Human Evolution

By: William Henderer

Table of Contents

Introduction………………………………………………………………..…page 3 Chapter One: Body Changes…………………………………………………page 4 Chapter Two: Tools…………………………………………………………...page 8 Chapter Three: Culture………………………………………………………page 11 Chapter Four: Migration…………………………………………………….page 16 Chapter Five: Anthropology………………………………………………...page 20 Conclusion…………………………………………………………………..page 23 Works Cited…………………………………………………………………page 24 Images Cited………………………………………………………………...page 25

Introduction

I chose this topic because I have always been interested in why humans are so much more advanced than other species. I have definitely enjoyed doing the research and writing the paper. It was difficult at times, but I pulled through and got it done. The biggest questions I had were, “Why do we need to evolve?”, “How did we become so advanced?” and “How similar are we compared to each other?”. It took a lot of research to answer these questions, but I eventually found the answers. While researching I came across a theme to human evolution. Not many people realize this, but human evolution makes humanity what it is currently. When we look deeper into our origins, human evolution can vastly broaden our perspective. We can look at things around us and realize how long it took humans to develop things. It makes us think more about what seem to be simple things and piques our curiosity about what it means to be human.

Chapter One Body Changes

Human fossil records have helped us understand early humans. The first beings that closely resembled modern humans were living approximately one million years ago. The first hominids*, also known as human ancestors, lived in Africa about eight to six million years ago. Current fossil records go back only seven million years. The fossil records show immense amounts of information about the brain. The percent of body space that the brain takes up has grown from 1.2% to 2.75%. Chimpanzees have a low, small brain case. However, some early humans had long and large brain cases. Neanderthals, one of the more recent hominids, had large skulls and brains that were even bigger than modern humans. Just because neanderthals had a bigger brain, this did not mean they were more intelligent. *any member of the group consisting of all modern and extinct humans and great apes (including gorillas, chimpanzees, and orangutans) and all their immediate ancestors. Brain size between species varied quite a bit. Larger brains can overheat easily which may have caused hair loss. Interestingly enough, homo

heidelbergensis, who lived around 250,000 to 1,000,000 years ago, had a similar size brain to a modern human. In the past three million years, human brain size has nearly tripled. This could be the result of eating more protein on a regular basis. Brain size has dramatically changed human intelligence. Some hominids* developed adaptations to the environment in which they lived. Neanderthal heads were lower, longer, and had round eye sockets with heavy brows, and large teeth. Paranthropus robustus, who lived two to one million years ago, had a ridge on the top of its skull, strong muscles for chewing, and large grinding teeth. Australopithecus afarensis, who lived three to two million years ago, had small canine teeth, thick cheek teeth and thicker bones. Homo erectus, who lived 2,500,000 to 250,000 years ago, had strong chewing muscles, a dome shaped head, and flat wide face. All of these species fared well with these adaptations to the environment. *any member of the group consisting of all modern and extinct humans and all their immediate ancestors, specifically species more closely related to modern humans than to chimpanzees. Humans' skulls have changed dramatically from those of apes. Chins receded at ausrulopithuceus afarensis. Modern humans have a bone that keeps the tongue in one place letting humans make all kinds of sounds. The modern human skull is higher, more rounded with a flat face, and teeth and jaws are much smaller than apes.

The rest of the body changed immensely as well. Neanderthals had humongous bones, inflated chests, and were quite strong. Chimpanzees have longer arms than legs, unlike modern humans who have longer legs than arms. Australopithecus afarensis had big and strong arms. Like modern humans Australopithecus afarensis had an s shaped back, broad knees, and forward facing toes. These are only a few changes. Hominins' bodies started to look somewhat similar to modern humans 1.8 million years ago. Modern humans were the only living hominin species 30,000 years ago. Australopithecus garhi, who lived around 2.5 million had long legs which gave us the legs we have today. Our legs helped us survive, they helped us run from predators and go places faster. Evolution is supposed to help us reproduce, and that is how longer legs helped. They stayed with our ancestors, who passed them down to us. Arm and leg length has grown quite a bit relatively recently. Humans still have not changed that much in the past 100,000 years. It is harder for modern humans to reproduce because humans’ big heads put quite a bit of strain on our smaller pelvises. Neanderthals were probably able to survive the ice age because their small limbs lost heat slowly. Humans’ bodies have had some major changes in structure over the years.

Chapter Two Tools

As humans became more complex their tools became increasingly more complex with them. Tools looked very different, depending on where and when they were made. Most tools did one of the following: grind, chop, or cut. In different regions, tools would look different because the culture that used the tools may have used them in different ways. Gorillas do not use tools as much as chimpanzees, but they still will crack a nut with a rock. Chimpanzees on the other hand, will actually take a leaf and use it to get water out of a tree, they also will use leaves to shelter from the rain. Neanderthals hunted with spears and axes. There were various kinds of tools for many circumstances. Many species used different tools for hunting. Neanderthals mostly ate meat which they had to hunt for, also, they would eat fish and plants. Homo habilis cut open nuts and shells with rocks. They also used tools to crush bones for the fatty bone marrow inside. Tools were not only used for hunting. Sometimes humans would be buried with special tools. Many tools could help reach things. After the Ice Age, people started to farm and made tools to do so. Flint sickles were used to harvest crops. Small shovels were made to dig holes in the ground. People also made places to put crops to save for the winter. Tools were complex and hard to make. By taking a stone and hitting it against another stone you could chip off bits of rock and make a tool. Different types of rocks were better for other tools. A stone could be fastened to a shaft to make a thrusting spear. It can take a long time to make one tool.

There are four main steps in making a stone tool. The first step is burying the rocks and building a fire on top of them. The next step is to chip off flakes of stone. After that the rocks would be pushed down upon so the rocks shape into what tool the maker wants it to be. Finally use bones to make fine sharp tips. The type of rock used is important. Early stone tools were just rock grabbed off the ground. Tools were made from many different types of rocks, some better than others. Sometimes people would travel ten miles to find good rocks like obsidian. It can be hard to tell the difference between normal rocks and tools, however if the rock is not native to the area then it is probably a tool. Sometimes scientists put together pieces of chipped rock back together to make the original stone. Some rocks were valued deeply and for some strange reason, the largest tools were found in China, nobody knows why.

Chapter Three Art

There were two different periods throughout prehistoric art. The early period, which is associated with hand stencil spray painting ( with pigment not paint) and drawings of large animals. The later period consisted mostly of migrating humans on a stylistic background. The early period is dated about 39,000 years old. While the late period is dated to 10,000 years ago. In different time periods there were different art styles, this is still true today. Paint was essential for drawing all kinds of animals and people. People would work extremely hard to get paint. Haematite, limonite, and specularite can produce a wide variety of colors for paint. People would crush the minerals to get colored powder which they would use to paint. Some paint was specifically used as body paint. Some Scientists believe that color coding might have been a method of communication. Many people painted cave art in Europe. Over 90 different caves containing paintings have been found, but more are to be discovered. In caves people used red, yellow, brown, and black paint. Most of this cave painting happened 40,000 years ago. Cave painting is probably the most well known ancient painting that people did.

Art can show scientists what was around in the past. During December of 1994, three explorers came together to explore caves near Avignon, France. They found over 300 cave paintings of animals that were over 32,000 years old. Art like this can tell researchers about the animals that lived long ago without needing to find the bones. Using carbon dating they can find out when the painting was made thus telling them when the animals lived. That way if scientists found bones that fit together with each bone coming from a different dig site, they could check the time period and see if it matched. If it did they would know they had found parts to an animal that lived in that time period. We do not know why people painted, but there are some theories on why they might have done this. One theory is that people believed if certain hominids painted animals they hunted the person who painted it would have good luck hunting. Another theory is that they believed in spirits and that painting would make the spirits happy, then they would give them gifts in return such as good weather. It may be a mystery why people painted, but it must have been important because almost all paintings were in remote areas like in the back of caves. Some caves are tourist attractions and people come to look at the ancient art. However the paintings can be damaged easily, and when the tourists come into

the cave, their body heat raises the temperature in the cave which is not good for the paintings. When the tourists breath they put water vapor in the air which can cause the paintings to deteriorate. Although the paintings are interesting and fascinating, people should not see them in person unless they are scientists studying the painting. Painting was not the only form of expression through art, there are many other forms of ancient art expressions, some of which include sculpting, jewelry, and statues. For example beads were a very popular and valuable art form. Rich towns had gold and silver to trade for jewelry. Graves were rare and usually have been looted, but sometimes they had gold beads if the person buried was wealthy or in a high social class. Explorers found three graves in Russia. Each grave had 3,500 ivory beads surrounding it, which makes a total of 10,500 beads. It took about 45 minutes to make one bead. It would have taken a person 472,500 minutes to make all the beads or 7875 hours or 328 days of continuous work time to finish, assuming they were all made by one person. It is interesting to think about how long people spent making those beads. It would have been extremely important to them. Cycladic people were a culture that was cultivated in art. They used jars called pithoi to hold crops. They had many places to keep pottery. They also did intricate dances to honor the deceased. Cycladic people are best known for their white marble figurines. The culture may have died out but the artifacts live on. If people had something valuable to trade they could increase by buying everything. In Japan 18,000 years ago people started making pottery. The Greeks took over because they acquired weapons by trading pottery. They made trade routes for pottery and other items. The pottery was quite pretty and sold for a lot.

Having riches unfortunately does not make one invincible and eventually the Greeks fell. Farming was the first step into agriculture. Farming first began in an area named the Fertile Crescent. It was in the Middle East and had a great variety of plants and animals. The first farmers harvested grains using a tool called a sickle, which is a blade made like a crescent moon. The first farmers had to work things out, but they made it through the winters and survived. Later people used axes with stone blades to cut down trees, along with clearing more land to grow crops. People soon found out how to preserve food. For example, fish was dried in the sun while other types of meat were put in holes in cold areas. The holes were similar to our freezers. Goats were the first animal to be domesticated around 8,500 B.C.E.. Chickens and pigs followed. Farming was not perfect and battles broke out to protect their land and food, as well as attacking others to get more. Farming is a good thing for the environment that has been passed down as a skill and helped many generations of cultures.

Chapter Four Migration

There are two ways to study early human migration. The first way is to study fossil records and track movement. By comparing the dates of the fossil scientists can figure out when certain people were in different regions making a migration map. The second way is to look at living peoples genes and seeing how they change in different locations. The pattern of genetic change will also show a pattern of migration. People examine both, which is quite effective, one is not necessarily better than the other. The genus homo first appeared in Africa 2.5 million years ago, starting with H.Rudolfensis. Some hominids started migrating out of Africa 2 million years ago. There are many different theories on how and when hominids left Africa. One popular theory is that hominids came out of Africa using a land route over the Sinai Peninsula into Arabia and then onward to the Fertile Crescent of Mesopotamia. This has been confirmed by finds at Ubeidiya. Hominids reached southeast Asia 1.8 million years ago. Fossils in Trinil and Sangiran in Java confirm that Homo erectus had settled as far as Java 1.7 million to 1 million years ago. These people eventually migrated to Australia 60,000 years ago. The oldest artifact found in Australia is a stone shelter found in Malakunanja. This migration is sometimes called “the express train senario.” Early humans did not go only to the east from Mesopotamia, they also went north to Southern Europe. Hominin fossils and stone tools found in Georgia, Europe, and dated around 1,700,000 years ago reflect migration to Southern

Europe. Additional finds in Spain and England show early humans in Northern Europe 1,200,000 to 800,000 years ago. Not all of the early humans that migrated across Asia went southeast, some went North East into China around 1,600,000 years ago. A dig at Dragon Bone Hill in Zhoukoudian, China found H. Erectus fossils dated to 800,000 to 400,000 years ago. Asians migrated north into Siberia finding the arctic ocean 30,000 years ago, this was during the last Ice Age. Artifacts of ivory and bones found in Siberia dated back to 21,000 years ago, the peak of the last Ice Age. During the Pleistocene, a geologic era, which happened 2,600,000 to 12,000, years ago northeast Asia was connected by land to northwest North America. At the end of the last ice age around 14,000 to 13,500, years ago the ice had melted enough to reveal a land bridge. Early humans crossed the land bridge from Siberia into modern day Alaska. Dig sites in the Western U.S. found spearheads known as Clovis points that are 13,500 years old. Soon people migrated down to Brazil populating South America. A skull dated around 13,000 years ago in Sumidouro Cave provides evidence of this journey. In addition to looking at the physical records scientists also study genetics to figure out past migrations. People may seem very different, but a vast majority of humans genetic material is the same. The other 1% makes people an individual as a person. Scientists try to look for differences in that 1% and make patterns out of it. By comparing genetic material in fossils and comparing it to

genetic material in organisms, scientists can make predictions on migration patterns. This is an effective way to learn more about each other while learning about the past as well. There are two main techniques for doing this kind of research. The first is to look at mitochondrial DNA, which all humans inherit from their mothers and other female elders. By examining mitochondrial DNA scientists have made a global gene tree. This gene tree confirms our African origin and breaks down humans into sub-categories based on DNA. The second technique is to look at Y chromosomes, which men inherit from their fathers. Studying Y chromosome lineage can be used to suggest past migration routes. Both of these genetic studies confirm many migration routes that are suggested by fossils and artifacts. Modern genetic studies are important because they confirm evidence of migration.

Chapter Five Anthropology

Anthropology is the study of humanity, which is related to evolution. People used to only learn about the past from books and religious texts, but now humans have many ways to figure things out using science. Anthropology was first studied in the late 19th century. No one is quite sure who was the first to study anthropology. Anthropology is a broad topic. There are four main branches of anthropology; linguistics, cultural, physical, and archaeological. Physical Anthropology is mainly about differences in body structure, such as being different body parts, being taller or shorter than someone else. Archaeological Anthropology is mainly studying fossils. Cultural Anthropology is the study of people's cultures like how Egyptians mummified the deceased. Linguistic anthropology is about languages which are crucial to understand as there are about 6,000 human languages. Anthropology is an immensely vast topic to research and people who study it for their entire lives and only scratch the surface of anthropology. In life everyone faces challenges with other people, but if we trace our heritage back far enough we will find connections to each other making it silly to fight. In 1949, anthropologist Clyde Kluckhohn published his book Mirror for Man, an Introduction to Anthropology. Clyde said, “Anthropology holds up a great mirror to man and lets him look at himself in his infinite variety.” Which means anthropology shows anyone willing to look, about themselves. Many people believe modern humans are known as homo sapiens, but this is only the case when talking about anatomically modern humans.

When talking about behaviorally modern humans, they would be known as homo sapien sapien. Being anatomically modern means that you are indistinguishable from our current population. Being behaviourally modern is when you are physically indistinguishable from modern humans. Not many people know this, but it is important when referring to how modern a species is. Anthropology has been around for a while and recently anthropologists have gotten restless. By the 1960s anthropologists started to want to not only study humanity, but also to help it. They wanted to apply what they had learned and use it to solve modern day problems. Poverty was discussed amongst anthropologists, but they could not figure out a solution which is why most anthropologists gave up. Great advancements have happened since the study of anthropology began 150 years ago. Unfortunately only for the past 90 years has anthropology been a distinguished academic field. There are many parts to anthropology, but every one of them is important. Just like other species found on the planet the human species has many more secrets to be discovered.

Conclusion

My research on human evolution has taught me many things. First I learned that the study of human evolution, through anthropology, reveals much about our human ancestry. The fossil record provides physical evidence of our evolution. We have had remarkable changes over the past 8 million years. Our bodies have adapted based on what was best suited to our environments and survival. Also, as our brains grew bigger, humans developed more complex tools. Our tools further helped us adapt to our environments. Further, I learned that early humans found time to make art. This makes them more similar to people today. In fact, studies of human migration show how alike all humans are. One of the most prominent things I noticed about human evolution is that a vast majority of our human DNA is the same, meaning we are extremely similar to each other. Humans evolved in Africa and migrated to almost all parts of the globe. The fossil records and modern DNA studies confirm our migration from common ancestral roots. What I find the most revealing is that what we all have in common is greater than what sets us apart. No matter how different we may seem we all share a common humanity.

Bibliography

Aylala, Francisco, and Camilo Cela-Conde. Processes In Human Evolution. Harris, Eugene. Ancestors In Our Genome. Hoffecker, John F. Modern Humans: Their African Origin and Global Dispersal. Columbia University Press, 2017. https://www.dictionary.com/browse/ Pipe, Jim. Early People. Roberts, Alice M., et al., editors. Evolution: The Human Story. Second [American] edition, Revised edition, DK Publishing, 2018. Seddon, Christopher. Humans: From the Beginning: From the First Apes to the First Cities. 2015. Smith, Cameron M., and Evan T. Davies. Anthropology for Dummies. John Wiley & Sons, 2013. Zimmer, Carl. Smithsonian Intimate Guide to Human Origins. Smithsonian Books, 2005.

Images Cited https://pixabay.com/illustrations/dna-genetics-biology-science-3889611/ https://commons.wikimedia.org/wiki/File:Prehistoric_Rock_Paintings_at_Manda_ Gu%C3%A9li_Cave_in_the_Ennedi_Mountains_-_northeastern_Chad_2015.jpg https://en.wikipedia.org/wiki/Stencil https://www.shutterstock.com/search/skulls+human+evolution https://www.smithsonianmag.com/science-nature/the-human-familys-earliest-ances tors-7372974/ https://pixabay.com/vectors/evolution-evolving-mankind-men-ape-1295256/