People and the Earth's Ecosystem Module 2 PDF

Module in People and the Earth's Ecosystem Module PREPARED BY: JEMUEL B. LAGARTO, LPT 1 Preface Welcome to People and the Earth’s Ecosystem, an interdisciplinary study of how the earth works, how humans interact with it, and how we can addr...

Module in People and the Earth's Ecosystem Module PREPARED BY: JEMUEL B. LAGARTO, LPT 1 Preface Welcome to People and the Earth’s Ecosystem, an interdisciplinary study of how the earth works, how humans interact with it, and how we can address the world's environmental issues. The concepts, facts, and issues presented in this module and the course you are taking will be beneficial to you now and in the future since environmental issues touch every aspect of your life. This module is designed to enhance students understanding of basic ecology concepts in three major areas: (1) Population, (2) Ecosystem, and (3) The Anthropogenic Impact to Environment. This module comprises of three series, module 1, module 2, and module 3 and it is divided based on the grading period during the school term, prelim, midterm, and finals. This module is centered in addressing the concern of the changing environment due to climate change and what can we do about it. Varied activities are provided in each chapter to help the students to develop important 21st century skills such as effective communications skills; learning and innovation skills; and information, media, and technological skills despite the pandemic. The components found in this module are as follows: Core Case Study - This presents article or research or case study for additional information.  Key Questions & Concepts - These are essential questions that students need to answer and understand. Big Idea - These are pop-up sections placed in the discussions to so that the students can easily identify essential concepts. Wordstorm - This is a vocabulary section to help the students to understand difficult terms. Gear Up - This is a set of enrichment activities. Self-Check - This is a 10-20 items test that includes formative and summative questions. As the students go through the pages of this module, may it be their desire to explore the world around them, observe the changes, and realize their role in protecting and conserving our ecosystem. The Author  unit 1 The Human Population 1  Chapter 1 As you go through this chapter, you will be able to: Define what population is; Enumerate the different characteristics of Population population; Calculate the birth rate, mortality rate and natality Characteristics rate of a population; Differentiate the two types of population growth curve, the S-curve and the J-curve; and Identify the two factors affecting the birth rate of a population. 2  1 Are There Too Many Of Us? CORE CASE STU DY According to one view, the planet already has too many people collectively degrading the earth’s natural capital. To some Each week, about 1.6 million people are analysts, the problem is the sheer number added to the world’s population. As a of people in developing countries with 82% result, the number of people on the earth is of the world’s population. To others, it is projected to increase from 6.7 to 9.3 billion high per capita resource consumption or more between 2008 and 2050, with most rates in developed countries—and to an of this growth occurring in the world’s increasing extent in rapidly developing developing countries. This raises an countries such as China and India—that important question: Can the world provide magnify the environmental impact, or an adequate standard of living for a ecological footprint, of each person. projected 2.6 billion more people by 2050 Many argue that both population growth without causing widespread and resource consumption per person are environmental damage? There is important causes of the environmental disagreement over the answer to this problems we face. question. Another view is that technological advances have allowed us to overcome the environmental resistance that all populations face and to increase the earth’s carrying capacity for our species. Some analysts argue there is no reason we cannot continue doing so, and they believe that the planet can support billions more people. They also see a growing population as our most valuable resource for solving environmental and other problems and for stimulating economic growth by increasing the number of consumers. As a result, they see no need to control the world’s population growth. 3 Some people view any form of population and environmental conditions in some regulation as a violation of their religious areas, as is already happening in parts of or moral beliefs. Others see it as an Africa. intrusion into their privacy and their freedom to have as many children as they Second, resource use and environmental want. These people also would argue degradation may intensify as more against any form of population control. consumers increase their already large ecological footprints in developed Proponents of slowing and eventually countries and in rapidly developing stopping population growth have a countries, such as China and India. This different view. They point out that we are could increase environmental stresses not providing the basic necessities for such as infectious disease, biodiversity about one of every five people—a total of losses, water shortages, traffic congestion, some 1.4 billion. They ask how we will be pollution of the seas, and climate change. able to do so for the projected 2.6 billion more people by 2050. This debate over interactions among population growth, economic growth, They also warn of two serious politics, and moral beliefs is one of the consequences we will face if we do not most important and controversial issues in sharply lower birth rates. First, death rates environmental science. may increase because of declining health 4  Population Growth Lesson Key Questions and Concepts 1 1. What is population? 2. What factors influence the size of the human population? 3. How does a population’s age distribution affect natality and mortality? 4. How can we slow human population growth? Each species in an ecosystem exist as a population. Members of a population rely on the same resources, are influenced by similar environmental factors and are bred with one another. In other words, a population (synonymous with biological population) consists of a group of interbreeding or potentially interbreeding organisms found in the same space or Big Idea area area same at the same time. The study of populations (especially population abundance) and how they change over time is called population ecology. It A population is a group of individuals studies the spatial and temporal patterns in the of the same species that live together in abundance and distribution of organisms and of the a region. mechanisms that produce those patterns. The study of population ecology includes understanding, explanation and prediction of population growth, regulation and dynamics or demography. Multicellular organisms are of two kinds, unitary organisms and modular organisms. Most animal populations are made up of unitary organisms. In unitary organisms, the form is highly determinate consisting usually of a strictly defined number of parts (such as legs or wings) established only during embryogenesis. Their pattern of development and final form are predictable. For example, all dogs have four legs, all squid have two eyes, etc. In modular organisms, on the other hand, neither timing nor form is predictable. These organisms grow by the repeated iteration of modules, usually to yield a branching pattern. Examples of modular organisms include plants and many sessile benthic invertebrates. In modular organisms, a single genetic individual (or genet) can consist of many modules (or ramets) capable of existence as individuals. In plants, a genet is an individual that has arisen from a seed. A ramet is a new plant which has arisen through vegetative propagation and is now a completely independent plant with its own roots and shoots. For example, a population of grasses may consist of several genets, each of which has several ramets. 5  Population Growth POPULATION CHARACTERISTICS A population has several characteristics or attributes which are a function of the whole group and not of the individual. Different populations can be compared by measuring these attributes. These attributes are population density, natality, mortality, distributions, etc. The study of the group characteristics of a population, their changes over time and prediction of future changes is known as demography. I. Population Density The size of the population is represented by its fundamental property called density. It is generally expressed as the number of individuals or the population biomass per unit area or volume. Two Types of Densities 1. Crude Density - Crude density is the density per unit of total space. Generally, populations do not occupy all the space as whole because all area may not be habitable. 2. Specific (or Ecological) Density - Specific density is the density per unit of habitable space. It includes only that portion of total space that can actually be colonized by the population. Determining Population Size Population size can be measured by several methods: 1. Abundance - Absolute number of individuals in population. 2. Numerical Density - Number of individuals per unit area or volume. It is expressed when the size of individuals in the population is relatively uniform, as in mammals, insects and birds. 3. Biomass Density - Biomass density is expressed in terms of wet weight, dry weight, volume, and carbon and nitrogen weight per unit area or volume. 6  Population Growth Population density can be calculated by the following equation: Dp = N A In this equation, Dp is the density of population, N is the total population as a number of people, and A is the land area covered by that population. A is usually expressed in terms of either square miles or square kilometers, especially when looking at human population. However, we could use smaller units as well. For example, if we're looking at the population density of a type of insect on a tree, we would use square feet or square meters, because kilometers would be far too large. We might also use acres if we're looking at the population density of cattle on a ranch. The same population density formula applies to both human and non-human populations. II. Natality Natality refers to the rate of reproduction or birth per unit time. It is an expression of the production of new individuals in the population by birth, hatching, germination or fission. Number of births per year Birth rate or Natality (B) = x 1,000 Number population per year The maximum number of births produced per individual under ideal conditions of environment is called potential natality. It is also called reproductive or biotic potential, absolute natality or maximum natality. Natality varies from organism to organism. It depends upon the population density and environmental factors. It is a general rule that if the population density is usually low, the birth rate is also low. This is so because the chances of mating between males and females are low. If population density is unusually high, the birth rate may also below due to poor nutrition or physiological or psychological problems related to crowding. The maximum or absolute natality is observed when the species exists under ideal ecological and genetic conditions. The actual number of births occurring under the existing environmental conditions is much less as compared to absolute natality. It is referred to as ecological natality or realized natality. It is not constant for population and may vary with the size of population as well as with the time. III. Mortality Mortality refers to the number of deaths for every 1,000 people per year. The death rate is correlated with the conditions of country, for example, with the levels of prosperity, health, or the occurrence of war. 7  Population Growth Mortality rate = Number of birth per year x 1,0000 Number of population per year Mortality can be expressed in the following two ways: 1. Minimum or Specific or Potential Mortality: - It represents the minimum of theoretical loss of individuals under ideal or non- limiting condition. Thus, even under the best conditions individuals of a population would die of old age determined by their physiological longevity. So it is constant for a population. 2. Ecological or Realized Mortality: - It refers to the death of individuals of a population under existing environmental conditions. Since it varies with environmental conditions, it is never constant. The maximum mortality occurs at the egg, larval, seedling and old age. Mortality is affected by a number of factors, such as, density, competition, disease, predation and environment. Death rates vary among the species and are correlated with birth rates. When the rate of natality is equal to the rate of mortality the population is stationary. A birth death ratio (Births/death x 100) is called vital index. For a population, the survival of individuals is more important than the death. The number of births in relation to the carrying capacity of the habitat is a fundamental factor influencing the mortality rate. When more young’s are born than the habitat can support, the surplus must either die or leave the area. Because the number of survivors is more important than the number of dying individuals, mortality is better expressed as survival or as life expectancy. The life expectancy refers to the average number of years the members of a population have left to live. IV. Population Growth The growth is one of the dynamic features of species population. Population size increases in a characteristic way. When the number of individuals of population is plotted on the y-axis and the times on the x-axis, a curve is obtained that indicates the trend in the growth of population size in a given time. This curve is called population growth curve. There are two types of growth curves: 1. Sigmoid Curve (S-Curve) When a few organisms are introduced in an area, the population increase is very slow 8  Population Growth slow in the beginning (positive acceleration phase or lag phase), in the middle phase, the population increase becomes very rapid(logarithmic phase) and finally in the last phase population increase is slowed down (negative acceleration phase) until an equilibrium is attained and which the population size fluctuates according to variability of environment. The level beyond which no major increase can occur is referred to as saturation level or carrying capacity. In the last phase the new organisms are almost equal to the number of dying individuals and thus there is no increase in population size. In this way, one gets sigmoid or 5-shaped growth curve (Fig. 1). 2. J-Shaped Curve The second type of growth curve is J-shaped. Here in the first phase there is no increase in population size because it needs some time for adjustment in the new environment. Soon after the population is established in the new environment, it starts multiplying rapidly. This increase in population is continued till large amount of food materials exist in the habitat. After some time, due to increase in population size, food supply in the habitat becomes limited which ultimately results in decrease in population size. This will result in J-shaped growth curve rather than S-shaped (Fig. 1). J- Curve S- Curve Figure 1, J-curved and S-curved population growth curves. 9  Population Growth V. Age Distribution Age distribution is another important characteristic of population which influences natality and mortality. Mortality, usually varies with age, as chances of death are more in early and later periods of lifespan. Similarly, natality is restricted to certain age groups, as for example, in middle age-groups in higher animals. According to Bodenheimer (1958), the individuals of a population can be divided into pre-reproductive, reproductive and post- reproductive groups. The individuals of pre-reproductive group are young, those of reproductive group are mature and those in post- reproductive group are old. The distribution of ages may be constant or variable. It is directly related to the growth rate of the population. Depending upon the proportion of the three age-groups, populations can be said to be growing, mature or stable, and diminishing In other words, the ratio of various age groups in a population determines the reproductive status of the population. Rapidly increasing population contains a large proportion of young individuals, a stable population shows even distribution of individuals in reproductive age-group and a declining population contains a large proportion of old individuals. Young Mature Old VI. Population Fluctuations The size and density of natural population show a changing pattern over a period of time. This is called population fluctuation. There are three types of variations in the pattern of population change: 1. Non-fluctuating: - When the population remains static over the years, it is said to be non-fluctuating. 2. Cyclic: - The cyclic variations may be (a) seasonal, and (b) annual. Sometimes seasonal changes occur in the population and there are additions to the population at the time of maximum reproduction and losses under adverse climatic conditions. Common examples of seasonal variations are met in mosquitoes and houseflies which area abundant in particular season 10  Population Growth and so also the weeds in the field during the rainy season. When the population of a species shows regular ups and downs over the years, it is called annual cyclic variation. It appears in the form of a sigmoid curve with regular drops in population after peaks. 3. Irruptive When the change in population density does not occur at regular intervals or in response to any obvious environmental factor, it is said to be irruptive fluctuation. In this there is a sudden exponential or logarithmic increase in population density in short time followed by equally quick drop in population density due to deaths, and final return to normal level or even below that level. 11  Population Growth Self-check 1 Answer the following questions , choose your answer from the box below. Note: You will answer this activity on google form. Non-fluctuating 12 people/square mile 4 people/square mile Realized mortality Potential Natality S-curved Abundance J-curved Specific density 40 people/square mile 1. Density per unit of habitable space. 2. Absolute number of individual in population. 3. The population in a 300 square mile area is 1200. What is the population density? 4. Maximum number of births produced per individual under ideal conditions of environment. 5. It refers to the death of individuals of a population under existing environmental condition. 6. A described the tendency of a population to grow without limit to its size. 7. A pattern of population change where the population remains static over the years. 8. Pattern of growth in which, in a new environment, the population density of an organism increases slowly initially, in a positive acceleration phase; then increases rapidly, approaching an exponential growth rate. 9. A describe the tendency of a population's growth rate to slow or stop as resources become unavailable. 10. There are 240 people living in a 20 square mile land. Calculate its population density. 12  Chapter 2 As you go through this chapter, you will be able to: Cite factors that can affect the birth rate of a population; Birth, Death, & Compare the changes of population's number added every eleven years in the world using a table; Changes Identify the major causes of human population change; and Enumerate different ways on how can we slow the growth of population. 13  Population Growth Factors that Cause Populations to Change Population Ecologists classify factors causing changes in populations as either density- dependent or density in dependent factors. Density refers to the number of animals per unit area (usually measured in animals/hectare or animals/square kilometer). Density-dependent factors As the density of a population increases, the amount of resources available to each individual decreases, and the health of individuals decreases. As health decreases, mortality (death rate) increases and reproduction decreases. Thus, we may talk about density- dependent mortality or density-dependent reproduction. Density-dependent forms of mortality include parasites, disease, starvation, and predation. Density-independent factors Are those factors that act on a population independent of the size of the population. Typical density-independent causes of mortality are weather, accidents, and environmental catastrophes like volcanoes, floods, landslides, fire, etc. The rate at which animals reproduce is a basic component of population dynamics. The rate of natural increase is the difference between birth and death rates. It measures the degree to which a population is growing. Since birth and death rates are measured as the number of births (or deaths) occurring per 1000 population, the difference is divided by 10 to convert this rate into a percentage. 14  Population Growth Rate of Natural Increase = Birth Rate - Death Rate Natality 10 Wildlife biologists usually express birth rates as fecundity, which is the number of young produced per female over a given time period. Usually one year is the time period considered, but for smaller animals, especially those that may breed several times a year, a shorter time period may be selected. Thus, if a population of 1,000 female grizzly bears produced 200 young in a year, the birth rate, or fecundity, would be 200/1,000 = 0.2. A number of factors affect a population's birth rate: The amount and quality of food available determines if an individual has enough energy to reproduce. Animals that are in poor nutritional condition have fewer young and/or breed less often. Age at first reproduction is also an important factor in determining birth rate. Large, long- lived animals typically do not become sexually mature until they are several years of age. A vole or meadow mouse might become sexually mature and breed for the first time at 18 days. An Asian elephant on the other hand will typically be 9-12 years old when it first breeds. The birth interval is also important in determining birth rates. A vole might produce a litter of young every 30 days during the breeding season, but a grizzly bear may only reproduce every 3 or 4 years. The average number of young produced is of obvious importance in a population's birth rate. Some animals such as fish or amphibians produce 100's or 1000's of eggs (not all of them hatch of course), while many wildlife only have one young at a time. Potential population growth rates are related to fecundity rates. A doubling in the fecundity rate will more than double the population growth rate. 15  Population Growth Human Population Growth Should we worry about human population growth or not? Why? Man is relatively new in this world; although there are already animals of millions of years, modern man evolved only four hundred thousand years ago. During most of this period people lived from hunting and gathering of food. Our planet could feed about ten million people living in this way. Estimations say that ten thousand years ago between five and ten million people lived on earth. Our planet was at that time at or near the maximum population it could support. The average growth rate until then was almost zero then 0.005 percent per year. Table 1. World Population Number of years to add each billion (1991 estimate) Average growth% Billion Reached Year Years to Add since previous 1 1800 All human history 0.005 2 1930 130 0.5 3 1960 30 1.4 4 1975 15 1.9 5 1987 12 1.9 6 1998 11 1.7 7 2009 11 1.4 8 2020 11 1.2 9 2033 13 0.9 16  Population Growth Average growth% Billion Reached Year Years to Add since previous 10 2046 13 0.8 11 2066 20 0.5 12 about 2100 34 0.3 Anthropologists believe the human species dates back at least 3 million years. For most of our history, these distant ancestors lived a precarious existence as hunters and gatherers. This way of life kept their total numbers small, probably less than 10 million. However, as agriculture was introduced, communities evolved that could support more people. World population expanded to about 300 million by A.D. 1 and continued to grow at a moderate rate, but after the start of the Industrial Revolution in the 18th century, living standards rose and widespread famines and epidemics diminished in some regions. Population growth accelerated. The population climbed to about 760 million in 1750 and reached 1 billion around 1800. Major Causes of Human Population Change a) Agricultural Revolution Agricultural revolution, ten thousand years ago, made a great change to increase the human population. This was a transition from hunting and gathering of food for subsistence. It has created settlement, easy access for food and mortality reduction and increase life expectancy. b) Industrial revolution Around 1750 another revolution started in England, making an even faster growth possible: the Industrial revolution. Giving an average growth rate of 0.84% since the beginning of the industrial revolution, about seventeen times the previous rate. c) Progressing growth With the development and spreading of modern medicine and sanitation, the growth rate is still progressing. 17  Population Growth How Many People Can the Earth Support? Human population growth continues but it is unevenly distributed for most of history, the human population grew slowly. But for the past 200 years, the human population has experienced rapid exponential growth reflected in the characteristic J-curve. Three major factors account for this population increase. First, humans developed the ability to expand into diverse new habitats and different climate zones. Second, the emergence of early and modern agriculture allowed more people to be fed for each unit of land area farmed. Third, the development of sanitation systems, antibiotics, and vaccines helped control infectious disease agents. As a result, death rates dropped sharply below birth rates and population size grew rapidly. About 10,000 years ago when agriculture began, there were about 5 million humans on the planet; now there are 6.7 billion of us. It took from the time we arrived until about 1927 to add the first 2 billion people to the planet; less than 50 years to add the next 2 billion (by 1974); and just 25 years to add the next 2 billion (by 1999). The year 2012, the Earth is already supporting 7 billion people and perhaps 9.3 billion by 2050. Such growth raises the question of whether the earth is overpopulated The rate of population growth has slowed, but the world’s population is still growing exponentially at a rate of 1.22% a year. This means that 82 million people were added to the world’s population during 2008—an average of nearly 225,000 more people each day, or 2.4 more people every time your heart beats. Geographically, this growth is unevenly distributed. About 1.2 million of these people were added to the world’s developed countries, growing at 0.1% a year. About 80.8 million were added to developing countries, growing 15 times faster at 1.5% a year. In other words, most of the world’s population growth takes place in already heavily populated parts of world most of which are the least equipped to deal with the pressures of such rapid growth. In our demographically divided world, roughly 1 billion people live in countries with essentially a stable population size while another billion or so live in countries whose populations are projected to at least double between 2008 and 2050. 18  Population Growth This raises the question posed in the Core Case Study at the beginning of this chapter: How many people can the earth support indefinitely? Some say about 2 billion. Others say as many as 30 billion. This issue has long been a topic of scientific debate. Some analysts believe this is the wrong question. Instead, they say, we should ask what the optimum sustainable population of the earth might be, based on the planet’s cultural carrying capacity. This would be an optimum level that would allow most people to live in reasonable comfort and freedom without impairing the ability of the planet to sustain future generations. How Can We Slow Human Population Growth? As countries develop, their populations tend to grow more slowly demographers examining birth and death rates of western European countries that became industrialized during the 19th century developed a hypothesis of population change known as the demographic transition: as countries become industrialized, first their death rates and then their birth rates decline. According to the hypothesis, based on such data, this transition takes place in four distinct stages. Some analysts believe that most of the world’s developing countries will make a demographic transition over the next few decades mostly because modern technology can bring economic development and family planning to such countries. Others fear that the still rapid population growth in some developing countries might outstrip economic growth and overwhelm some local life-support systems. As a consequence, some of these countries could become caught in a demographic trap at stage 2. This is now happening as death rates rise in a number of developing countries, especially in Africa. Indeed, countries in Africa being ravaged by the HIV/AIDS epidemic are falling back to stage 1. Other factors that could hinder the demographic transition in some developing countries are shortages of scientists and engineers (94% of them work in the industrialized world), shortages of skilled workers, insufficient financial capital, large debts to developed countries, and a drop in economic assistance from developed countries since 1985. 19  Population Growth Figure 1.2 Four stages of the demographic transition, which the population of a country can experience when it becomes industrialized. There is uncertainty about whether this model will apply to some of today’s developing countries. Family Planning Family planning provides educational and clinical services that help couples choose how many children to have and when to have them. Such programs vary from culture to culture, but most provide information on birth spacing, birth control, and health care for pregnant women and infants. Family planning has been a major factor in reducing the number of births throughout most of the world, mostly because of increased knowledge and availability of contraceptives. According to the U.N. Population Division, 58% of married women ages 15–45 in developed countries and 54% in developing countries used modern contraception in 2008. Family planning has also reduced the number of legal and illegal abortions performed each year and decreased the number of deaths of mothers and fetuses during pregnancy. Studies by the U.N. Population Division and other population agencies indicate that family planning is responsible for at least 55% of the drop in total fertility rates (TFRs) in developing countries, from 6.0 in 1960 to 3.0 in 2008. Between 1971 and 2008, for example, Thailand used family planning to cut its annual population growth rate from 3.2% to 0.5% and its TFR from 6.4 to 1.6 children per family. Another family planning success involves Iran, which between 1989 and 2000, cut its population growth rate from 2.5% to 1.4%. 20  Population Growth Despite such successes, two problems remain. First, according to the U.N. Population Fund, 42% of all pregnancies in developing countries are unplanned and 26% end with abortion. Second, an estimated 201 million couples in developing countries want to limit the number and determine the spacing of their children, but they lack access to family planning services. According to a recent study by the U.N. Population Fund and the Alan Guttmacher Institute, meeting women’s current unmet needs for family planning and contraception could each year prevent 52 million unwanted pregnancies, 22 million induced abortions, 1.4 million infant deaths, and 142,000 pregnancy-related deaths. Some analysts call for expanding family planning programs to include teenagers and sexually active unmarried women, who are excluded from many existing programs. Another suggestion is to develop programs that educate men about the importance of having fewer children and taking more responsibility for raising them. Proponents also call for greatly increased research on developing more effective and more acceptable birth control methods for men. In 1994, the United Nations held its third Conference on Population and Development in Cairo, Egypt. One of the conference’s goals was to encourage action to stabilize the world’s population at 7.8 billion by 2050 instead of the projected 9.2 billion. The experiences of countries such as Japan, Thailand, South Korea, Taiwan, Iran, and China show that a country can achieve or come close to replacement level fertility within a decade or two. Such experiences also suggest that the best ways to slow and stabilize population growth are through investing in family planning, reducing poverty, and elevating the social and economic status of women. 21  Population Growth Empowering Women Studies show that women tend to have fewer children if they are educated, hold a paying job outside the home, and live in societies where their human rights are not suppressed. Although women make up roughly half of the world’s population, in most societies they do not have the same rights and educational and economic opportunities as men do. Women do almost all of the world’s domestic work and child care for little or no pay and provide more unpaid health care than all of the world’s organized health services combined. They also do 60–80% of the work associated with growing food, gathering and hauling wood and animal dung for use as fuel, and hauling water in rural areas of Africa, Latin America, and Asia. As one Brazilian woman put it, “For poor women the only holiday is when you are asleep.” Globally, women account for two-thirds of all hours worked but receive only 10% of the world’s income, and they own less than 2% of the world’s land. Also, about 70% of the world’s poor and 64% of all 800 million illiterate adults are women. Because sons are more valued than daughters in many societies, girls are often kept at home to work instead of being sent to school. Globally, some 900 million girls—three times the entire U.S. population—do not attend elementary school. Teaching women to read has a major impact on fertility rates and population growth. Poor women who cannot read often have five to seven children, compared to two or fewer in societies where almost all women can read. 22  Population Growth According to Thorya Obaid, executive director of the U.N. Population Fund, “Many women in the developing world are trapped in poverty by illiteracy, poor health, and unwanted high fertility. All of these contribute to environmental degradation and tighten the grip of poverty.” An increasing number of women in developing countries are taking charge of their lives and reproductive behavior. As it expands, such bottom-up change by individual women will play an important role in stabilizing population and reducing environmental degradation. 23  Population Growth Self-check 2 Write TRUE if the statement is correct, and write FALSE if the statement is incorrect. Note: You will answer this activity on google form. 1. The development of modern technology in the health sector and the discovery of new vaccines made the death rate grew fast. 2. Agricultural revolution made a great change to decrease the human population. 3. Density refers to the number of animals per unit area. 4. Empowering woman can help to slow down the growing rate of population. 5. Death caused by car accident is an example of density-independent factor. 6. Animals that are in poor nutritional condition have fewer young and/or breed less often. 7. Population growth rate tend to slowdown when the country is more developed. 8. Family planning is illegal in the Philippines because Christianity is the predominant faith in the country. 9. A 35 years old male was infected by covid-19 virus, he was advised to do a self- quarantine since it is not severe. After 3 days, the 35 years old male died due to the infection. This scenario is an example of density-independent factor of mortality. 10. Fecundity means the ability to produce offspring. 24  Chapter 3 Human Growth As you go through this chapter, you will be able to: Describe the situation of Philippines population as of in the the latest census; and Identify which region is the most populated in the Philippines Philippines; 25  Population Growth Human Population Growth in the Philippines The Philippine population is projected to reach 142 million by 2045. This signifies about 49 million persons added to the country’s population from 2010 to 2045, equivalent to an average annual growth rate of 1.21 percent. All regions are expected to increase in population but with varying rates of growth. Ten regions are projected to grow faster than the national average with five of these regions located in Mindanao. During the years 2010 to 2045, the Autonomous Region in Muslim Mindanao (ARMM) is projected to have the highest average annual growth rate of 2.12 percent. Caraga’s population growth rate of 1.72 percent ranks second with SOCCSKSARGEN, Davao Region and Zamboanga Peninsula following. In terms of population, CALABARZON remains the largest in numbers by 2045 (20.1 million), followed by the National Capital Region and Central Luzon with 14.5 million each. Western Visayas and Central Visayas are the other regions surpassing the 10-million mark, with 10.4 million each in 2045. Cordillera Administrative Region will continue to have the smallest population with 2.6 million in year 2045. 26  Population Growth Philippine Population Density (Based on the 2015 Census of Population) The population of the Philippines as of August 1, 2015 based on the 2015 Census of Population (POPCEN 2015) was 100.98 million persons. With a total land area of approximately 300,000 square kilometers, the population density of the Philippines in 2015 was posted at 337 persons per square kilometer. This represents an increase of 29 persons per square kilometer (9.4 percent) from the population density of 308 persons per square kilometer in 2010. In 2000, there were 255 persons residing in every square kilometer of land. Among the country’s 18 administrative regions, the most densely populated was the National Capital Region (NCR), with a population density of 20,785 persons per square kilometer. This figure is more than 60 times higher than the population density of 337 persons per square kilometer at the national level. This translates to an additional 1,648 persons per square kilometer (8.6 percent) from the 19,137 persons per square kilometer in 2010. The population density of the NCR in 2000 was 16,032 persons per square kilometer. The most sparsely populated region in 2015 was the Cordillera Administrative Region (CAR), with 87 persons per square kilometer. 27  Population Growth GEAR UP Answer the following questions concisely. Maximum of two sentences only. Note: You will answer this activity on google form. 1. Identify a major local, national, or global environmental problem, and describe the role of population growth in this problem. 2. Is it rational for a poor couple in a developing country such as Philippines to have four or five children? Explain. 3. Do you believe that the population is too high in (a) the world (b) the Philippines, and (c) the area where you live? Explain. 4. If you have given a chance to pass a law in promoting to slow the growth of human population, what will be the title and its rationale? 5. Some have suggested that the earth's population problem could be solved by sending people to space colonies, each comprising roughly 10,000 people. How many self-sustaining space stations would we need to build to accommodate the 82 million people added to the world's population this year, assuming we could build them? How many space shuttles would have to be launched each day for a year to counteract the 82 million people added to the population this year if each shuttle could transport 100 passengers? Determine whether this plan is a logical answer to the world's population problem based on your calculations. What impact would the shuttles' regular launches have on global warming? Explain. 28