Fossils: The Evolution Of Human Species

This chapter beings explaining the evolution of mankind. Prior to 11,000 BCE, all humans were equal. Due to our evolutionary past, we branched off from apes to humans and spread around the world. Nearly 4 million years ago, humans began their mark on earth in Africa. Jared Diamond compares human development on all seven continents about 13,000 years ago. Although many early humans were found primarily in Eurasia and Africa, over time they expanded and gained new territory. The early humans created tools as they evolved, and many became hunter and gatherers. Then, human history made a Great Leap Forward around 40,000 BCE. The Great Leap Forward was when the earliest humans created new technology and exciting innovations that did not exist previously

Looking at climate can be a huge part of when human evolution began. The climate during the last 6-7 million years when hominins evolved to modern humans was characterized by high variability. Climate can show many things an example that could be found is a river from millions of years ago that is now buried below land. This river can show hominins might have lived in that particular area, or that they could have been ago to live in that area. Research shows the importance of fresh water availability is for hominin survival, and it says that the need for swift and efficient movement between ever shrinking sources of

A mutation is a change made to the sequence of a base in the DNA. This change occurs mainly in the chromosomes or nucleotides; however, mutations that occur in a egg or sperm cell are the cause of generic variation. This mutation can be inherited by offspring.

Fossils are very important for the study of evolution, for they provide a record of how groups of organisms have been evolving throughout the years. Fossils of the same group of organisms show gradual changes over periods of time, and archaeologists use that to determine how they have evolved. They can also

anamensis was probably around the same size as a modern chimpanzee. However, there was a huge difference in body size between the males and females. This body difference between genders is an example of sexual dimorphism and was similar to the difference between modern gorillas and orang-utans. There is not much fossil evidence in regards to the brain size of A. anamenis but enough to determine that the species probably had a relatively small brain. Portions of the tibia that were discovered were human-like and as mentioned before, indicated that the species was able to walk on two legs (bipedalism). Marks on the wrist bones that were found showed that A. anamensis had strong hand tendons that would have been useful for tree climbing. As for the elbow joint, it showed that it was more human-like due to the flexible rather than the rigid elbows that four-legged apes have in order to be able to support their bodies as they move about. Also in regards to climbing, A. afarensis’ forearms were pretty long and ape-like so they could be used to climb

Another reason our genetic markers change over time is because we get diseases, also called a genetic disorder. A genetic disorder is a disease that is caused by a change or mutation in an individual’s DNA sequence.

Over the course of human history, the human genome has not only grown but diversified. From the beginning of time, the human race has been through three forms (change) that have changed the course of history. The earliest hominid race on the planet was Homo Erectus or upright man. The earliest fossil evidence of this primate is 1.9 million years ago. The Homo Erectus ranged from height anywhere from 4 ft. 9 in. to 6 ft. 1 in. And in weight from 88 to 150 pounds. The Homo Erectus was the first species to live life on the ground with body adaptations such as longer legs and shorter arms indicating the loss of tree-climbing adaptations. This was also the first species to traverse beyond Africa. Along with this spreading of the species, it is associated

Over a time period of millions of years, scientists believe that humans have developed from ape-like ancestors. All humans are primates and modern humans are known as a species called, homo sapiens. They are very closely alike in physical and genetic appearance with another primate species, apes. Much of human evolution occurred in Africa because that is where humans began changing. Scientists have recognized 15 to 20 different species of early humans. There are fossils of early species of people that come completely from Africa. Over that past 4 million years, humans have gained many defining traits that are different than what the fossils of early humans show. Bipedalism is the ability to walk on two legs and it is one of the earliest traits of a homo sapien, or the human species. While looking at the pieces of bone, foot prints, and tools that were left behind but preserved naturally, you can see how humans have changed and what the physically appearance used to look like. To do this, scientists would use the specific parts of fossils, like bone shape and the markings from muscle to determine differences. It determined many things like how they interacted, held tools and that the brain has changed over

Fossils have very valuable information. As we study and understand fossils we can learn about the Earth’s history. In this process we learn about the organisms that have lived and continue to live on this Earth. We can learn so much about the past. We can make discoveries about diseases and past climate changes and how it can affect us in the present.

Mutations are caused by errors in DNA replication or repairs, or chemical or radiation damage

“An organism's genotype is the collection of genetic variants it possesses. Its phenotype, by contrast, is its traits -- visible features of the organism like eye color, hair color, height and so on. Some traits can be affected by environmental factors” (Brennan). Cells copy their DNA when they divide and both daughter cells inherit an identical copy. Your genes carry the instructions for the growth and development of your body. However, your phenotype is influenced during embryonic development. For example, if you're malnourished as a child, your height at adulthood may be shorter than what you would predict based on your genes alone. Consequently, there can be more than one phenotype for the same genotype. Natural selection acts on phenotypes, so it only acts on the genotype indirectly. Phenotypes are driven by DNA because they represent the genetic makeup, the genotype. Phenotypes are the observable features of the genotype that is

Genetic variation is used to explain the change in the makeup of the DNA sequence. Additionally, Genetic variation is what makes every individual distinctive and unique in their own way. Also, whether in terms of hair color, skin color or even the shape of our faces is described as genetic variation.

To this day scientists have discovered four members from this group of primates that were believed to be the earliest primates to begin walking upright. The next group up the tree is Australopithecus group of four members. These were the earliest group of primates that began walking upright more so for longer periods, but still spent time in trees. This is the group that Lucy belonged to, which occupied Africa from about 4 million to 2 million years ago. The next group up the tree is Paranthropus, which had three members. This is the group that the newly discovered LD 350-1 fossil belongs to. This group was characterized by large teeth to eat a wide variety of food. This group is believed to have walked the earth between 1-3 million years ago. The last group at the top of the tree is the homo. This group appeared on earth at about 2.8 million years ago. This is our group. Homo sapiens is the scientific classification for modern humans (“Human Family Tree”). It should be noted that like other animals there were probably many more members of each group. However, paleoanthropologists can only guess the amount and how they fit to us, at least until more fossils are

Genotype is the genes that we inherit from our parents also known as our DNA. DNA is composed of four nucleotides known as adenine (A), thymine (T), guanine (G), and cytosine (C). Each nucleotide has a complementary pair, which afterwards encodes certain information, adenine’s complimentary pair is thymine, and cytosine’s complimentary pair is guanine. As stated by Ed Green in the NOVA What Makes Us Human, “The order of the nucleotide encodes the information. In human DNA, the way these four molecules line up over 3 billion times determines who we are.” Depending on how these genes line up and how they transcribe into proteins is how we obtain our characteristics. These molecules are part of the reason why we posses the same genome for a trait, yet the appearance of the trait is different. For example, my friend and

The significance of this subtlety in our genetic differences could be interpreted in a couple of different ways. On the one hand, perhaps this is merely an indication of complexity and we are distinctly different, only we do not yet understand what genes play this defining role or in what way. On the other hand, what seems more likely to