At one point, thousands of years ago, there were only a handful of humans on earth. Because these people found comfortable climates to live in with fruits and vegetables to gather and eat, they were able to live and multiply. When herds of other animals came to eat their food supplies, humans chased them away. As this continued, humans learned and experimented with different ways to deal with the invading animals, such as throwing stones at them. This most likely evolved into the creation of spears to kill them more easily. But this led to rotting carcasses that smelled and led to other animals eating them. This most likely led to the man burning the animals they had speared in the village field fire to get rid of the body, but as the animals cooked over the fire, they realized that sometimes they would smell good aromas instead of bad ones coming from the animals . , then they tried to taste them and began to eat them. This opened the door to greater food availability as humans became both hunters and gatherers of food. As the men of the tribe were able to bring more food to the village, they decided to make more children with the woman as they knew they could feed them. This has led to constant population growth and the spread of humans across more and more lands. As the men argued about who was in charge, they appointed kings over the lands so that everyone would know who was in charge. As time passed, kingdoms grew and more kingdoms were created in new places. Humanity has become better farmers and traders to support larger populations and communities. As long as humans could find reliable sources of fresh water and build sufficient shelter for themselves, the population would continue to grow. If food and water sources became scarce, the population would stop increasing. If the climate changed, such as with repeated harsh winters, mortality rates would rise and population levels would stop growing. This could cause a tribe to move in search of a more suitable climate in which to live. Wars and natural disasters would also lead tribes to move in search of more favorable living areas. Say no to plagiarism. Get a tailor-made essay on "Why Violent Video Games Shouldn't Be Banned"? Get an Original Essay Population ecology is the study of population change over time. A population can consist of a country, a city, or a specific geographic location or region. Population density refers to how many people live in a given area. For example, a city that has condominiums, apartments, and multi-story homes in close proximity to each other will have a high population density. Where houses are spread out and there are no multi-level residential structures, population density will be lower. The advantage of high population density is that people are close together and can work together easily. One disadvantage is that if a natural disaster occurs in a high-density area, there is more likely to be more deaths, which affect the population. Another factor to consider is the age structure of the population. If 90% of the population is over the age of 60, it is a safe bet to assume that in the next 20 years there will be a drastic decrease in the population. But if 90% of the population is under 30 years old and life expectancy is still 80 years old, it can be safely assumed that the population will only increase for the next 50 years. As humans have become more technologically advanced, the human population has grown much more rapidly. For example, in the 1920s, automobiles were first producedtime in series to be purchased by the public. This gave humanity the ability to travel much further and much more easily. This gave people the opportunity to wander more and seek more favorable areas to live. Easier access to more favorable living environments has led to population growth. The automobile also gave humanity the ability to obtain medical care much more quickly when needed, as doctors and medical personnel could quickly reach the patent. This saved lives and slowed the mortality rate, therefore allowing the population to increase further. Vehicles have also given humans the ability to transport goods much more easily. Allowing construction materials to be transported to multiple areas much more easily. This gave the same number of men the ability to build homes in a much larger geographic area, allowing the community to spread and expand. Medical technology has advanced in numerous ways, curing diseases and creating preventable cures. This allowed people to live longer, slowing the mortality rate of human populations. This is one of the reasons why the human population has increased significantly. According to Reuters, “Researchers found that in 1,710 U.S. high schools equipped with AEDs, nearly two-thirds of cardiac arrest victims survived. This compares with a typical survival rate of only about 5% when cardiac arrest occurs outside of the hospital.” (para. 4). This is just one example among hundreds, perhaps thousands, that demonstrate that medical technology is saving lives and therefore reducing the mortality rate, thus allowing the population to increase. Modern culture has slowed population growth somewhat. For example, China has a one-child law for those living in cities, limiting each family to just one child. The Chinese government imposes fines or even forced sterilization if citizens have more than one child. According to about.com, China's one-child law "is estimated to have reduced the country's population growth of 1.3 billion by as much as 300 million people in its first two decades." (par. 2). In the United States there is an organization called Planned Parenthood. Planned Parenthood offers contraceptives and sex education. This organization helps limit unwanted pregnancies, which somewhat limits the birth rate of communities. Nutrition can play a role in the population. People who eat well tend to live longer than people who don't eat so well. According to CE Evoluzione Collettiva “The number one cause of heart disease is the food we consume”. (para. 1) Communities that provide healthier foods and educate young people about the importance of a good diet will have healthier and longer lifespans. According to ehow, an ecological footprint is “a measure of how much land, water, and natural resources a person, city, country, or humanity as a whole requires to produce the resource they consume.” (par. 1) Since the 1980s, humanity has expanded its footprint, thus taking more than it can replenish. If the human population continues to grow as expected, cities will become larger, produce more waste, and consume more natural resources. This will create an even larger ecological footprint, diminishing food supplies such as fishing and clearing more forests for materials. If left unchecked, increased deforestation and human waste will cause enormous environmental problems in the long term. If this continues long enough, the earth will eventually reach its carrying capacity. If humanity's ecological footprint increased relative to the earth's carrying capacity, the population.