Reader Response Exercise

Mubarak A. Abdella
ESL 91
Fall, 1999

FOCUS DISCIPLINE: PHYSICAL ANTHROPOLOGY

PROJECT TOPIC:There are two primary theories about how the human race evolved. These theories are (1) The Mitochondrial DNA theory and (2) The Multiregional theory. Research and explain each of these theories. Which of the two theories do you believe is a more probable explanation of the evolution of the human race? Why?

Introduction

Human evolution is a very interesting topic of research, and there are many theories that have tried to give an exact idea about how the life of modern humans started and where the humans came from. One of these theories is called the "Mitochondrial DNA" theory and another theory is called the "Multiregional theory."

These theories gave some answers to the question that says "where did we come from?" These theories have different suggestions about the origin of the modern human. This essay will explain what the Mitochondrial DNA and the multiregional theories are and how they attempt to explain human evolution.

The Mitochondrial DNA Theory

Mitochondrial DNA is a small part of the human genome contained outside the nucleus of the cell in the energy generating mitochondria. This particular feature passes through generations between females only. The Mitochondrial DNA shows a great deal of individual diversity. This fact supported the idea that these individual genetic diversities can help to trace the evolutionary history of human females. Researchers believe that the genes in the nuctieds sequence lead to diversity, and the genetic characteristics gather in a particular order in the isolated population making these populations able to split over the world.

One of the most important findings came from analyzing DNA from Asians, Europeans, and Africans. The scientists found that the diversity among African populations is greater than among other populations. According to Lynn Jorde, the U.S associate chairman of human genetics, "that’s consistent with Africa containing the source population from which modern humans arose 100,000 years ago." The Mitochondrial DNA theory holds that modern humans emerged from earlier humanoids in Africa 100,000 to 20,000 years ago, and migrated to Asia and other parts of the world. All the research and findings supported the evolutionary theory of mitochondrial DNA which suggested that all human life evolved from one woman who was born and lived in Africa about 200,000 years ago.

The Multiregional Theory

On the other hand, the Multiregional Theory says that there was a small group that began in Africa and this group was not modern humans, but it was Homo Erectus. The Multiregional Theory says that this Homo Erectus group split all over the world before they evolved into modern humans. The map shows how and when this happened.

These Homo Erectus lived in different environments, and they began to evolve through natural selection, and genetic evolution. With time they began to look a little different in different places, because of the effect of these different environments. The Multiregional Theory says that genetic evolution is a result of natural selection, which caused a developing of their characteristics and the diversity that began to appear among them.

The Multiregional Theory also says that there were no modern humans in Europe until 50,000 years ago and that the people who lived in Europe were Neanderthals. We can guess that they developed into modern Europeans. In the Far East before 50,000 years ago these ancestors evolved into modern Far Easterners, modern Chinese, modern Indians, and whatever. There is no specific evidence to prove this theory, but some basic evidence appeared in the Far East, Europe and Africa. This evidence showed that there are similarities between very old civilizations.

My Response

Working on this project taught me a lot of useful ways of finding the information that I need to know. For example, I learned new techniques of searching on the Internet. I also learned new information about the human evolution theories, and how people have a lot of diversities. In addition to that, when I studied about the human evolution theory, I learned vocabulary that helped me to improve my writing skills, which is so important to me in my future. This topic also allowed me to have a clear idea about physical anthropology, which I was unfamiliar with, and which I was hoping to learn more about.

The theories of human evolution are a lot, and they have a lot of diversities. The Mitochondrial DNA and the Multiregional Theories gave a very close look to the human evolution, but I believe that the Multiregional Theory is more correct than the Mitochondrial DNA Theory. There is some evidence that supports the Multiregional Theory, such as the fact that people have different characteristics throughout the world. That means that people probably did not evolve from one modern human who was a woman, as the Mitochondral DNA Theory says. If the Mitochondrial DNA Theory were correct, the difference in people's genetic characteristics would be very little because all the people would have inherited very similar genetic characteristics from this woman.

Conclusion

Finally, we can say that these two theories represent different ideas about human evolution. The Mitochondrial DNA Theory of evolution determined that modern human evolved in Africa; in contrast, the Multiregional Theory determined that modern humans did not evolve in Africa, but they evolved from Homo Erectus after Homo Erectus split over the world.