Natural selection is the process by which organisms that are well tailored to the environment have the ability to continue to exist and to pass on their hereditary traits the next generation. On other hand, organisms that are less adapted tend to suffer natural elimination. In this case, environment is defined in terms of both physical factors (flood, famine, drought etc) and biological factors (predation, diseases, and competition). A good example is the long-necked giraffe which are chosen by nature based on their height which enables them to reach high leaves. However, the short-necked giraffes cannot reach high leaves and therefore suffers eradication due to starvation. Artificial selection is caused by human beings. In this case, individual chooses the traits that they desire and eradicate the unwanted traits. For examples, farmers chose to breed more fat cows because they have more meat. The end result is that the skinnier cows reduce to the level of extinction. This basically occurs in the case of domestication of both plant and animal species.
The similarity between the two types of selections is that they both produce in an organism after a period of time. However, in natural selection, the selection forces are the environment while human beings rise as agents of change in artificial selection. In other words, the process of artificial selection is anthropogenic. That is, human interferes with the natural system of the environment so as to produce their desired traits. The process of natural selection, on the other hand, occurs through sexual reproduction in which the hereditary traits that are transmitted to the next generation are determined by the principle of survival for the fittest.
Question 2
Paleo-anthropology is the study of prehistoric humans by virtue of combining two major disciplines; physical anthropology and paleontology. Since it is not possible for scientists to unveil the pages of history and literally observe the ancients humans. They often utilize other alternative sources of evidence to support their claims. They employ various aspects of the human past to explain the origin of man. Their main emphasis lies on the cultural and the biological dimensions of the ancient human beings. Paleo-anthropologist are similar to the archeologist since they depend on evidence from excavation sites, the fossil bones of the human ancestors, artifacts, the context in which human remains were discovered. This work is often tasking but the paleo-anthropologists have given themselves for the task. This is because the forces of nature tend to destroy older items. Hence, it is true that some of the important historical evidences have been destroyed by forces of nature.
Paleo-anthropologists have the daunting task of searching the traces of history that have not vanished. In other words, they use the clues to infer the meaning. The data of paleo-anthropology is drawn from paleontology, archeology, and geology each of which provides vital information in the understanding of human evolution and history. For instance, a group of students from Arizona University discovered a juvenile skeleton which was 3.3 million years old. From this they were able to hypothesize the cultural developments as well as the evolution of humans. Geology studies the history of the earth based on the sedimentary deposits. They assists the paleo-anthropolgists by identifying the environments where the fossils as excavated. Paleontology focuses on the fossils which are traces of past such as human remains in volcanic ash, footprints of dinosaurs as well as bone of mammals. Archeology studies the tools used by the ancient humans so as to understand the cultural developments of man.
Question 3
Hominid evolution studies the subgroup of species known as Homo sapiens which includes the humans and their immediate ancestors. The bones of various hominids give an understanding of the anatomical similarities which are vital in the study of human evolution. Various non-human primates that were discovered 3 million years ago displayed bipedal locomotion as that of humans. That is their pelvic bones and hip region were similar to those of ancient humans. The foot and the leg bones were also similar to those of human beings than those of apes. The aspect of bi-pedalism is vital in the study of hominid evolution. As a matter of fact, the early hominins had longer legs than arms. This was basically for maintaining an upright posture. Their hands were also adapted to carrying objects such as tools.
The chimpanzees and the apes do have elongated arms than legs. Their feet lack the arches are found on the bottom of human feet. They also have big toes which are not typical of humans. These provide a clue that the apes and chimpanzees might be sharing the same ancestral origin. The late australopithecines share similar anatomically beneath their neck but they head differs with regard to various features. The study of non-human primates provides a special insight into the understanding of the nature of human conduct.
The study of non-human primates also explores the degree to which the some cognitive accomplishments of human are exceptional and that such achievements may not be possible for other species to realize. For instance, a Nobel-Prize winner, Tinbergen argued that to understand human behavior, scientists must employ four diverse levels of analysis which included the development of non-human primates.
Question 4
Evolution involves changes from different scales ranging from small increase in scale to large changes in a generation. These levels as categorized into two groups namely micro-evolution and macro evolution. Micro-evolution is defined as the change in the frequency of a gene within a population. Such changes are often observable within a short span of time. That is, from one generation to the next. In other words, microevolution examines the genetic variations over a small number of generations within a given population. These changes are often caused by the process of natural selection, gene mutation, gene drift and gene flow.
Macroevolution entails large scale trends, patterns, and the speed of revolutionization among different groups of species as well as families. Microevolution and macroevolution differ in that macroevolution emphasize on the changes that happen above the level of species while microevolution focus on the evolutionary changes that occur within the species in a population.
Macroevolution encompasses million of years. Macroevolution has created difficulties to many historians who claim that there is a limit within change cannot occur. The lack of evidential transitional forms within a species also discredits macroevolution. Creationist cites that different numbers of chromosomes in a species do not permit macroevolution to take place. Scientists who are opposed to the theory of evolution argue that it is tautology. That is, it a hypothesis which cannot be tested. However, some specific claims of macroevolution can be tested like any other hypothesis. For instance, it is possible to prove whether weasels are more strongly interrelated to red pandas as compared to bears. This test proves the historical construction of species. Macroevolution has proved to be the only way in which humanity have developed their diversity.
5- Define three general trends of hominid evolution and explain how these trends interacted over time.
Trends are common in all aspects of life. The three major trends of hominid evolution are; bipedal, evolutionary dead-ends, and tool use.
Bipedalism is a characteristic which distinguishes humans in the primate world. In other words, human walk on two legs and not four like in the case of other primate and non-human primates. This is believed to have evolved from a rigid-legged quadrupedalism in their ancestors to into rigid-legged bipedalism. Ardipithecus and Australopithecus are the earliest known primates who used two feet instead of four. They lived between 3 and 4 million years ago. Their home was mainly forested areas but they later moved to open grasslands. It is believed that they eventually evolved to be modern humans.
The second trend involves the use of tool and technology. It is this trend that drew a distinction between humans and the early hominids. The first ancient tool was found in Africa and it was known as Olduwan tool. It was then followed by Acheulean tools which were also discovered from Africa. Homo sapiens then proceeded to be greatly involved in tool use. This was the main reason why Homo sapiens survived while the Neanderthals suffered extinction.
The third trend is the evolutionary dead-ends. This entailed the extinction of less adaptable species and improvement of the species that survived. This trend advocates that species should be viewed holistically so as to be able to understand which species precedes or follows other species. In the modern society, human walk upright and employs tools to improve their daily life. It is also important to note humans have evolved into one holistic branch which is responsible for controlling his environment.
Question 6
Many paleo-anthropologists disagree on how to classify some fossil in the taxonomical record because they lack more information in regard to their age. As a result the field is often marred with forgery which is not a good example of science. For example, when Hesperopithecus and Piltdown man were discovered, it was hard to find a place for them in taxonomical records.
Another reason why the face such difficulty is based on the fact that conclusions are sometime drawn from a personal view and scientific evidence. The human fossils are very sparse. This means that paleo-anthropologists draw their conclusion by perusing from one perilous deduction to another with a hope that the next discovery shall not disqualify their conclusions. A good example is the discovery of hobbit bones which was believed that it’s not a fossil but rather a pygmy. The process of making a mold to make copies of bones which tend to damage the bones until they loss their anatomical details. It therefore becomes very difficult to record such findings. Some paleo-anthropologists have also been marred with cases of hoarding their findings for some time with a fear of piracy from their colleagues. The result is that such findings get damaged and thus cannot be adequately classified in the taxonomical records. For instance, in 2005, there was a discovery of identical jawbones.
Such practices are not good in science. As a matter of fact paleo-anthropology have recently been marked as an non-exacting science. Forgery and new discovery often forces a lot of changes in the paleo-anthropology. This makes people to doubt the eligibility of their taxonomical records.
Question 7
The four major forces of evolution include genetic flow, mutation, genetic drift and natural selection.
Natural selection occurs when organisms that are finely adapted to the environment continues to survive and pass on their heritable traits the next generation. Organisms that are not finely adapted tend to suffer natural elimination. For example, the long-necked giraffe are chosen by nature based on their height which enables them to reach high leaves. However, the short-necked giraffes cannot reach high leaves and therefore suffers eradication due to starvation. Natural selection ultimately changes the allele’s frequencies in a species.
Mutation is the drastic change in the DNA of an organism. Even though mutations are harmful, a small degree of it may endow an organism with unique trait for survival, either by helping in mating, escaping predators, or getting food. When such unique traits are passed on to the next generations, the generation rises to be different from their original ancestry.
Genetic flow refers to the transfer of genes between populations due to migration. Small extents of migration allow the population to diverge, whereas large scale migration or immigration increases the similarities between neighboring populations.
Genetic drift is defined as an overtime change in allele frequencies due to chance and chance only. For instance, consider a population of 10 individuals which experiences a change if allele A over a period of time. Assume that the frequency of change in allele A is .50 and that of another allele a is .50. This implies that population 10 persons will have 20 alleles equally spread between the two alleles. The possibility of transmitting alleles to the next generation is halfed. Therefore, a change in allele frequency caused by chance affects the possibility of transmitting such traits to the next generation.
Question 8
The ‘Minds Big Bang’ is associated with emergence of creativity in Homo sapiens. This concept brings into light the intellectual capacity of humans that have made them to manipulate the environment for their good. The wiring in the brain cells of humans helps to produce intelligence.
For instance, the mind of a child at the age of five is capable of getting to understand people’s minds. This is contrary with chimpanzees at the same age.
Another important aspect of ‘Minds Big Bang’ concept relates to the diverse languages in the world. Each language follows certain constraints and rules known as syntax. This enables human to adequately arrange information. The chimpanzees are incapable of organizing information even after subjection to training. The language dispensation is a unique trait in humans which makes it probable to use syntax in both sign and written language. Many
