Human Evolution & Development

By: Lauren Ashley

Evolution and Natural Selection

The gradual process of "Natural Selection" is a key factor in evolution that means "survival of the fittest." It is a process in which biological traits become either more or less common in a population in relation with the environment. If a trait was not needed, it gradually stopped being reproduced over and over again and then disappeared . Only the traits needed for survival were needed. (Hence "survival of the fittest")

"The Big Bang" and Other Theories

Some people believe that the earth was created by an extraordinary random burst of energy called the “Big Bang Theory.” Gradually, the energy cooled enough to make matter such as protons and hydrogen. Stars swirled together in giant clusters and formed galaxies, and burned up stars exploded and generated so much heat that they exploded and made elements and minerals. Because of all this, the Sun was created, as well as Earth. The Earth gradually developed chemicals in water that formed the inside of membranes, thus creating one-celled living organisms. These organisms reproduced for 3 billion years and adapted to different environments.Eventually, their cells stuck together to create multi-cellular creatures. Following this theory, it is believed that humans evolved from apes. Eons later, Africa has become the most diverse and evidential continent wholly supported by this theory. Another theory is that life emerged from nutrient-rich puddles of “organic soup.”


Hominids & Modern Humans

Culture and Language: What Makes Us Human?

The Ancestors of Humans:

About 7-million year ago, ape-like creatures roamed the world's forests. However, they started to move out of the forests and into plains and grasslands. Since they no longer needed to use their arms to get around, natural selection worked its process and longer legs were soon favored. (long arms weren't as much needed now). Now that their hands and arms were free, they could used them for other tasks such as hunting and gathering food and building tools or weapons.

These animals were the early ancestors of humans.

The Power of Speech:

Learning started to become a big part of everyday lifestyle. There was an increased sense of curiosity among, and when one group member learned how to do a new skill or task, they would teach everyone else so they too could do it. As early humans started to become increasingly skillful, they slowly started to control the sounds made by their mouths and make them into words. The need for improved voice control led to changes in throat design. These changes made it easier for them to choke while eating or drinking, but improved voice control outweighed this disadvantage. Because of this new language, it was easier to communicate, cooperate, and create closer relationships with each other.

The Development of Culture:

Because of the new language and way of communicating, new culture arose. People began to entertain each other with stories, show more respect for others, and find their place in the world. The development of language, laws, and customs marked a huge turning point in evolution. Evolution would now be more about evolving human cultures rather than evolving human bodies.

Human Migration:

Early humans lived in family tribes that moved around following herds of wild animals. They slept in caves or made simple shelters under trees, made their clothes from animal skins, and all-purpose tools were made. They spread across Africa, Europe, and Asia in waves of migration that continued for hundreds of thousands of years. Because of this migration, modern humans all share similar abilities to our last common ancestor, but we come in a variety of shapes and colors.

Agriculture & Humanity

Agriculture is said to be one of the best but also worst human creations. It can be good because it provides a numerous amount of food and resources. For most of our history we fed ourselves by hunting and gathering: we hunted wild animals and ate wild plants. Because of agriculture, humans no longer have to solely depend on hunting and gathering to get food. (it was very time consuming and used a lot of energy). The new surplus of food made job specialization possible. Also, populations, cities, and towns started to come into existence, centered around agriculture. More food=more people, so these populations, cities, and towns started to grow. However, it is also known as the "worst mistake in human history," because since agriculture replaced the long days spent hunting and gathering, people had more free time on their hands. This may seem like a good thing, but it really isn't. Now, humans don't work as hard, have more leisure time, and are lazier in general. Epidemics and sicknesses have developed from over-crowding and starvation (too much people), and people have more time to reproduce, causing more and more people to depend on agriculture for food. Because of this, food stocks might run low or even run out because of all the people that need fed.


Farming Pros & Cons

For farmers, who increasingly relied on a single crop, an attack by locusts or a drastic change in weather could result in famine. Also, while hunter-gatherers moved from place to place following animal herd, they left their trash and germs behind, while farmers remained in one place. Not only did this result in excessive garbage but they also shared housing and diseases with their domesticated animals.This caused disease to spread like wildfire among people and animals alike. In addition to the potential for illness and bad health, farming also resulted in the development of social classes and gender inequality. However, farming is also a good thing because it is a great food source and we no longer have to depend on hunting and gathering to find food. Farming is also a huge industry in most countries around the world, grossing a huge income, which helps support farmers and their jobs.