beans the
heterozygotes (C1C2 - wavies), and the white (navy) beans the
homozygous recessives (C2C2 - straights).
Pick the beans (objects) two at a time and record your results
here. Use the example above (page 6) to help you in your
calculations).
Experiment 1
In this first exercise, you are going to determine what happens
when you allow your population of 80 to interbreed freely.
In a bowl, place the correct numbers of the three colours of
beans to represent the population of 80 people. For 20 C1C1s,
40 C1C2‘s, and 20 C2C2’s, you would choose 20 red beans, 40
pinto beans, and 20 white beans (or any three different objects
you chose). Mix them thoroughly and then, without peeking
(i.e., at random), withdraw two beans (or two objects). Record
the genotypes represented by the two beans.
Example: if you withdraw a white bean and a pinto bean the
first time, then you will record one (1) C2C2 x C1C2; you have
mated one pair.

7. Put your first two beans in the second bowl and continue to
draw pairs of beans from the first bowl until you have
withdrawn all 40 pairs. Your records will now show a series of
80 random matings from this population.
There are six possible combinations:
1. C1C1 x C1C1 (two chili beans),
2. C1C1 x C1C2 (one chili, one pinto),
3. C1C1 x C2C2 (one chili, one navy),
4. C1C2 x C1C2 (two pintos),
5. C1C2 x C2C2 (one pinto, one navy), and
6. C2C2 x C2C2 (two navies).
Record the total number for each of the six matings.
Data sheet (fill in the BLUE and YELLOW areas).
(see page 6 for detailed calculation help).
MATINGS
OFFSPRING = Matings x 4
C1S
C2S
C1C1
X
C1C1
C1C1
X

8. C1C2
C1C1
X
C2C2
C1C2
X
C1C2
C1C2
X
C2C2
C2C2
X
C2C2

9. total
P=
Frequency of C1 =
Q=
Frequency of C2 =
3. How do these compare with the parental generation?
Type your answer here. This textbox expands as you type.
4. What principle have you demonstrated with this exercise?
Type your answer here. This textbox expands as you type.
<scroll down for more>
Experiment 2
Put your beans back in the bowl. This time, withdraw only 20
pairs (= 20 random matings), and record the results as you did
in Task 1.

10. Next, calculate the offspring of this generation: again, assume
4 offspring per mating. Total the numbers of C1C1s, C1C2s
and C2C2s. and then calculate the allele frequencies. Finally,
determine the genotypic frequencies.
Data sheet (fill in the BLUE and YELLOW areas).
(see page 6 for detailed calculation help).
MATINGS
OFFSPRING = Matings x 4
C1S
C2S
C1C1
X
C1C1
C1C1
X
C1C2
C1C1

11. X
C2C2
C1C2
X
C1C2
C1C2
X
C2C2
C2C2
X
C2C2

12. total
P=
Frequency of C1 =
Q=
Frequency of C2 =
5. How do these last P and Q (frequencies) compare with the
P (parental) generation (Experiment 1)?
Type your answer here. This textbox expands as you type.
6. If you repeated this experiment (i.e., you selected another
20 pairs from the bowl) would you expect to get the same
result? Why or why not?
Type your answer here. This textbox expands as you type.
7. What principle have you illustrated this time?
Type your answer here. This textbox expands as you type.
<scroll down for more>
Experiment 3

13. Now you are going to assume that your population has been
invaded by an ET which is a human predator. It particularly
fancies people with curly hair - eats them preferentially - and
when it moves on (looking for more of its favourite lunch), your
population has been denuded of curlies (C1C1).
Set up your new population in the bowl, and go through the
mating (bean picking/ withdrawal) procedure again, recording
your results. Again, assume that each mating produces four
offspring.
(see page 6 for detailed calculation help).
MATINGS
OFFSPRING = Matings x 4
C1S
C2S
C1C2
X
C1C2
C1C2
X
C2C2

14. C2C2
X
C2C2
total
P=
Frequency of C1 =
Q=
Frequency of C2 =
8. What is going on?
Type your answer here. This textbox expands as you type.
9. How have the relative proportions of C1s and C2s changed?
Type your answer here. This textbox expands as you type.

15. 10. What principle have you demonstrated here?
Type your answer here. This textbox expands as you type.
<scroll down for more>
Experiment 4
Go back to your population in Experiment 3. This time, assume
that through some further natural disaster which has
discriminated against people with wavy hair, half the wavies
have also been lost. Allow this population to breed at random
and determine the outcome of the next generation.
(see page 6 for detailed calculation help).
MATINGS
OFFSPRING = Matings x 4
C1S
C2S
C1C2
X
C1C2
C1C2

16. X
C2C2
C2C2
X
C2C2
total
P=
Frequency of C1 =
Q=
Frequency of C2 =
13. What is going on this time?
Type your answer here. This textbox expands as you type.
14. What if this trend continues?

17. Type your answer here. This textbox expands as you type.
SUMMARY
15. Summarize what you have learned from this lab about the
principles of evolution.
Type your answer here. This textbox expands as you type.
Define (one short sentence each):
1) Evolution
2) Microevolution
3) Macroevolution
4) Genetic Drift
5) Natural selection
What did you learn about or in each of the following?
a) The Hardy-Weinberg Equilibrium
b) Experiment 1
c) Experiment 2
d) Experiment 3
e) Experiment 4

18. PAGE
Page 2 of 15
Biol 102 © UMUC. All rights reserved.
Classification labBiol 102, UMUC
Classification lab
Overview
Taxonomy is the study of the classification of organisms.
Classification is simply a way of sorting things in an orderly
manner. For example, if you have a box of mixed stationary
supplies on your desk—paper clips, staples, rubber bands, and
thumb tacks—and you decide to put them into four separate
containers so that you can use them more efficiently, you are
classifying them.
There are at least two million species of organisms alive on the
planet right now, most of them insects. There have been many
other species that are now extinct. To try to keep them in some
kind of order to examine, compare, and discuss them in a
consistent manner, biologists have set up a system known as the
binomial system of nomenclature. In this system, two names are
assigned to each organism, a genus name and a species name.
The genus name indicates the group of related species to which
the organism belongs, and the species name indicates the
specific species.
For example, the scientific name for a chimpanzee is Pan
troglodytes. Pan is the genus name, and troglodytes is the
species name. By convention, both words are written in italics
or underlined. Note that the more general term comes first. If
the American president Abraham Lincoln had been a species all
by himself, his name would have been Lincoln abraham.
Starr (2000, glossary) defines a species as "one kind of

19. organism." Among sexually reproducing organisms, a species is
a group of naturally interbreeding organisms that form a
genetically distinctive population reproductively isolated from
all others. Your textbook provides greater detail on the
technical definition of a species.
A group of closely related species forms a genus. The plural of
genus is genera. Genera are grouped into families, families into
orders, orders into classes, classes into phyla (the single is
phylum), and phyla into kingdoms. These levels are grouped
based on their common characteristics. Your textbook discusses
some of these defining characteristics in some detail.
The value of this system is that it not only gives each species a
name, but that it also puts it in a series of categories that
indicate its relationship to other similar species and also to
more distantly related ones.
Let's go back to the chimpanzee. Pan troglodytes belongs to the
family Pongidae, which includes the gorillas and the
orangutans. They all have distinctive molar teeth; flexible arm
and shoulder joints; arms longer than legs; and large complex
brains. None of them have a tail. The Pongidae belong to the
order Primata, which includes, in addition to the Pongidae, all
the monkeys and the prosimians, such as lemurs. All of these
animals are grouped together because they share a large group
of behavioral and anatomical characteristics. These include
excellent manual dexterity, a well-developed sense of sight, a
dependence upon learned behavior, a long infant-dependency
period, a complex social organization, prehensile hands with
opposable thumbs, mobile arms, binocular vision, and a reduced
snout.
The primates belong to the class Mammalia, which are animals
with hair or fur, high and controlled body temperature, glands
that produce milk, and complex teeth. The mammals belong to

20. the phylum Chordata, all of which have, at some stage in their
development, a dorsal stiffening rod (notochord) as the chief
internal support, a tubular nerve cord above the notochord, gill
slits leading into the anterior part of the digestive tract, and a
post-anal tail. In a chimpanzee, most of these disappear during
embryonic development, but they are all there at some stage.
Finally, the chordates belong to the kingdom Animalia. All
animals are multicellular heterotrophs that usually ingest food
and digest it in an internal cavity. Their cells lack the rigid cell
walls that characterize plant cells. Most animals are capable of
complex and relatively rapid movement and most reproduce
sexually.
As you can see, a taxonomic system goes from very specific
characteristics to very general ones. This information can be
used to create a dichotomous classification key, which is very
simply a system for identifying organisms in the field. At each
step, you are given two choices for a given characteristic; these
lead you to further choices more specifically identifying the
species until you finally have its name (or if you're really lucky,
a discovery of a new species).
Lab Activities
A. Using a Dichotomous Key
Lab Materials
Materials in your lab kit:
· none needed
Being able to use a dichotomous key is a very useful skill.
Many field guides, particularly ones that help you to identify
plants, are based on this principle. In this activity, you will use
a classification key to determine the names of nine species of
fish. To do so, you begin with the first pair of choices on the

21. key, working your way downward until you've successfully
identified the fish.
1. Review the following definitions and key to get a feel for
what you will be looking for in identifying the fish.
Definitions
the backbone side of the fish
e side of the fish nearer the tail
Simple Classification Key for Some Pacific Fishes
Choice
Characteristic
Next Move or Identification
1a
Fish has 5 or 6 gill openings on each side of the pharynx
2
1b
Fish has only one covered gill opening on each side of its
pharynx
3
2a
Very large, stout bodied; caudal fin is crescent shaped and
nearly symmetrical
White shark
2b

22. Large, slender bodied; dorsal lobe of caudal fin is much longer
than the ventral lobe
Blue shark
3a
One eye on each side of the head
4
3b
Both eyes on one side of the head
Flathead sole
4a
Pectoral fins and pelvic fins present
5
4b
Pectoral and pelvic fins absent
Moray eel
5a
One dorsal fin
6
5b
More than one dorsal fin
7
6a
Long winglike pectoral fin
California flying fish
6b
Small pectoral fin low on side
8
7a
2 dorsal fins
Great sculpin
7b
3 dorsal fins
Pacific cod
8a
Large black oval spots over all of upper body and caudal fin
Pink salmon

23. 8b
Fine specks on back, but no black spots
Chum salmon
2. Using the key above, identify the following fish and type the
name of each fish next to its letter: (type your answers in the
BOXES below each fish):
A
B
C
D
E
F
G
H
I
(Fish drawings copyright by Houghton Mifflin and Eschmeyer
& Herald)

24. References
Eschmeyer, W. N., and E. S. Herald. (1983). The Peterson field
guide series: A field guide to Pacific coast fishes—North
America. New York: Houghton Mifflin. (Plates 2, 6, 8, 11, 12,
16, 45)
Gendron, Robert P., Ph.D. (2000). "Classification and
evolution." Indiana University of Pennsylvania Biology
Department. Retrieved April 18, 2002, from
http://nsm1.nsm.iup.edu/rgendron/camin.htmlx.
Starr, Cecie. (2000). Basic concepts in biology. 4th ed.
Stamford: Thompson.
B. Taxonomic Classification
Materials in your lab kit:
· none
Additional materials you will need:
· scissors (optional)
(The following exercise was modified from one designed by
Robert P. Gendron, Ph.D., of Indiana University of
Pennsylvania. His permission to use it is gratefully
acknowledged.)
In order to design a dichotomous key for a group of related
organisms, you must first examine your specimens and
determine their specific characteristics. Then you must use
these characteristics to categorize them into larger and larger
groups such as genera, families, orders, and classes. In the
overview for this lab, you were given the description of the

25. classification of the chimpanzee as an example. For this
exercise, you are going to design a dichotomous key to sort
fourteen living species of caminalcules, which are imaginary
animals invented by the evolutionary biologist, Joseph Camin.
These animals are pictured below:
Living Caminalcules
(Caminalcule pictures copyright by Systematic Biology and
Robert R. Sokal.)
Supersize me version (
Print this out and cut out each one to help you rearrange and re-
examine them.
Each caminalcule has a number designation as its common
name. You may consider these drawings to be life size. Examine
the pictures and note the variety of appendages, shell shape,
color pattern, size, and any other details that you notice. You
may find it easier to do this if you print the page, cut out the
creatures, and move them around on your physical desktop.
Now create a hierarchical classification of these species, using
the format in the table below. Instead of using letters (A, B,
etc.), as in this example, use the number of each caminalcule
species. Keep in mind that the classification scheme below is
just a hypothetical example. Your classification may look quite
different from this one.
Sample Classification Scheme
Phylum Caminalcula
Class 1
Class 2

26. Order 1
Order 2
Order 3
Family 1
Family 2
Family 3
Family 3
Genus 1
Genus 2
Genus 3
Genus 4
Genus 5
Genus 6
A
G
H
D
B
J
L
E
K
C
F
I
1. The first step in this exercise is to decide which species
belong in the same genus. Species within the same genus share
characteristics not found in any other genera. The caminalcules
numbered 19 and 20 are a good example; they are clearly more
similar to each other than either is to any of the other living
species here, so we would put them together in their own genus.
Use the same procedure to combine the genera into families.
Again, the different genera within a family should be more
similar to each other than they are to genera in other families.
Families can then be combined into orders, orders into classes
and so on. Depending on how you organize the species, you may

27. only get up to the level of order or class. You do not necessarily
have to get up to the level of kingdom or phylum.
One of your problems will be convergent evolution; this is a
real problem faced by taxonomists every day. Look up
convergent evolution in your textbook or some other reference
to learn the meaning of the term.
2. Define this term in your own words and explain why it may
cause you problems in this exercise. (Here is a hint: claws have
arisen independently in caminalcules more than once during
evolution.)
Type in here – this expands as you type.
Definition: Convergent evolution + why it may cause problems
in taxonomy
3. Enter your classification scheme here. It does not have to be
as elegant as the sample scheme above, but it does have to be
clear. If you are uncertain how best to input your classification
scheme, contact your instructor.
Type in here – this expands as you type. <note: to insert a table,
use the menu item as shown: (you may click and drag to give
you more rows/columns)>
Classification Scheme:
4. Use your classification scheme to design a dichotomous key
that will account for the fourteen species. Remember that in
each step you can only have two choices. One problem you may
have is that your steps will have numbers and so do your
species. To keep things clear, refer to the names of the species
by using the number with the # symbol in front of it. In other
words, the fourteen species names will be #1, #2, #3, #4, #9,
#12, #13, #14, #16, #19, #20, #22, #24, and #26.

28. a. Enter your dichotomous key here. If you are uncertain how
best to input your dichotomous key, contact your instructor.
Note: Table headings are as follows (see pp 3-4):
Choice
Characteristic
Next Move or Identification
Type in here – this expands as you type. <note: to insert a table,
use the menu item as shown: (you may click and drag to give
you more rows/columns)>
References
Eschmeyer, W. N., and E. S. Herald. (1983). The Peterson field
guide series: A field guide to Pacific coast fishes—North
America. New York: Houghton Mifflin. (Plates 2, 6, 8, 11, 12,
16, 45)
Gendron, Robert P., Ph.D. (2000). "Classification and
evolution." Indiana University of Pennsylvania Biology
Department. Retrieved April 18, 2002, from
http://nsm1.nsm.iup.edu/rgendron/camin.htmlx.
Starr, Cecie. (2000). Basic concepts in biology. 4th ed.
Stamford: Thompson.
<end of file>
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