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Department of Education – Division of Palawan

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Science – Grade 10
Contextualized Self-Learning Module
Quarter 3 – Module 5: Evidence for Evolution
First Edition, 2021

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Arnaldo G. Ventura

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Introductory Message
This Self-Learning Module (SLM) is prepared so that you, our dear learners, can
continue your studies and learn while at home. Activities, questions, directions,
exercises, and discussions are carefully stated for you to understand each
lesson.

Each SLM is composed of different parts. Each part shall guide you step-by-
step as you discover and understand the lesson prepared for you.

Pre-tests are provided to measure your prior knowledge on lessons in each SLM.
This will tell you if you need to proceed on completing this module or if you
need to ask your facilitator or your teacher’s assistance for better
understanding of the lesson. At the end of each module, you need to answer
the post-test to self-check your learning. Answer keys are provided for each
activity and test. We trust that you will be honest in using these.

In addition to the material in the main text, Notes to the Teacher are also
provided to our facilitators and parents for strategies and reminders on how
they can best help you on your home-based learning.

Please use this module with care. Do not put unnecessary marks on any part
of this SLM. Use a separate sheet of paper in answering the exercises and tests.
And read the instructions carefully before performing each task

If you have any questions in using this SLM or any difficulty in answering the
tasks in this module, do not hesitate to consult your teacher or facilitator.

Thank you.

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 Science 10
Third Quarter Evidence for Evolution
Week 5

MELC : Explain how fossil records, comparative anatomy, and

genetic information provide evidence for evolution.
Week 5 S10LT-IIIf-39

Objective/s : 1. Explain how fossil records, comparative anatomy, and

genetic information provide evidence for evolution;
2. Distinguish homologous structure from analogous structure;
and
3. Give importance of understanding the origin of life.

What I Know

Let us find out how much you already know about this module. After
taking and checking this short test, take note of the items that you were not
able to answer correctly and look for the right answer as you go through this
module.

Directions: Read and understand the following sentences carefully. Choose

the letter of the best answer. Write your answer on a separate sheet of paper.

1. Which of the following statements describes evolution in biology?

a. Fossils or old things that are preserved.
b. Living things constantly change.
c. Life begins in sea.
d. Plants were the first organisms that existed.

2. Which of the following is CORRECT about analogous structure?

a. Structurally similar c. structurally and functionally
similar
b. Functionally similar d. normally nonfunctional

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3. Homologous organs or structures have
_________________________________.
a. same origin but different functions
b. different origin but same functions
c. same origin and same functions
d. different origin and different functions

4. The author of the famous book on evolution, On the Origin of Species.

a. Charles Darwin
b. Jean Baptiste de Lamarck
c. Aristotle
d. Von Baer

5. Which of the following statements shows analogous organs?

a. Tubers of potato and sweet potato.
b. Tubers of Dahlia and sweet potato.
c. Tubers of potato and roots of rose.
d. All the above

6. Which of the following pieces of evolution evidence contain both

homologous and analogous structure?
a. Fossil record
b. Genetic information
c. Comparative anatomy
d. Molecular biology

7. Some organisms that share common ancestor have features that have
different functions, but similar features. These are known as
_____________.
a. Vestigial structures
b. Homologous structures
c. Analogous structures
d. Fossil structures

8. Two organisms that are closely related would have

____________________.
a. Similar DNA sequence
b. Exactly the same DNA sequence
c. No protein in common
d. Completely different DNA sequence

9. Scientists compare DNA from living organisms to identify

___________________________.
a. Natural selection
b. A fossil’s location
c. Similarities between species
d. Geographic isolation

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 10. Fossil records provide evidence of ____________________.
a. Evolution
b. Population
c. Photosynthesis
d. None of these

What is It

You know that some organisms are no longer existing today. you may
be curious why some of the animals that are present before are no longer
existing today. This extinction was instigated by various phenomenon,
environmental factors, and human activities.

By learning through this module, you will have an idea how fossil records,
comparative anatomy, and genetic information provide evidence for
evolution. Likewise, it is anticipated that you will give value to the origin of life,
make sure to protect the living things and its environment to ensure the survival
and conservation of species.

Activity 1. What comes First?

Directions: Arrange the following significant events in geologic time. Put

numbers 1-12, 1 as the first event and 12 as the last event. Write your answer
on a separate sheet of paper.

_____1. Planet Earth formed.

_____2. The Earth’s first oceans formed.
_____3. Oxygen began to accumulate in the Earth’s atmosphere.
_____4. The first animals with backbones (fish) evolved.
_____5. The dinosaurs went extinct.
_____6. Earth’s core and crust formed.
_____7. The first life appeared on Earth.
_____8. The first animals appeared.
_____9. The first land plants appeared.
_____10. The first dinosaurs appeared.

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_____11. The first land animals with backbones evolved.
_____12. Modern human appeared.

Truly, there is so much in the Earth’s Geologic Time. Good job! You were
able to identify significant events in the origin of Earth and its organisms.

Activity 2. Fill in and Draw in!

Directions: Fill in the data table to show how long in millions of years each Era
has lasted. Choose your answer on the box provided. Afterwards, create a pie
chart to show the percentage of time each Era of Geologic time.

66 mya 185 mya

291 mya 4058 mya

The Divisions of Geologic Time Percent Millions of Years Ago

The Age of the Earth 100% 4600 mya

Cenozoic Era 1.5 % 1. ____________
Mesozoic Era 4% 2. ____________
Paleozoic Era 6.5% 3. ____________
Precambrian Time 88% 4. ____________

Based on the data presented in the table above, create a pie chart to
show the percentage of time in each Era of Geologic time.

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 As you have answered the previous activities, you have learned about
the significant events that happened in the geologic time. Why is it important
for you to learn this? How is this related to evolution? Why is it vital to understand
the evolution and the evidence? All these questions will be answered as we
go through this lesson. Hoping that you can grasp all the needed skills, values,
and concepts after this module. Have fun and enjoy learning!

Let us get started.

Evolution

An alteration or change in the characteristics of a species over several

generations and relies on the process of natural selection (Your Genome,
2017).

Evolution is a scientific theory that explains how life changes through

time.
Biological evolution accounts for the variety or diversity of species developed
through slow processes over many generations. These includes of evidence
from geology, fossils, comparative anatomy and analyzing genetic
information provide the bases for the theory of evolution (MBUSD Org 2009).

Theories

The theory of evolution by natural selection, first formulated in Charles

Darwin's book "On the Origin of Species" in 1859, is the process by which
organisms change over time as a result of changes in heritable physical or
behavioral traits. Changes that allow an organism to better adapt to its
environment will help it survive and have more offspring. Evolution by natural
selection is one of the best substantiated theories in the history of science,
supported by evidence from a wide variety of scientific disciplines, including
paleontology, geology, genetics, and developmental biology (Than, K 2018).

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Sources of Evidence for Evolution

A. Evidence from Fossil Records

Much of the evidence

for evolution comes from
studying fossils. These are
remnant or trace of an
organism from the past, such
as a skeleton or leaf imprint,
embedded and preserved in
Earth’s crust (MBUSD Org 2009).
Fossils are a great help to
scientist since it serves as
document the existence of
now-extinct species, showing
that different organisms have
lived on Earth during different Image credit: Adapted from Khan Academy
periods of the planet's history. and "Equine evolution," by H. Zell, CC BY-SA 3.0.
They can also help scientists reconstruct the evolutionary histories of
present-day species (Khan Academy, n.d). Example: The Horse lineage as
the best-studied fossil.
Using these fossils, scientists have been able to reconstruct and track
a large, branching "family tree" for horses and their now-extinct relatives.
Changes in the lineage leading to modern-day horses, such as the
reduction of toed feet to hooves, may reflect adaptation to changes in the
environment (Khan Academy, n.d.). This is just one of the examples that
shows that fossils provide a historical sequence of life and shows the
existence of now extinct organisms.

Although scientists have collected thousands of fossils, there are

many gaps in the fossil record. That is because most ancient species did not
fossilize. They simply decayed and were lost from the fossil record. Scientists
estimate that only a small percentage of past organisms have been (or will
be) found as fossils.

B. Hint of Evolution from Comparative Anatomy

Comparative anatomy is the study of the similarities and differences

in the structures of different species. Similar body parts may be homologies
or analogies. Both provide evidence for evolution (FlexBooks, 2018).

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 Homologous structures have a common origin, but do not necessarily
perform the same function (MBUSD Org 2009). If two or more species share
a unique physical feature, such as a complex bone structure or a body
plan, they may all have inherited this feature from a common ancestor. This
is physical features shared due to evolutionary history (Khan Academy,
n.d.).

Image credit: Adapted from Khan Academy and "Understanding evolution:

Figure 7," by OpenStax College, Biology, CC BY 4.0.

The image above, a classic example, the forelimbs of whales,

humans, birds, and dogs look different on the outside this was a result of
adaption to function in different environments. Still, it shows similarities in
structure. If you look at the bone structure of the forelimbs, you will find that
the pattern of bones is very similar across species (Khan Academy, n.d.).

Analogous structures serve the same function but come from

different origins (MBUSD Org 2009). The structures are similar because they
evolved to do the same job, not because they were inherited from a
common ancestor. For example, the wings of bats and birds, shown in
Figure below, look similar on the outside. They also have the same function.
However, wings evolved independently in the two groups of animals. This is
apparent when you compare the pattern of bones inside the wings
(FlexBooks, 2018).

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 Bat

Bird

Image credit: "Comparative Anatomy: Figure 3 " by

FlexBooks® 2.0, CK-12 Biology For High School

C. Evidence from Genetic Information

All species of organisms have DNA as their hereditary material.

Scientists compare the DNA base sequences of different species to
determine evolutionary relationships. Species that share more similarities in
their DNA base sequences are more closely related than those that share
fewer similarities. Scientists hypothesize that if two species have similarities in
their base sequences, they share a common ancestor (MBUSD Org 2009).
Through molecular biology it shows how DNA and the genetic code reflect
the shared ancestry of life. DNA comparisons can show how related species
are (Khan Academy, n.d.).

The basic idea behind this is that two species have the "same" gene”
because they inherited it from a common ancestor. For instance, humans,
cows, chickens, and chimpanzees all have a gene that encodes the
hormone insulin, because this gene was already present in their last
common ancestor.

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 What I Can Do

Activity 3. Examine Me!

Directions: Examine the images given below. These are skeletal structure of the
front limbs of 6 animals: human, crocodile, whale, cat, bird, and bat. Look at it
closer. Take note of the similarities and differences. Afterwards, take note what
is being ask in the given table below the images. Write your answer on a
separate paper.

Human Crocodile Bird Whale Cat Bat

For each animal, indicate what type of movement each limb is responsible
for.

Table 1. Animal’s font limbs and its primary functions

Animal Primary Functions

Human Using tools, picking up and holding objects
Whale 1.
Crocodile 2.

Cat 3.
Bird 4.
Bat 5.

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 Compare the skeletal structure of each limb to the human arm. Relate the
differences you see in form the differences in function.

Table 2. Comparison of Human Arm Form and its Function to other Animals

Comparison to Comparison to
Animal
Human Arm in Form Human Arm in Function

Whale has a much shorter and The whale fin needs to be longer
thicker humerus, radius, and to help in movement through
Whale ulna. Much longer metacarpals. water. Thumbs are not
Thumb has been shortened to a necessary as the fins are not
stub. used for grasping

1. ___________________________ 2. ___________________________
_______________________________ _______________________________
_______________________________ _______________________________
_______________________________ _______________________________
Crocodile
_______________________________ _______________________________
_______________________________ _______________________________
_______________________________ _______________________________

3. ___________________________ 4. ___________________________
_______________________________ _______________________________
_______________________________ _______________________________
_______________________________ _______________________________
Cat
_______________________________ _______________________________
_______________________________ _______________________________
_______________________________ _______________________________

5. ___________________________ 6. ___________________________
_______________________________ _______________________________
_______________________________ _______________________________
_______________________________ _______________________________
Bird
_______________________________ _______________________________
_______________________________ _______________________________
_______________________________ _______________________________

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 7. ___________________________ 8. ___________________________
_______________________________ _______________________________
_______________________________ _______________________________
_______________________________ _______________________________
Bat
_______________________________ _______________________________
_______________________________ _______________________________
_______________________________ _______________________________

Activity 4. Where do I Belong?

Directions: Read and analyze the following situations below. Categorize each
if it tells about homologous or analogous structure. Write HS if the situation and
structure belong to homologous and AS if they are analogous. Afterwards,
answer the follow up question given in each situation.
Situation A.
A duck and a platypus are similar in that they both lay eggs.

1. Is egg laying in these two organisms an example of a Homologous or

Analogous trait?
______________________________________________________
2. Are ducks and platypuses closely related?
_____________________________

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Situation B.
Humans, Chimpanzees, and Gorillas all have similar hand structures.

1. Are the hands in these organisms examples of Homologous or Analogous

structures?
____________________________________________________________
2. Are humans, chimps, and gorillas closely related?
________________________

Situation C
Monarch and Blue Morpho Butterflies have similar wings.

1. Are the wings of these two organisms an example of Homologous or

Analogous structures?
_________________________________________________
2. Are monarchs and morphos closely related?
___________________________

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Situation D
The wings of a bat and the wings of a butterfly are similar in that they
both allow the organisms to fly.

1. Are the wings on these two organisms Homologous or Analogous

Structures? ____________________________________
2. Are bats and butterflies closely related? ___________________

What’s More

Activity 5. May I Know Your Thoughts?

Directions: Now that you have learned about the evidence for evolution, it is
time to share your thoughts about the quotation below. How important is it to
understand the origin of life? Relate your understanding to the given quotation
below. Write your thoughts on the space provided.

“It is not the strongest of the species that survives, nor the most
intelligent that survives. It is the one that is most adaptable to change.”
- Charles Darwin

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_______________________________________________________________________
_______________________________________________________________________
_______________________________________________________________________
_______________________________________________________________________
_______________________________________________________________________
_______________________________________________________________________
_______________________________________________________________________
_____________________________________________.

Activity 6. What evidence is this?

Directions: Identify what sources of evidence for evolution are following

concepts. Write FR if it tells about fossils, CA if it is comparative anatomy and
GI if it is about genetic information. Do this on a separate sheet of paper.
______1. The fossilized leaf found on sedimentary rocks that once part of
vascular plant during Carboniferous Period.
______2. Dinosaur bone that found in on Earth’s crust.
______3. The forelimbs of whales, humans, birds, and dogs look different on the
outside but shows similarities in structure.
______4. Animals such as penguins and fish both have fin-like structures to help
them navigate through their aquatic environments.
______5. Humans, cows, chickens, and chimpanzees all have a gene that
encodes the hormone insulin.

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 What I Have Learned
Think deeply and share us your thoughts about everything you have
learned in this lesson.
Activity 7. Fill Me

Directions: Complete the illustration below by filling the empty bucket. Write
the salient points you have learned in this lesson.

___________________________________________
___________________________________________
___________________________________________
___________________________________________
___________________________________________
___________________________________________
___________________________________________
___________________________________________
___________________________________________
__________________________________________

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 Assessment

Multiple Choice

Directions: Choose the letter of the best answer. Write the chosen letter on a
separate sheet of paper.

1. Which of the following is the strongest evidence for change over a long
period of time?
a. DNA c. embryo studies
b. Fossils d. direct observation of living species

2. Any variation that can help an organism survive in its environment is

called ________.
a. Adaptation c. characteristics
b. Competition d. vestigial structure

3. When an eagle’s wing and an ostrich’s wing are compared, similar

structures are discovered. They are ____________.
a. Homologous structure
b. Cast fossils
c. Analogous structure
d. Naturally selected

4. Which would be considered homologous structures?

a. A specific protein in yeast also found in rhesus monkeys.
b. Bones in a bird’s arm and bones in a frog’s arm
c. A permineralized bone of wooly mammoth and original material of
a wooly mammoth
d. The wing of a bat and the wing of an insect

5. Which of the following would best determine whether two plant species
share a recent common ancestor?
a. DNA sequence
b. Habitat distribution
c. Stem lengths
d. Flowering times

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6. How do fossils support evolution?
a. Individual species disappear and reappear in the fossil record over
time.
b. The fossil record provides evidence that all organisms developed at
the same time.
c. Organism in the fossil records are identical to living organisms.
d. The fossil record provides evidence that organism have changed
over time.

7. Through careful observation, Charles Darwin came to understand that:

a. Populations of plants and animals in nature most often consist of
individuals that are clones of each other.
b. Those individuals whose variation gives them an advantage in
staying alive long enough to reproduce are more likely to pass their
traits on the next generation,
c. Populations of a species that become isolated from others by
adapting to different environmental riches quickly become extinct.
d. All of the above

8. Which of the following is evidence of a common ancestor?

a. Fossil record
b. Comparative anatomy
c. Genetic information
d. All of the above

9. During the 1800’s and 1900’s a lot changed in evolutionary theory. Which
of the following was first theory to be generally accepted by the
academic community?
a. Mutations occur during DNA replication.
b. The Earth and species change over time.
c. Genes code for proteins.
d. Uniformitarianism.

10. Charles Darwin was best known in the 19th century for:
a. Creating the idea of evolution
b. Formulating the idea of uniformitarianism
c. Making the idea of evolution acceptance for scientists and the
educated general public
d. All of the above

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What I Know Activity 2
18 Assessment
1. B 1. 66 mya 1. A
2. B 2. 185 mya 2. A
3. A 3. 291 mya 3. A
4. A 4. 4058 mya 4. B
5. A 5. A
6. C 6. D
7. B 7. B
8. A 8. D
9. C 9. B
10. A 10. C
What is It
Activity 1
1. 1
2. 3
3. 5 Activity 3 - Learners’ answer may vary.
4. 7
5. 11 Activity 4
6. 2
7. 4 A.
8. 6 1. AS
9. 8 2. No, one is a bird, and one is a mammal.
10. 10 B.
11. 9 1. HS
12. 12 2. Yes, both are mammals.
C.
1. HS
2. Yes, both are insects.
D.
1. AS
2. No – Bats are mammals, butterflies are insects.
Activity 5- Learners’ answer may vary.
Activity 6
1. FR
2. FR
3. CA
4. CA
5. GI
Activity 7- Learners’ answer may vary.
Answer Key
References

Khan Academy. “About Evidence for Evolution.” Accessed April 07, 2021.
https://www.khanacademy.org/science/biology/her/evolution-
and-natural-selection/a/lines-of-evidence

MBUSD Org. “About Evolution Evidence.” Accessed April 07, 2021.

http://www2.mbusd.org/staff/pware/PDFPPT/EvolutionEvidence.
pdf

FlexBooks, “About Comparative Anatomy.” Accessed April 07, 2021.

https://flexbooks.ck12.org/cbook/ck-12-biology-flexbook-
2.0/section/5.16/primary/lesson/living-species-bio

Your Genome. “About what is evolution.” Accessed April 07, 2021.

https://www.yourgenome.org/facts/what-is-evolution

Ker Than, "What is Darwin's Theory of Evolution?," Live Science,

Accessed April 07, 2021. https://www.livescience.com/474-
controversy-evolution-works.html

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