EVOLUTION
Earth and Life Science
MODULE 13
Second Quarter
Let’s Recall
Directions. Identify the body system based on the
functions stated below:
FUNCTION
1. It facilitates movement and locomotion.
2. It uses hormones to maintain homeostasis.
3. It protects body parts and stores minerals.
4. It maintains the pH of the blood and facilitates the exchange of gases.
5. It defends the body against pathogens and diseases.
6. It controls sensory and motor functions.
7. It transports blood from the heart to the lungs.
8. It breaks down food into molecules the cell can use.
9. It protects the body from the external environment
10. It removes metabolic wastes and retains the proper amounts of water, salts,
and nutrients inside the body.
BODY SYSTEM
Let’s Elaborate
TELL THE STORY BEHIND THE PICTURE
JEAN BAPTISTE LAMARCK:
1. Tendency toward perfection
Ex. Ancestors of birds acquired the urge
to fly, birds kept trying to fly, so their
wings increased in size and became
more suited for flying
2. Use and Disuse
Ex. Due to frequent use, birds
eventually transformed their limbs
to wings.
Due to disuse, the wings will
decrease in size and finally
disappear.
3. Inheritance of Acquired Traits
Ex. Short-neck giraffes acquired longer
necks then pass on this trait to their
offspring.
If you spent your life lifting weights,
your children will inherit big muscles too.
Let’s Elaborate
TELL THE STORY BEHIND THE PICTURE
CHARLES DARWIN:
1.The struggle for existence
- members of each species compete to
obtain food, shelter etc.
- Thomas Malthus believes that babies
are being born faster than people dying
- Population grow faster than resources
2. Survival of the fittest
- ability to survive and reproduce in its
specific environment (fitness)
- inherited characteristic that increases
an organism’s chance of survival
(adaptation)
3. Natural Selection
- takes place without human control
- results in changes in the inherited
characteristics of a population
4. Descent with modification
- species today look different from their
ancestors
- living things have a common ancestor
(common descent)
TELL THE STORY BEHIND THE PICTURE
Evolution
• is described as the change in species over time.
• It is also the change in allelic frequency of the
population of species.
• occurs when inherited changes from generation to
generation within one population of a species give
rise to a new appearance, a new genetic code, and
ultimately, a new species.
A Species is a group of organisms that
share similar characteristics and can
interbreed with one another to produce
fertile offspring.
TELL THE STORY BEHIND THE PICTURE
Evolution in the population is brought about by
different agents. These are genetic drift, gene flow,
mutations, non random mating, and natural selection.
Genetic drift is the change in the gene pool of a
population due to chance. There is unpredictable
fluctuation in the frequency of alleles from one
generation to another. Examples of genetic drift are
the bottleneck effect and the founder effect.
The bottleneck effect occurs when there
is a great reduction in the size of
populations due to environmental factors
such as fires, earthquakes, and floods.
The founder effect happens when a small
population of organisms breaks away from
the larger group to colonize a new area.
Let’s Elaborate
Gene flow is defined as the movement of alleles into
or out of the population. It occurs when there is a
migration of fertile individuals between populations.
This tends to increase the genetic diversity in the
populations.
A mutation occurs when there is a change in the
genetic makeup, during the DNA replication
caused by radiation or other environmental
stressors.
Let’s Elaborate
Non random mating increases the frequency of
animals with desirable traits. It causes evolution
because it intrudes the natural pool of gene variations.
Natural selection explains the difference in
survival of the individual and reproduction in a
particular environment.
Let’s Elaborate
EVIDENCE OF EVOLUTION
FOSSIL RECORDS
HOMOLOGOUS
STRUCTURES
ANALOGOUS
STRUCTURES
Fossils provide solid evidence that organisms from the past
are not the same as those found today.
The similar construction of appendages of a human, a dog, a
bird, and a whale indicates that they share a common
ancestor.
The similarities in function of organisms’ body parts because
of adaptation to similar environments.
COMPARATIVE
EMBRYOLOGY
Example: the wings of a bird and a bat do not imply possible
descent from common ancestors
The human appendix, the tail bone, and wisdom tooth are
called vestige structures because they have no apparent
function at all and are said to be residual parts from a past
common ancestor.
Similarities on the embryonic stage of organisms prove
probable common ancestors.
COMPARATIVE
BIOCHEMISTRY
Example: all vertebrate embryos go through a stage wherein
they all have gill pouches at the sides of their throats. Later,
the gills develop into different structures. In fishes, it
developed as gills, whereas in mammals it develops into a
Eustachian tube of the ears.
The more closely related the organisms are, the more similar
their biological pathways.
VESTIGIAL
STRUCTURES
MOLECULAR BIOLOGY
BIOGEOGRAPHY
Example: Humans, mice, and rabbits are all mammals. They
share almost the same biochemistry. This is the reason why
mice and rabbits are used to test new medicines for future
human use.
Comparison of the genetic sequences of organisms has
revealed that genetically close organisms have a high degree
of similarities in their DNA sequence. Molecular biology
attempts to explain the evolution at molecular and cellular
levels. It looks closely at the role of mutations in genes in
the evolution of life on earth.
The distribution of similar fossils of animals and even the
geographic distribution of other existing organisms in
different continents confirm this theory. The koalas, pandas,
tarsiers, and kangaroos are found only in specific locations.
Let’s Elaborate
FOSSIL RECORDS
HOMOLOGOUS
STRUCTURES
ANALOGOUS
STRUCTURES
Fossils provide solid evidence that organisms from the past
are not the same as those found today.
The similar construction of appendages of a human, a dog, a
bird, and a whale indicates that they share a common
ancestor.
The similarities in function of organisms’ body parts because
of adaptation to similar environments.
COMPARATIVE
EMBRYOLOGY
Example: the wings of a bird and a bat do not imply possible
descent from common ancestors
The human appendix, the tail bone, and wisdom tooth are
called vestige structures because they have no apparent
function at all and are said to be residual parts from a past
common ancestor.
Similarities on the embryonic stage of organisms prove
probable common ancestors.
COMPARATIVE
BIOCHEMISTRY
Example: all vertebrate embryos go through a stage wherein
they all have gill pouches at the sides of their throats. Later,
the gills develop into different structures. In fishes, it
developed as gills, whereas in mammals it develops into a
Eustachian tube of the ears.
The more closely related the organisms are, the more similar
their biological pathways.
VESTIGIAL
STRUCTURES
MOLECULAR BIOLOGY
BIOGEOGRAPHY
Example: Humans, mice, and rabbits are all mammals. They
share almost the same biochemistry. This is the reason why
mice and rabbits are used to test new medicines for future
human use.
Comparison of the genetic sequences of organisms has
revealed that genetically close organisms have a high degree
of similarities in their DNA sequence. Molecular biology
attempts to explain the evolution at molecular and cellular
levels. It looks closely at the role of mutations in genes in
the evolution of life on earth.
HOMOLOGOUS
ANALOGOUS
Similar structure
Different structure
Different function
Similar Functions
Common ancestor
Not from common
ancestor
The distribution of similar fossils of animals and even the
geographic distribution of other existing organisms in
different continents confirm this theory. The koalas, pandas,
tarsiers, and kangaroos are found only in specific locations.
Let’s Elaborate
FOSSIL RECORDS
HOMOLOGOUS
STRUCTURES
ANALOGOUS
STRUCTURES
Fossils provide solid evidence that organisms from the past
are not the same as those found today.
The similar construction of appendages of a human, a dog, a
bird, and a whale indicates that they share a common
ancestor.
The similarities in function of organisms’ body parts because
of adaptation to similar environments.
COMPARATIVE
EMBRYOLOGY
Example: the wings of a bird and a bat do not imply possible
descent from common ancestors
The human appendix, the tail bone, and wisdom tooth are
called vestige structures because they have no apparent
function at all and are said to be residual parts from a past
common ancestor.
Similarities on the embryonic stage of organisms prove
probable common ancestors.
COMPARATIVE
BIOCHEMISTRY
Example: all vertebrate embryos go through a stage wherein
they all have gill pouches at the sides of their throats. Later,
the gills develop into different structures. In fishes, it
developed as gills, whereas in mammals it develops into a
Eustachian tube of the ears.
The more closely related the organisms are, the more similar
their biological pathways.
VESTIGIAL
STRUCTURES
MOLECULAR BIOLOGY
BIOGEOGRAPHY
Example: Humans, mice, and rabbits are all mammals. They
share almost the same biochemistry. This is the reason why
mice and rabbits are used to test new medicines for future
human use.
Comparison of the genetic sequences of organisms has
revealed that genetically close organisms have a high degree
of similarities in their DNA sequence. Molecular biology
attempts to explain the evolution at molecular and cellular
levels. It looks closely at the role of mutations in genes in
the evolution of life on earth.
The distribution of similar fossils of animals and even the
geographic distribution of other existing organisms in
different continents confirm this theory. The koalas, pandas,
tarsiers, and kangaroos are found only in specific locations.
Let’s Elaborate
FOSSIL RECORDS
HOMOLOGOUS
STRUCTURES
ANALOGOUS
STRUCTURES
Fossils provide solid evidence that organisms from the past
are not the same as those found today.
The similar construction of appendages of a human, a dog, a
bird, and a whale indicates that they share a common
ancestor.
The similarities in function of organisms’ body parts because
of adaptation to similar environments.
COMPARATIVE
EMBRYOLOGY
Example: the wings of a bird and a bat do not imply possible
descent from common ancestors
The human appendix, the tail bone, and wisdom tooth are
called vestige structures because they have no apparent
function at all and are said to be residual parts from a past
common ancestor.
Similarities on the embryonic stage of organisms prove
probable common ancestors.
COMPARATIVE
BIOCHEMISTRY
Example: all vertebrate embryos go through a stage wherein
they all have gill pouches at the sides of their throats. Later,
the gills develop into different structures. In fishes, it
developed as gills, whereas in mammals it develops into a
Eustachian tube of the ears.
The more closely related the organisms are, the more similar
their biological pathways.
VESTIGIAL
STRUCTURES
MOLECULAR BIOLOGY
BIOGEOGRAPHY
Example: Humans, mice, and rabbits are all mammals. They
share almost the same biochemistry. This is the reason why
mice and rabbits are used to test new medicines for future
human use.
Comparison of the genetic sequences of organisms has
revealed that genetically close organisms have a high degree
of similarities in their DNA sequence. Molecular biology
attempts to explain the evolution at molecular and cellular
levels. It looks closely at the role of mutations in genes in
the evolution of life on earth.
The distribution of similar fossils of animals and even the
geographic distribution of other existing organisms in
different continents confirm this theory. The koalas, pandas,
tarsiers, and kangaroos are found only in specific locations.
Let’s Elaborate
COMPARATIVE
BIOCHEMISTRY
MOLECULAR
BIOLOGY
The more closely related the organisms are,
the more similar their biological pathways.
FOSSIL RECORDS
Fossils provide solid evidence that organisms from the past
Comparison of the genetic sequences of
organisms has revealed that genetically close
organisms have a high degree of similarities
in their DNA sequence. Molecular biology
attempts to explain the evolution at molecular and
cellular levels.
It looks closely at the role of
mutations in genes in the evolution of life on
earth.
are not the same as those found today.
Example: Humans, mice, andHOMOLOGOUS
rabbits are
all
The similar construction of appendages of a human, a dog, a
STRUCTURES
and a whale indicates that they share a common
mammals. They share almost
the bird,
same
ancestor.
ANALOGOUS
similarities in function of organisms’ body parts because
biochemistry. This is the reason
why miceThe
and
STRUCTURES
of adaptation to similar environments.
BIOGEOGRAPHY The distribution of similar fossils of animals
rabbits are used to test new medicines for Example:
future
the wings of a bird and a bat do not imply possible
and even the geographic distribution of other
descent from common ancestors
human use.
VESTIGIAL
The human appendix, the tail bone, and wisdom tooth are
existing organisms in different continents confirm
STRUCTURES
called vestige structures because they have no apparent
function at all and are said to be residual parts from a past
this theory. The koalas, pandas, tarsiers, and
common ancestor.
COMPARATIVE
Similarities on the embryonic stage of organisms prove
kangaroos are found only in specific locations.
EMBRYOLOGY
probable common ancestors.
COMPARATIVE
BIOCHEMISTRY
MOLECULAR BIOLOGY
BIOGEOGRAPHY
Example: all vertebrate embryos go through a stage wherein
they all have gill pouches at the sides of their throats. Later,
the gills develop into different structures. In fishes, it
developed as gills, whereas in mammals it develops into a
Eustachian tube of the ears.
The more closely related the organisms are, the more similar
their biological pathways.
Example: Humans, mice, and rabbits are all mammals. They
share almost the same biochemistry. This is the reason why
mice and rabbits are used to test new medicines for future
human use.
Comparison of the genetic sequences of organisms has
revealed that genetically close organisms have a high degree
of similarities in their DNA sequence. Molecular biology
attempts to explain the evolution at molecular and cellular
levels. It looks closely at the role of mutations in genes in
the evolution of life on earth.
The distribution of similar fossils of animals and even the
geographic distribution of other existing organisms in
different continents confirm this theory. The koalas, pandas,
tarsiers, and kangaroos are found only in specific locations.
Let’s Elaborate
FOSSIL RECORDS
HOMOLOGOUS
STRUCTURES
Fossils provide solid evidence that organisms
RECORDS
provide solid evidence that organisms from the past
from the past are not the FOSSIL
same
asFossils
those
are not the same as those found today.
HOMOLOGOUS
The similar construction of appendages of a human, a dog, a
found today.
STRUCTURES
bird, and a whale indicates that they share a common
ANALOGOUS
STRUCTURES
ancestor.
The similarities in function of organisms’ body parts because
of adaptation to similar environments.
COMPARATIVE
The similar construction of appendages
of a
Example: the wings of a bird and
a bat do not imply possible
BIOCHEMISTRY
descent from common ancestors
human, a dog, a bird, and aVESTIGIAL
whale indicates
The human appendix, the tail bone, and wisdom tooth are
STRUCTURES
vestige structures because they have no apparent
that they share a common ancestor. called
function at all and are said to be residual parts from a past
COMPARATIVE
EMBRYOLOGY
ANALOGOUS
STRUCTURES
COMPARATIVE
EMBRYOLOGY
common ancestor.
Similarities on the embryonic stage of organisms prove
probable common ancestors.
Example: all vertebrate embryos go through a stage wherein
The similarities in function of organisms’
body
they all have gill pouches at the sides of their throats. Later,
the gills develop into different structures. In fishes, it
parts because of adaptation to developed
similar
as gills, whereas in mammals it develops into a
Eustachian tube of the ears.
MOLECULAR
COMPARATIVE
The more closely related the organisms are, the more similar
environments.
BIOCHEMISTRY
their biological pathways.
BIOLOGY
Example: the wings of a bird and a bat do not
imply possible descent from common
MOLECULAR BIOLOGY
ancestors
VESTIGIAL
STRUCTURES
Example: Humans, mice, and rabbits are all mammals. They
share almost the same biochemistry. This is the reason why
mice and rabbits are used to test new medicines for future
human use.
Comparison of the genetic sequences of organisms has
revealed that genetically close organisms have a high degree
of similarities in their DNA sequence. Molecular biology
attempts to explain the evolution at molecular and cellular
levels. It looks closely at the role of mutations in genes in
the evolution of life on earth.
The human appendix, the tail bone, and
BIOGEOGRAPHY
The distribution of similar fossils of animals and even the
BIOGEOGRAPHY
wisdom tooth are called vestige
structures
geographic distribution of other existing organisms in
different continents confirm this theory. The koalas, pandas,
because they have no apparent function
atandall
tarsiers,
kangaroos are found only in specific locations.
and are said to be residual parts from a past
common ancestor.
Similarities on the embryonic stage of organisms
prove probable common ancestors.
Example: all vertebrate embryos go through a
stage wherein they all have gill pouches at the
sides of their throats. Later, the gills develop into
different structures. In fishes, it developed as
gills, whereas in mammals it develops into a
Eustachian tube of the ears.
The more closely related the organisms are, the
more similar their biological pathways.
Example: Humans, mice, and rabbits are all
mammals. They share almost the same
biochemistry. This is the reason why mice and
rabbits are used to test new medicines for future
human use.
Comparison of the genetic sequences of
organisms has revealed that genetically close
organisms have a high degree of similarities in
their DNA sequence. Molecular biology attempts
to explain the evolution at molecular and cellular
levels. It looks closely at the role of mutations in
genes in the evolution of life on earth.
The distribution of similar fossils of animals and
even the geographic distribution of other existing
organisms in different continents confirm this
theory. The koalas, pandas, tarsiers, and
kangaroos are found only in specific locations.
Let’s Dig In
Activity 1: “Proof of Evidence”
Directions. Match the picture with each type of
evidence. Choose your answer from the word bank
below. (6 points)
A. ANALOGOUS STRUCTURE
B. HOMOLOGOUS STRUCTURE
C. EMBRYOLOGY
D. FOSSIL RECORDS
.
E. VESTIGIAL STRUCTURES
F. MOLECULAR EVIDENCE
Let’s Dig In
Activity 2: “Label Me”
Directions. Label the parts of the rooted phylogenetic
tree based on the given description below. (5 points)
ROOT
indicates that an ancestral lineage gave
rise to all organisms on the tree
BRANCH
POINT
indicates where two lineages diverge
BASAL
TAXON
a lineage that evolved early from the root
and remains unbranched
SISTER
TAXA
two lineages that stem from the same
branch point
POLYTOMY a branch with more than two lineages
Let’s Dig In
Activity 3: “Identify Me”
Directions. Analyze the phylogenetic tree. Fill in the
blanks with the correct answer. (5 points)
1. The root of the tree is represented
by the letter ____.
2. _____ shows a common ancestor of
B and C.
3. F represents the ______________.
4. B and C are __________________.
5. Which is more likely closely related,
A and C or C and D? __________
Let’s Evaluate
Directions: Read and analyze each item carefully. Choose the letter
of the correct answer.
1. Which of the following refers to the process in nature where organisms
better adapted to their environment tend to survive and reproduce more than
those less adapted to the environment?
A. genetic drift
C. natural selection
B. mutation
D. random mating
2. What do we call the change in the gene pool of a small population that
takes place strictly by chance?
A. genetic drift
C. mutation
B.genetic frequency
D. random selection
3. Which of the following may be caused by environmental disasters leading
to the death or extinction of organisms?
A. bottleneck effect
C. gene flow
B. Founder effect
D. genetic drift
4. Who proposed that organisms could acquire characteristics during their
lifetime that they could pass down to their offspring?
A. Carolus Linnaeus
C. Jean Baptiste de Lamarck
B. Charles Darwin
D. Thomas Malthus
5. Which of the following occurs when there’s a change in the genetic makeup
due to DNA replication, radiation, or other environmental stressors?
A. genetic drift
C. genetic variation
B.gene flow
D. mutation
6. Who devised a system for identifying, naming, and classifying organisms?
A. Alfred Russel Wallace
C. Jean Baptiste de Lamarck
B. Carolus Linnaeus
D. Thomas Malthus
7. Who asserted that populations could grow faster than their resources?
A. Alfred Russel Wallace
C. Jean Baptiste de Lamarck
B. Carolus Linnaeus
D. Thomas Malthus
8. Which of the following occurs when there is a great reduction in the
size of populations due to environmental factors such as fires,
earthquakes, and floods?
A. bottleneck effect
C. gene flow
B. founder effect
D. genetic drift
9. What do we call the process that results in changes in the genetic
content of a population over time?
A. evolution
C. migration
B. gradualism
D. mutation
10. What do we call the diagram that traces evolutionary relationships
and connections among organisms?
A. evolution
C. lineages tree
B. family tree
D. phylogenetic tree
For numbers 11-15, write TRUE if the statement is correct. Write FALSE
if it is not.
11. Homologous structures are structures with similar functions.
12. Fossils are the only record that can prove that evolution
occurred.
13. Evolution on Earth is a continuous process. It is still happening
and will continue to occur.
14. Nonrandom selection of mates in animals cause variety of traits
in their offspring.
15. The founder effect occurs when a small population of organisms
breaks away from the larger group to colonize a new area.
WHAT IS YOUR
KEY TAKEAWAY
TODAY?
Let’s Dig In
Activity 1: “Proof of Evidence”
Directions. Match the picture with each type of
evidence. Choose your answer from the word bank
below. (6 points)
A
B
A. ANALOGOUS STRUCTURE
B. HOMOLOGOUS STRUCTURE
C. EMBRYOLOGY
C
E
D
F
D. FOSSIL RECORDS
.
E. VESTIGIAL STRUCTURES
F. MOLECULAR EVIDENCE
Let’s Dig In
Activity 2: “Label Me”
Directions. Label the parts of the rooted phylogenetic
tree based on the given description below. (5 points)
SISTER
TAXA
ROOT
indicates that an ancestral lineage gave
rise to all organisms on the tree
BRANCH
POINT
indicates where two lineages diverge
BASAL
TAXON
a lineage that evolved early from the root
and remains unbranched
SISTER
TAXA
two lineages that stem from the same
branch point
POLYTOMY
POLYTOMY a branch with more than two lineages
BASAL
TAXON
ROOT
BRANCH POINT
Let’s Dig In
Activity 3: “Identify Me”
Directions. Analyze the phylogenetic tree. Fill in the
blanks with the correct answer. (5 points)
1. The root of the tree is represented
K
by the letter ____.
G
2. _____
shows a common ancestor of
B and C.
BASAL TAXON
3. F represents the ______________.
SISTER TAXA
4. B and C are __________________.
5. Which is more likely closely related,
A and C
A and C or C and D? __________
Let’s Evaluate
Directions: Read and analyze each item carefully. Choose the letter
of the correct answer.
1. Which of the following refers to the process in nature where organisms
better adapted to their environment tend to survive and reproduce more than
those less adapted to the environment?
A. genetic drift
C. natural selection
C
B. mutation
D. random mating
2. What do we call the change in the gene pool of a small population that
takes place strictly by chance?
A. genetic drift
C. mutation
A
B.genetic frequency
D. random selection
3. Which of the following may be caused by environmental disasters leading
to the death or extinction of organisms?
A. bottleneck effect
C. gene flow
A
B. Founder effect
D. genetic drift
4. Who proposed that organisms could acquire characteristics during their
lifetime that they could pass down to their offspring?
A. Carolus Linnaeus
C. Jean Baptiste de Lamarck
C
B. Charles Darwin
D. Thomas Malthus
5. Which of the following occurs when there’s a change in the genetic makeup
due to DNA replication, radiation, or other environmental stressors?
A. genetic drift
C. genetic variation
D
B.gene flow
D. mutation
6. Who devised a system for identifying, naming, and classifying organisms?
A. Alfred Russel Wallace
C. Jean Baptiste de Lamarck
B
B. Carolus Linnaeus
D. Thomas Malthus
7. Who asserted that populations could grow faster than their resources?
A. Alfred Russel Wallace
C. Jean Baptiste de Lamarck
D
B. Carolus Linnaeus
D. Thomas Malthus
8. Which of the following occurs when there is a great reduction in the
size of populations due to environmental factors such as fires,
earthquakes, and floods?
A. bottleneck effect
C. gene flow
A
B. founder effect
D. genetic drift
9. What do we call the process that results in changes in the genetic
content of a population over time?
A. evolution
C. migration
A
B. gradualism
D. mutation
10. What do we call the diagram that traces evolutionary relationships
and connections among organisms?
A. evolution
C. lineages tree
D
B. family tree
D. phylogenetic tree
For numbers 11-15, write TRUE if the statement is correct. Write FALSE
if it is not.
FALSE
11. Homologous structures are structures with similar functions.
12. Fossils are the only record that can prove that evolution
occurred. FALSE
13. Evolution on Earth is a continuous process. It is still happening
TRUE
and will continue to occur.
14. Nonrandom selection of mates in animals cause variety of traits
in their offspring. TRUE
15. The founder effect occurs when a small population of organisms
breaks away from the larger group to colonize a new area.
TRUE