History of Life on Earth 0.2
by CHED on June 14, 2017
lesson duration of 1 minutes
under General Biology 2
generated on June 14, 2017 at 10:34 pm
Tags: History of Life on Earth
CHED.GOV.PH
K-12 Teacher's Resource Community
Generated: Jun 15,2017 06:34 AM
History of Life on Earth 0.2
( 1 hour and 1 min )
Written By: CHED on July 18, 2016
Subjects: General Biology 2
Tags: History of Life on Earth
Resources
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Content Standard
Relevance, Mechanisms, Evidence/Bases, and Theories of Evolution
Performance Standard
n/a
Learning Competencies
Describe general features of the history of life on Earth, including generally accepted dates and sequence of the
geologic time scale and characteristics of major groups of organisms present during these time periods
Introduction 5 mins
Communicating Learning Objectives
The lesson for today will cover the following topics:
1. Major events in the Geologic Time Scale (GTS)
2. Cambrian Explosion
Teacher Tip: This lesson will present formally the lesson on GTS. The learners will understand better the
highlights of each time frame in the GTS.
Motivation 5 mins
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Discussion: How Old is the Earth?
Discussion: How Old is the Earth?
Ask the following questions:
1. How old is the Earth?
2. What is the biggest time frame in the GTS?
3. What is the smallest time frame in the GTS?
Instruction 20 mins
Lecture of the Geologic Time Scale
1. Present a lecture discussion on the Geologic Time Scale
2. The following outline can guide the teacher in the discussion:
I. The Geological Time Scale (GTS)
A. Four eras - Precambrian; Paleozoic; Mesozoic; Cenozoic
B. Periods under the Paleozoic era -Cambrian,
-Cambrian, Ordovician, Silurian, Devonian, Carboniferous, Permian
C. Periods under the Mesozoic era - Triassic, Jurassic, Cretaceous
D. Periods under the Cenozoic era - Tertiary and Quaternary
II. Age in millions of years of each time period
III. Major events in the history of life
Teacher
Geologic
Time
Record
a tabular
representation
of the
major
divisions
of the
Earth’s
Teacher
Tip:Tip:
TheThe
Geologic
Time
Record
is aistabular
representation
of the
major
divisions
of the
Earth’s
history.
intervals
divided
described
longest
to the
shortest
as EONS,
ERAS,
history.
The The
timetime
intervals
are are
divided
and and
described
fromfrom
the the
longest
to the
shortest
as EONS,
ERAS,
PERIODS
EPOCHS.
period
an approximated
frame
characterized
by distinctive
PERIODS
and and
EPOCHS.
EachEach
period
has has
an approximated
timetime
frame
and and
characterized
by distinctive
features (events and organisms)
TheGeologic
Geologictime
timeisisdivided
dividedinto
intofour
fourlarge
largesegments
segmentscalled
calledEons:
Eons:Hadean,
Hadean,Archean,
Archean,Proterozoic
Proterozoicand
andPhanerozoic.
Phanerozoic.
The
ThePhanerozoic
Phanerozoicisisdivided
dividedinto
intoEras:
Eras:Paleozoic,
Paleozoic,Mesozoic,
Mesozoic,and
andCenozoic.
Cenozoic.Extinction
Extinctionevents
eventsand
andappearance
appearanceofofnew
new
The
lifeforms
formscharacterized
characterizedthe
thedivisions
divisionsamong
amongEras.
Eras.Smaller
Smallerdivisions,
divisions,called
calledPeriods,
Periods,characterized
characterizedby
byaasingle
singletype
typeof
of
life
rock
system,
make
each
Era.
Some
Periods
further
divided
intosmaller
smallertime
timeframe
framecalled
calledEpochs.
Epochs.(From:
(From:
rock
system,
make
upup
each
Era.
Some
Periods
areare
further
divided
into
http://goo.gl/ITmoty)
There is a mnemonics (memory device) to remember the Periods in exact order (from the earliest to the recent); jumps
between periods and epochs
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The teacher can also discuss CAMBRIAN EXPLOSION.
CAMBRIAN EXPLOSION is the belief that there was a sudden, apparent explosion of diversity in life forms about 545
millionyears
yearsago.
ago.The
Theexplosion
explosioncreated
createdthe
thecomplexity
complexityofofmulti-celled
multi-celledorganisms
organismsininaarelatively
relativelyshort
shorttime
timeframe
frameofof55
million
to 10 million years. This explosion also created most of the major extant animal groups today
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Enrichment 20 mins
The Anthropocene
1. Present to the learners a new proposed Epoch, the Anthropocene.
I. What are the evidences that suggest that we are entering/ have entered a new epoch?
II. How do scientists decide if a new finding should be validated?
2. This can be discussed in a small group of 5 learners.
Teacher Tip: Ask the learners to research if there are evidences to support that the “explosion” is as sudden
and spontaneous as it is used to describe the fossil record.
This is also a good time to discuss how new findings can affect an existing body of knowledge.
Let the learners read the following articles about a proposed new epoch, the Anthropocene.
• Human impact has pushed Earth into the Anthropocene - http://goo.gl/ fxggQf (04/13/16)
• What Is Anthropocene and Are We in It? - http://goo.gl/mq7I9V
http://goo.gl/mq7I9V (04/13/16)
• Welcome to the Anthropocene - http://www.anthropocene.info (04/13/16)
Evaluation 10 mins
EVALUATION (10 MINS)
1. Geologically speaking with reference to the entire history of the earth, the dinosaurs went extinct…
A. Shortly after the formation of Earth
B. In the first billion years of Earth’s history
C. In the most recent 2% of the history of Earth
D. Before the first fish formed
2. Relative to the percent of time dominating the surface of Earth which organisms have the longest reign?
A. Dinosaurs
B. Plants
C. Prokaryotes
D. Eukaryotes
E. Humans
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3. The Earth is ________ years old.
A. 6,000
B. 46,000,000
C. 4,600,000,000
D. There is no way to know
4. 100,000 years in the geologic history of Earth would be considered
A. Immensely long
B. A drop in the bucket
C. Half of Earth's history
D. An extremely significant amount of time
5. Understanding geologic time is significant because it helps us
A. Understand humans’ impact on our environment
B. Understand the evolution of organisms over time
C. Understand the possibility for life on other planets
D. Understand the process of evolution
E. All of the above
6. Which organism first dominated Earth?
A. Dinosaurs
B. Insects
C. Plants
D. Fish
E. Bacteria
Assignment 1 mins
1. What are fossils? How are they formed?
2. List down the types of fossils and given examples.
3. How do we measure the age of fossils?
4. What are mass extinctions? How many mass extinctions events happened in the GTS?
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Answer Key:
Answer with discussion must be given by the teacher.
1. C
2. C
3. C
4. B
5. B
6. E
Teacher Tip: See to it that everyone has a clear understanding of the geologic time scale. There is no need to
remember all the events in each period.
Download Teaching Guide Book 0 mins
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