GC-PEE 101 - PEOPLE, EARTH AND ECOSYSTEM

economies of the countries involved. For the

WEEK 1 – THE HUMAN country of origin, it may lead to a loss of skilled
POPULATION labor (brain drain), but it can also alleviate
unemployment pressures. For the host country,
POPULATION CHANGES it often provides a labor force that can contribute
to economic growth through consumer spending
- refer to alterations in the size, structure, and and filling labor shortages.
distribution of populations over time.
- These changes are influenced by various factors, - TRIVIA: As of 2017, the number of international
including birth rates, death rates, immigration, migrants reached approximately 280 million,
emigration, and other demographic, social, indicating a growing trend in global migration.
economic, and environmental factors.
3. FERTILITY RATES AND LIFE EXPECTANCY
WHY DO POPULATIONS CHANGE?________ - Fertility rate: The average
number of children a woman is
1. BIRTH AND DEATH RATES expected to have during her
- Birth Rates: The number of lifetime.
live births per 1,000 people - Life Expectancy: The average
per year. High birth rates number of years a person is expected to live.
contribute to population
growth, while declining
birth rates can slow down
or even reverse population
growth.
- Death Rates: The number
of deaths per 1,000 people - A woman's fertility begins to decline in her early
per year. Advances in 30s, with a more pronounced decrease after age
healthcare, sanitation, and 35. For men, fertility also declines with age,
nutrition often lead to particularly after 40, affecting the chances of
lower death rates and conception
longer life expectancy, - World's Oldest Person: The oldest verified
contributing to population growth. person was Frenchwoman Jeanne Calment, who
lived to 122 years. Her longevity has been a
subject of interest, with some speculating about
Here are some of the key reasons why birth rates
the accuracy of her age.
might be high:

- Value of Large Families: In many cultures, large 4. ECONOMIC, SOCIAL AND CULTURAL FACTORS
families are valued and seen as a sign of - Economic: Economic
prosperity and social status. This can encourage conditions can impact
higher birth rates. Religious Teachings: Certain population changes. For
religions promote the idea of procreation and example, economic
discourage contraception, leading to higher birth opportunities might attract
rates. people to certain areas,
while economic decline
- Lack of Social Security: In the absence of robust might push people away.
social security systems, families may have more - Social and Cultural:
children to ensure that some will survive to
Changes in social norms,
support them in old age.
cultural attitudes, and
- Limited Access to Contraceptives: Lack of access lifestyle choices can also
to or knowledge about contraceptives can lead influence population trends.
to higher birth rates.
5. GOVERNMENT POLICY
- Pro-Natalist Policies: Some governments - Policies such as family planning programs,
actively encourage higher birth rates through immigration laws, and incentives for larger
incentives such as tax breaks, subsidized families can significantly impact population
childcare, and parental leave. trends.

2. IMMIGRATION AND EMIGRATION

- Immigration: means the act of
coming to your own country.
- Emigration: means the act of
leaving your own country.

- Emigration can have both positive

and negative effects on the
G.P.B. A.Y. 2024-2025 2ND SEMESTER
 GC-PEE 101 - PEOPLE, EARTH AND ECOSYSTEM
- Population changes can have wide-ranging 2.) Random Pattern
effects on economies, healthcare systems, - Populations dispersed without a specific order.
infrastructure, and more. Understanding these - Territorial animals, such as many bird species,
dynamics helps governments and organizations often exhibit regular dispersion as individuals
plan for future needs and challenges. maintain a specific distance from one another
to reduce competition.
HUMAN POPULATION DYNAMICS
- refers to the study of changes in population size, 3.) Linear or Regular Pattern
composition, and distribution over time. This - Populations aligned along a line, such as rivers,
field encompasses various factors, including transportation routes, or mountain ranges.
birth rates, death rates, immigration, emigration, - Individuals are distributed without any
and how these factors interact with social, predictable pattern. (Plants) This arrangement
economic, and environmental conditions. occurs when individuals do not interact strongly
- As the global population continues to grow and with one another. Random dispersion typically
change, effective policies and strategies will be occurs in environments where resources are
essential to manage the impacts of these abundant and evenly distributed, allowing
dynamics on society and the planet. individuals to settle wherever conditions are
favorable.
DESCRIBING POPULATIONS_____________
POPULATION GROWTH
A population is defined as a group of organisms of the
same species: - Biotic Potential – the
amount a population
- inhabit a defined geographic area at the same would grow if there
time. were unlimited
- generally rely on each other resources (not a
- rely on the same resources practical model)
- influenced by the same environmental factors because organisms
are limited in nature by amount of food, space,
CHARACTERISTICS OF POPULATIONS______
light, air or water, etc.
1.) POPULATION DENSITY - Intrinsic rate of increase (r)
- refers to the number of individuals that inhabit a - No population can increase its size indefinitely
certain unit of land or water area. - Intrinsic rate – is the rate at which population
- Example : Number of squirrels in a particular would grow
forest. - Indefinitely - for an unlimited
- Calculation: It is calculated by dividing the total or unspecified period of time.
population of an area by its land area. For - Carrying Capacity (K) – defined as the maximum
example, if a city has a population of 1 million population size that can be supported by the
and covers an area of 100 square kilometers, its available resources of the region.
population density would be 10,000 people per - Different geographic regions have different
square kilometer. carrying capacities for populations.

2.) POPULATION DISPERSION

POPULATION GROWTH MODELS__________
- refers to how individuals are spaced within a 1.) EXPONENTIAL GROWTH
region. - In an exponential growth model, population size
- refers to the spatial distribution of individuals increases at a constant rate over time in an
within a population. Understanding this concept unrestricted environment.
is crucial for analyzing ecological dynamics, - Common examples of exponential growth in
resource management, and urban planning. real-life scenarios include the growth of cells, the
returns from compounding interest from an
PATTERNS OF POPULATION DISTRIBUTION_
investment, and the spread of a disease during a
1.) Clustered Pattern pandemic.
- Populations concentrated in specific regions or Characteristics:
cities.
- Social animals, such as wolves or elephants, - Unlimited resources are assumed.
often form packs or herds for protection and - Population growth accelerates continuously.
cooperative hunting. Clumped dispersion often - The growth rate remains constant.
arises from uneven resource distribution, social
Limitations:
behavior, or environmental factors that favor
group living. - Assumes a constant environment, which rarely
occurs in the real world.
- Does not consider factors such as resource
limitations or competition.
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 GC-PEE 101 - PEOPLE, EARTH AND ECOSYSTEM
- As population levels off, it often fluctuates
slightly above and below carrying capacity.
- Reproductive lag
- Reproductive lag time is the time required for
the birth rate to decline and the death rate to
increase in response to resource limits.

2.) LOGISTICS GROWTH

- The logistic growth model accounts for
environmental limitations on population growth,
incorporating a carrying capacity, the maximum
population size an environment can sustain.
- On a planet with finite resources, all populations
of organisms, whether they be ants or humans,
experience growth that is subjected to
limiting factors.
STRETCHING CARRYING CAPACITY________

Characteristics: Adapt: Over time species may increase their carrying

capacity by developing adaptations.
- Incorporates a carrying capacity
- Population growth slows as it approaches the Move: Some species maintain their carrying capacity by
carrying capacity. migrating to other areas.
- Represents more realistic population dynamics Switch Habits: So far, changes have extended the Earth’s
in environments with limited resources. carrying capacity for humans.
Limitations: - An ecosystem's carrying capacity may fluctuate
- Assumes a constant carrying capacity, which may based on seasonal changes, or it may change as
not hold true in dynamic environments. a result of human activity or a natural disaster.
- Does not account for external factors that may For example, if a fire destroys many trees in a
affect population dynamics. forest ecosystem, the forest's carrying capacity
for tree-nesting birds will decrease.

REPRODUCTIVE STRATEGIES____________
1.) R-selected species
- reproduce early in life and often – high capacity
for reproduction – little care is given to offspring
– high numbers.
- Example: Bacteria, insects, algae
2.) K-selected species
- reproduce later in life, produce fewer offspring,
POPULATION GROWTH________________ and devote a significant amount of time and
energy to the nurturing of their offspring.
- Population grows rapidly with ample resources,
- Example: Humans, lions, cows
but as resources become limited, its growth rate
slows and levels off.
- Environmental resistance factors are things that
limit the growth of a population. They include
biotic factors - like predators, disease,
competition, and lack of food - as well as abiotic
factors - like fire, flood, and drought. The biotic
potential of a population is how well a species is
able to survive.
FACTORS INFLUENCING POPULATION
GROWTH____________________________
1.) Density Dependent Factors
- factors that are a result of the population size.
• Birth and death rates
• Increased predation
• Competition for food, water or space
• Disease
• Build-up of toxic materials

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 GC-PEE 101 - PEOPLE, EARTH AND ECOSYSTEM

2.) Density Independent Factors 1.) PRE-INDUSTRIAL STATE

- factors that limit population size regardless of - The first stage of the demographic transition is
the number of individuals. the pre-industrial stage. During this stage, the
• Fires population is stable, with both high birth rates
• Storms and high death rates. The death rates are high
• Volcanic activity because there is increased disease, minimal
• Floods medical care, poor sanitation, and limited food
• Earthquakes supplies.
• Slow rate of growth
WORLD POPULATION • High death rate
- The human population has been growing • High birth rate
exponentially for three centuries. • Harsh living conditions (environmental
- The most significant additions to human resistance)
populations are due to births.
2.) TRANSITIONAL STATE
• Total fertility rate (TFR): the average number of - In the second phase, the population's health
children a women has during her reproductive slowly starts to improve, and the mortality rate
years. starts to fall.
• Replacement-level fertility: the number of • Birth rate is high
children a couple must bear to replace • Better food, water, and health care
themselves. • Death rate is low
• Rapid population growth
POPULATION AGE STRUCTURE___________
3.) INDUSTRIAL STATE
- A population’s growth is dependent upon the
- Death rate is similar to the birth rate this is
number of people in young, middle, and older
because of better access to birth control, decline
age group.
in the infant mortality rate, increased job
- Populations with a large proportion of its people
opportunities for women, high cost of raising
in the pre-reproductive ages 1-14 have a large
children who don’t enter the workforce until
potential for rapid population growth.
after highschool or college
• Population growth is slow
• Birth rate drops
• Death rate is similar to birth rate

4.) POST INDUSTRIAL STATE

AGE STRUCTURE PYRAMIDS_____________ - Population approaches zero growth rate.
- Then, the birth rate falls below the death rate
and the total population size slowly decreases.
- 37 countries have reached this stage (mainly in
Europe)
- Birth rates diminish, as a rule accordingly of
enhanced economic conditions, an expansion in
women's status and education, and access to
contraception.

CALCULATING POPULATION GROWTH____

- 32% of the people in developing countries were - Net Change in Population = (Birth rate – death
under 15 years old in 2006 versus only 17% in rate) + (immigration – emigration) / 10
developed countries.
- Birth rate exceeds the death rate. Population is - If a population of 10,000 experience 100 births,
getting larger. 40 deaths, 10 immigrants and 30 emigrants in a
- Pyramid shaped histogram. year, what is the net annual percentage growth
- Example: Kenya, Nigeria and Saudi Arabia rate?
• Net change in population = (100 - 40) + (10 -
DEMOGRAPHIC TRANSITIONAL MODEL___ 30)
- Used to predict population trends based on • Net change in population = 60 - 20
birth and death rates. • Net change in population = 40
- 4 states population transition between:
1. Pre-industrial state
2. Transitional state
3. Industrial state
4. Post-industrial state
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 GC-PEE 101 - PEOPLE, EARTH AND ECOSYSTEM

CALCULATING NET ANNUAL GROWTH____ change did not lead to a sustained increase
in birth rates. Couples hesitated to have a
Net growth rate = (Net change in population / Initial second child for reasons such as concerns about
population) * 100% being able to afford another child, the lack of
available childcare, and worries about how
• Net growth rate = (40 / 10,000) * 100%
• Net growth rate = 0.004 * 100% having another child would affect their careers,
• Net growth rate = 0.4% especially for mothers.
- In May 2021 the Chinese government
SLOWING POPULATION GROWTH IN INDIA announced that all married couples would be
allowed to have as many as three children; this
AND CHINA__________________________
was formally passed into law in August 2021.
- For more than five decades, India has tried to
control its population growth with only modest PHILIPPINE POPULATION
success. - The current population of the Philippines is
- Since 1970, China has used a government- 115,959,497 as of Thursday, August 15, 2024,
enforced program to cut its birth rate in half and based on Worldometer's elaboration of the
sharply reduce its fertility rate. latest United Nations data.
- The Philippines population is equivalent to
1.42% of the total world population.

LIFE EXPENTANCY IN PHILIPPINES________

INDIA’S FAILED FAMILY PLANNING

PROGRAM___________________
• Poor planning
• Bureaucratic inefficiency
• Low status of women
• Extreme poverty
• Lack of administrative financial support

CHINA’S FAMILY PLANNING PROGRAM____

- Currently, Chinas TFR is 1.6 children per women. INFANT MORTALITY RATE AND DEATHS OF
- China has moved 300 million people out of CHILDREN
poverty
- Problem: Strong male preference leads to
gender imbalance.
- Strong male preference leads to gender
imbalance. Girls are aborted at a higher rate
than boys.
FAMILY PLANNING IN PINAS____________
- Family planning efforts in the Philippines have
faced several challenges that contribute to their
perceived shortcomings because of:

- Cultural and Religious Influences: The

Philippines has a predominantly Catholic
population, and the Catholic Church's stance
against artificial contraception.

- Socioeconomic Factors: Economic disparities

- Benefits:
can affect access to family planning services.
• Extra food
• Larger pensions - Education and Awareness: There is a need for
• Better housing better education and awareness regarding
• Free medical care reproductive health and family planning.
• Salary bonuses
• Free school tuition for their one child. - Younger generations, are opting to have pets—
• Preferential treatment in employment when sometimes referred to as "fur babies"—instead
their child enters the job market. of having children.
- Beginning in early 2016, all families in China 1. Economic Considerations
would be allowed to have two children, but that 2. Lifestyle and Career Priorities
G.P.B. A.Y. 2024-2025 2ND SEMESTER
 GC-PEE 101 - PEOPLE, EARTH AND ECOSYSTEM
3. Urbanization and Housing
4. Pet Advocacy and Awareness
5. Emotional and Psychological Benefits

1. Economic Considerations

- Raising children can be financially demanding.

The cost of education, healthcare, and other
child-rearing expenses can be significant. For
some, the economic burden of raising a child
might outweigh the financial commitment
required for pet care.

2. Lifestyle and Career Priorities

- Many individuals prioritize their careers and
personal freedom. Pets can offer
companionship and emotional support without
the extensive time and financial commitments
that raising children entails.

3. Urbanization and Housing

- Urban living can come with space constraints
that make pet ownership more feasible than
raising children. Apartments and smaller living
spaces may be better suited to pets, which can
also be more adaptable to changing living
conditions.

4. Pet Advocacy and Awareness

- Increased awareness about animal welfare and

the benefits of pet ownership can drive interest
in adopting pets. Pet care services, including
veterinary care and pet-friendly
accommodations, have also become more
accessible.

5. Emotional and Psychological Benefits

- Pets are known to provide emotional support,

reduce stress, and offer companionship. For
many, pets can fulfill the desire for nurturing
and connection, which might otherwise be met
by having children.

G.P.B. A.Y. 2024-2025 2ND SEMESTER