The gradual change in human structure, genetic composition, and anatomy over a period of time is called human evolution. The process of evolution dates back to six million years ago when the ancestors of modern human beings underwent simultaneous and gradual body changes. These changes were passed from one generation to another coupled with modifications. Modifications in genetic structure come by as a result of adaptations. Organisms usually undergo adaptations to help them reproduce or survive certain conditions in their habitat. Individuals inherit the most desirable characteristics from their ancestors that enable them survive and reproduce successfully. Those who fail to inherit desirable genes and consequently fail to adapt would die (Ruse p.17).
Evolution timeline Sustnrs (N.P)
The Common Ancestor
Fossils discovered by scientists over the years are proof of human evolution. Not all living organisms have fossil records because there are conditions that must exist for fossils to be formed. Anthropologists believe that the common ancestor of the human race existed about five to eight million years ago. The two species emerged to form two different lineages. The first lineage evolved into chimpanzees and gorillas while the other evolved into hominids or the early humans. For the million years that followed, manifold humanlike creatures came into existence. These creatures have been reflected in fossil records and are said to be close relatives but not necessarily the ancestors of present generation human beings.
Some scientists have faulted fossil records for not giving the correct line of ancestry. There believes that a number of the hominids were wiped out and left no lineage at all. However, the rest of the hominids may have a direct relationship with the Homo sapiens or modern humans. The exact number of hominids that existed cannot be told but the discovery of new fossils from time to time makes human evolution clearer than before.
The evolving human head (Human Evolution timeline, n.p)
Areas of fossil discovery
Australopithecus
Fossils of this apelike species were first found in South Africa. Its skeletal structure and characteristics are quite different from the apes. It had small canines which are significantly different from long canines that most primates have. The Australopithecus also used two legs as a primary way of locomotion. Fossil records show that this species evolved six million years ago. Several fossils of the Australopithecus have been discovered in Chad, Ethiopia, Kenya and Tanzania (Ruse p.20-24).
Rate of brain development
The Homo Genus
This species is said to have evolved two million years ago. The difference between the Homo genus and Australopithecus is their large brain. Another species of the Homo called Homo habilis resembled the Australopithecus in many ways except for their distinctively smaller teeth and hands that looked like the modern man’s hand. Another Homo species called Homo erectus also had similarities with the modern humans. Fossils of Homo erectus were found in Asia, Europe and Africa. Their brains were relatively smaller than the modern human’s brain. The final evolution is said to have happened two-hundred thousand years ago. The transition is said to have been from the Homos to the modern age humans. The late Homo species like the Homo sapiens and Neanderthals evolved complex and large brains leading to developed culture, language and other aspects of human life (Ruse p. 31-34).
Homo sapiens
Scientists believe that this species entails the modern age humans. There fossils have been dated to one hundred years ago. The Homo sapiens species is said to undergo cultural evolution and not biological evolution.
Height of early man
The evolving man, timeline. (Human Evolution Timeline, n.p)
Works Cited
"Human Evolution Timeline". Human Evolution Timeline. N.p., 2016. Web. 20 June 2016.
Ruse, Michael. The Philosophy of Human Evolution. Cambridge: Cambridge University Press, 2012. Print.
Sustnrs. "Mass Extinctions And Mass Evolution: Speaking At Ignite Chicago". Sustnrs. N.p., 2013. Web. 20 June 2016.
