GENERAL BIOLOGY

1. Descent
with
Modificatio
n
GENERAL BIOLOGY 2│Grade 11 STEM Nobility
Gigmoto Rural Development High School

2. Lesson Objective:
•Show patterns of descent
with modification from
common ancestors to
produce the organismal
diversity observed today.
(STEM_BIO11/12-IIIc-g-10)

3. Unscramble and Match Me!
• Listed below are jumbled letters.
Arrange the letters and match the
unscrambled word on the three
pictures shown on the right.
1. WCNARSEIDRLAH
2. EOTNRAUNELTALSIC
3. NLEOUTVLIO

4. Questions
1. Are you familiar with the pictures
from the activity?
2. Can anyone explain what the
pictures in the activity are trying to
say?
3. What do you think are the
relevance of the three pictures with
our lesson for today?

5. •Descent with Modification
•Heredity
•Genes
•Evolution
•Charles Darwin
•Natural Selection

6. What is Descent with Modification?
Descent with modification refers to the
passing on of traits from parent organisms
to their offspring. This passing on of traits
is known as heredity, and the basic unit of
heredity is the gene. Genes are the
blueprints for making an organism and, as
such, hold information about its every
conceivable aspect: its growth,
development, behavior, appearance,
physiology, and reproduction
(Klappenbach, 2019).

7. Evolution as ‘Descent with
Modification’
Evolution described as “descent
with modification” by Charles Darwin
refers to the species that changed over
time, giving rise to the new species and
share a common ancestor.
https://www.istockphoto.com/illustrations/human-
evolution

8. • Charles Darwin (1809–
1882)
was born in
western England. As a boy, he
had a consuminginterest
in nature.When
Darwin
was 16, his father sent him to the
University of Edinburgh to study
medicine, but he dropped out without a
degree and enrolled at Cambridge
University with the intent of
becoming a clergyman. At that time,
most naturalists and scientists
belonged to the clergy. After
graduation, Darwin joined the crew of
the survey ship HMS Beagle as ship
naturalist and conversation companion
to Captain Robert FitzRoy. FitzRoy chose
Darwin because of his education and
Who is Charles
Darwin?
https://www.britannica.com/biography/Charles-

9. Heredity and Evolution
According to Charles Darwin, all
species descended from only a
few life forms that had been
modified over time. This "descent
with modification," as he called
it, forms the backbone of his
Theory of Evolution, which posts
that
the development of new types of
of
organism
s
organism
s
from pre-existing
types over time
is how
certai
n
species
evolve. Evolution of Life stock illustration
https://www.istockphoto.com/vector/evolution-of-life-
gm472382319-35329094

10. Natural
Selection

11. Natural Selection
• Natural selection comes into play,
according to Darwin, when a species
adapts to its environment, thanks to its
specific genetic makeup. Say at some
point in time two species of wolves lived
in the Arctic: those with short, thin fur
and those with long, thick fur. Those
wolves (A) with long, thick fur was
genetically capable of living in the cold.
Those with (B) short, thin fur were not.
Therefore, those wolves whose
genetics allowed them to live
successfully in their environment lived
longer, bred more frequently, and passed
on their geneS. They were "naturally
selected" to thrive.
• Those wolves that were not genetically
Figure a: Copyright © Mike Dodd;
Figure b: Copyright © Chris Brunskill/Ardea

12. In an earlier study
conducted by the University
of California-Davis School
ofVeterinary Medicine
(UCDSVM) in 2011,it was
found that American and
European dogs have genes
originating from askals or
village dogs from the
Philippines,Taiwan, Brunei,
Indonesia, andThailand.
Ancient AskalsCould Be the Ancestors of Modern
Dogs,According to Study. MARIOALVAROLIMOS.
https://steemit.com/philippines/@darthnava/great-dog-breed-
aspin
Aspin or ‘Asong Pinoy’

13. Aspin dogs are bred from a variety of
mixed breeds that are roaming
the Philippine islands. This
breeding style makes the Aspin dog
healthier than most other breeds
because they are naturally bred.
This process leads to less health
issues and a more balanced
breed because it shares so many
different
Naturally, Aspin dogs are
all
the
sam
e
traits.
aroun
d
coats,
an
d
height, have
short
similar
features.
DogBreedInfo.co
m
King the Aspin dog at 10 months
old
from Bacolod City, Philippines
DogBreedInfo.com

14. We have here 3 activities
about Descent with
Modifications. Please
choose only 1 activity which
you think is convenient to
you. Follow
the instructions from the
activity you have chosen.

15. Direction: Write at least 3-5 sentences about the connection of
this picture on the evolutionary status of the organisms today.
Write it in your notebook or on a clean sheet of paper. (10pts)
Activity
A

16. Activity
B
Make acreative timeline of an example of ‘Descent with Modification’. The
timeline should include one organism as an example of how ‘Descent with
Modification’ can be explained. Make use of the materials readily available
from your house.Pleasebe guided by the rubrics below.
Documentatio
n of events
At least 3 events
are
presented with
clear
description.
6
Accuracy All the dates and
information in the
timeline are
correct and are
sequenced
accurately
2
Requirements Meet all the
requirement of
the timeline
2

17. Browse the web and make avideo presentation of an example of
‘Descent with Modification’. Make sure to include all the
developmental history of the sample organism you will present in
the video. Pleasebe guided by the video rubrics bel w.
Activity
C
Documentation
of events
The events
presented
are correct
with proper
description.
o 6
Accuracy All the events
included in
the video are
accurate.
2
Presentation The pieces of
information
were
presented in
an organized
manner.
2

18. COVID PRECAUTIONS!!!
Wash your hands with
a disinfecting soap
after touching objects
during your activity.
Wear
your
Maintain
a
PHYSICA
Bring
an
alcohol
Before going out; please be reminded
of the following:

19.  What isCharlesDarwin’s role in the
Descent with Modification and
Evolution?
 How was Darwin’s use of the phrase
‘Descent with Modification’ used to
describe the process of evolution?
•How does heredity and evolution
work?
Questions to Ponder

20. DIRECTIONS:
A. Complete the sentence by filling in the blanks with the correct
word/words from the word pool. Write the answer in your notebook.
1.According to , all species descended from only a few life forms that had
been modified over time.
2. refers to the species that changed over time, giving rise to the new
species and share a common ancestor.
3. are the blueprints for making an organism and, as such, hold information
about
its every conceivable aspect.
4.Darwin use the phrase instead of evolution.
5. occurs through interactions between individual organisms and
their environment, individuals do not evolve.
POST TEST

21. Search for a partner from your classmates.
Each of you should look around each of your
households. Search for organisms (animals/plants)
which you think is a product of ‘Descent with
Modification’. Identify the modifications you can
observe on the organism.
Exchange your ideas with your partner through
chat, videocall, or any way possible.
Note: if you are going to exchange ideas in person,
please remember to follow the safety protocols.
EXTEND

22. COVID PRECAUTIONS!!!
Wash your hands with
a disinfecting soap
after touching objects
during your activity.
Wear
your
Maintain
a
PHYSICA
Bring
an
alcohol
Before going out; please be reminded
of the following:

23. • AncientAskalsCould Be the Ancestors of Modern Dogs,According to
Study. MARIOALVAROLIMOS. May 10, 2020.
https://www.dogbreedinfo.com/a/aspin.htm
• Dog Breed Info:Aspin. https://www.esquiremag.ph/long-
reads/features/askals-ancestors-modern-dogs-a00293-20200510
• The Development of EvolutionaryThought. General Biology 2.Grade
11Self Learning Kit. Quarter 3Week4. Schools Division of Negros
Oriental.
• DEPEDMost Essential Learning Competencies
References: