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Essential Biology 5.4 Evolution
Student Name: Caitlin Barrett
Date:
Complete the self-assessment rubric before submitting.
You should complete the reader ‘Evolution and Darwin’ before this Essential Biology worksheet.
1.
Define evolution.
“Evolution is the cumulative change in the heritable characteristics of a population” (1 p. 37)
2.
Populations tend to produce more offspring than the environment can support.
Explain how the following lead to a ‘struggle for survival’
a.

Competition for food
Competition for food can lead to a struggle for survival because the strong will get first choice of food
and those who are weak have to eat the leftovers or find a different food source causing the weak to lack
food and eventually die.

Competition for mates
Competition for mates can lead to a struggle for survival because males will fight to show their strength to
females in many species and this could lead to death as well as some species such as lions will kill their
young if the other parent has found a new partner.

Competition for space
Competition for space can lead to a struggle for survival because if theres no space then organisms will
fight to the death for their space to be able to mate with their partner.

Parasitism
Parasitism can lead to a struggle for survival because survive at another organisms expense therefore the
organism it feeds off of has to struggle to survive and not get used as a feeding ground.

Disease
Disease can lead to a struggle for survival because some diseases can be contagious and therefore can
lead to epidemics killing out masses of species at once.

Predation
Predation can lead to a struggle for survival because it can cause population decreases when a predator
hunts its prey and the prey need to struggle to survive and get away.
b.
Explain the significance of variation within a species in relation to survival.
The significance of variation within a species in relation to survival is that if there is variation
natural selection occurs where those with the best traits are able to survive and reproduce where
the useless traits die off. The variation allows for the better traits to continue on and evolve into
stronger creatures based on mutations and mixing the best traits available.
Stephen Taylor
http://sciencevideos.wordpress.com
Bandung International School
Essential Biology 5.4 Evolution
Student Name: Caitlin Barrett
c.
Date:
Outline how the following aspects of sexual reproduction contribute to variation within a
species:
Meiosis
Two sets of DNA are contributed to form a mix of the two parents creating a random outcome that cannot
be duplicated.
Random fertilization
Allows for a mix of traits generally stronger traits that allow the species to get stronger and better at
survival. Mixing traits at random can create many different outcomes
Mutation
Random mutations occur in only some species and can allow the species to breed in new
and beneficial traits to make them better equipped to survive.
d.
State which of the above is the main source of variation within genes.
Meiosis is the main source of variation within genes.
e.
Explain the term descent with modification.
Descent with modification is an old term for evolution meaning that over time species evolve keeping the
better traits that allow them to survive.
f.
Describe how the struggle for survival lead to natural selection.
The struggle for survival leads to natural selection because the traits that allow the species to best survive
are carried on because they find mates easily and they are able to survive what those without the trait
cannot.
3.
Antibiotic resistance in bacteria is an example of evolution.
a. What is Staphylococcus aureus?
A bacteria that is found usually on the skin and mucous membranes that also causes pus-producing
infections, cellulitis and life- threatening sepsis.
b. Distinguish between MRSA and MSSA.
MRSA is methycillin-resistant and MSSA is methycillin-susceptible
c. Use the key terms environmental change, variation, survival, reproduction to annotate this
diagram, explaining how antibiotic resistance has evolved.
Original population: population before antibiotics where there was no resistance to antibiotics
Stephen Taylor
http://sciencevideos.wordpress.com
Bandung International School
Essential Biology 5.4 Evolution
Student Name: Caitlin Barrett
Date:
Source of variation: antibiotics were introduced to ward off antibiotics and certain strands
become resistant to antibiotics.
Environmental change: the restraint strain is able to reproduce while the other strands die off
causing the illness to continue
Effect on population: the illness continues to effect the population because of the resistant strands
that were not affected by the antibiotics.
Selection for: selected because they have the gene that is resistant to the antibiotic.
Inheritance:the resistant gene is carried on and the strand continues to grow and affect the
population until a new antibiotic is introduced.
''........can we doubt (remembering that many more
individuals are born than can possible survive) that
individuals having any advantage, however slight, over
others, would have the best chance of surviving and
procreating their kind? On the other hand, we may feel
sure that any variation in the least injurious would be
rigidly destroyed. This preservation of favourable
variations and the rejection of injurious variations, I call
Natural Selection' Darwin C. (1859) The Origin of
Species
4.
Explain one other example of evolution of
a species, in response to environmental
change.
(Galapagos finches or pepper moths)
Pepper moths evolved based on their environment because they needed to be able to camoflage with their
surroundings. A genetic mutation allowed for the trait to be spread and allow them to blend in with their
environment to avid predators. The moths with the trait of the “soot” covered wings that blend In with the
trees in their changed environment due to factors possibly like factories, were able to reproduce and pass
on this trait allowing the moths to survive and blend in to remain unseen to predators.
5. Research Another reliable source of evidence to support the theory of evolution by natural
selection is the fossil record—paleontologists have been uncovering fossilized remains of species
Stephen Taylor
http://sciencevideos.wordpress.com
Bandung International School
Essential Biology 5.4 Evolution
Student Name: Caitlin Barrett
Date:
from sedimentary rock deposits and using this information to create timelines of changes in the
earth and development of species.
a. Outline formation of sedimentary rock.
The formation of sedimentary rock begins with igneous, metamorphic or sedimentary rock that are
exposed at the earths surface. They are subject to weathering (breaking into smaller pieces), deposition
(settling out of the air or water), erosion (similar to weathering), lithification (sediments become rock)
and compaction (weight squeezing particles together). This process takes millions of years and then
begins again to form more rock.
b. Describe how the position of a fossil in sedimentary rock give a clue to its position in
time.
A fossil in sedimentary rock can give a clue to its time based on the layers of rock before and after it
showing around what time period it would have been formed.
c. State some other methods used to confirm the age of fossils.
You can use radio-active dating, fission-track dating, paleomagnetism or amino-acid dating. All these use
certain chemicals or materials that give clues to the age of the fossil.
6.
Homologous structures
a. Define homologous
Homologous structures are similar body structures that have adapted to be used for different functions
such as pig and horse legs, there are similar structures but different uses.
b. One of the most obvious examples of homologous structures in animals is the pentadactyl
limb.
Define pentadactyl.
Penta means five and dactyl is the arrangement of fingers and toes, therefore pentadactyl is having five
digits on a limb.
c. Homologous structures has evolved through ‘adaptive radiation’. Explain this term.
source: http://en.wikipedia.org/wiki/File:Evolution_pl.png
Adaptive radiation is the formation of new species following the availability of new environments where
they need to adapt to the changes of the new environment.
Stephen Taylor
http://sciencevideos.wordpress.com
Bandung International School
Essential Biology 5.4 Evolution
Student Name: Caitlin Barrett
7.
Date:
Selective breeding of domesticated animals
a. State the purpose of selective breeding
Selective breeding is used to get particular traits to create the “desired” genetic abilities.
b. Describe why selective breeding is also known as artificial selection.
Selective breeding is also known as artificial selection because the choices are made not because of
survival needs but instead because of desired traits that are made by outer sources and not the organism
itself.
Artificial selection, like natural selection, can work in two ways. State examples of each:
c. Selection for : if a dog displays a trait that is beneficial to the breeder, such as
intelligence, it will be allowed to reproduce and carry on the trait
d. Selection against : if a dog develops a trait that is not beneficial such as arthritis in a
racing dog, it will not be allowed to reproduce and carry on the trait.
ToK AoK: “It’s only a theory.” Explain, using the scientific method, why evolution is described as a
theory and why this represents a high level of certainty in science. What is the linguistic confusion that
leads some non-scientists to question the validity of evolution as scientific truth?
Stephen Taylor
http://sciencevideos.wordpress.com
Bandung International School
Essential Biology 5.4 Evolution
Student Name: Caitlin Barrett
Date:
Theory is the highest level of certainty in science and since scientists were not present during the different
stages of evolution they used empirical evidence to support their theory. Some scientists question
evolution as scientific truth because it is evidence based but only to a certain extent as there are still tests
continuing on to further our knowledge on how evolution occurred.
Works Cited
1. Allott, Andrew. IB Study Guide: Biology for the IB Diploma. s.l. : Oxford University Press, 2007.
978-0199151431.
Self
Assessment:
Essential Biology
Criterion
Complete (2)
Partially complete (1)
NA
File names sensible, work complete and wellpresented. Sentences are complete and include
vocabulary. All command terms highlighted or
underlined.
Presentation &
Organisation
Stephen Taylor
http://sciencevideos.wordpress.com
Bandung International School
Assessment
Self
Teacher
Essential Biology 5.4 Evolution
Student Name: Caitlin Barrett
Date:
Academic
Honesty
Objective 1
understanding
Sources cited using mla method, with Works
Cited section complete and correct.
NA
All answers for the following command terms
Most answers for the following command terms
correct:
correct:
Define
Draw
Label
List
Measure State
All answers for the following command terms
Most answers for the following command
correct:
terms correct:
Objective 2
understanding Annotate
Apply
Calculate
Describe
All answers for the following command terms
correct:
Distinguish Estimate Identify
Outline
Most answers for the following command
terms correct:
Objective3
understanding Analyse Comment Compare Construct Deduce Derive Design Determine Discuss
Evaluate
Logic, notation,
mathematical
working
Further research
Explain Predict
Show
Solve
Sketch Suggest
NA
Answers are presented in a logical and concise
manner. SI units used most times, with correct
unit symbols and definitions of terms. All
mathematical working shown.
NA
Evidence is apparent of research and reading
beyond the textbook and presentations to find
correct answers to challenging questions. If any
questions are unanswered, this criterion scores
zero.
Total (max 10):
Stephen Taylor
http://sciencevideos.wordpress.com
Bandung International School