The Evolution Of Humans: The Origin Of Modern Humans

In the Pleistocene Era, hominins have been expanded rapidly in terms of survival, such as availability of food resources, migrating and how they defend their territories. Then, this has been lead hominins to develop intelligence and create a wide variety of tools. However, there is no specific evidence or answer to, how did human beings evolve and where did they come from. Environmental conditions or pressures have been played importantly, that contributed to the selection of the genus Homo in Africa, Europe, Asia, Australia, and there is an anatomical evidence over the past one million years, culminating in our modern genome; leads to developing human cognition and explains why modern humans are the only ones who exists today. The history

There are two different models or theories regarding the origin of Homo sapiens or modern humans. The first model is known as the Multiregional model. According to Johanson, multiregional model states that after Homo erectus left Africa and dispersed to other parts of the world, it slowly develops into modern humans. He adds some following components of this model. He says that some level of gene flow between separated populations prevented speciation. The textbook shows that the appearance of modern humans resulted not from replacement of populations, but the transmission of alleles. The textbook also shows that this model did not suggest the later dispersal of a second hominin species from Africa. It clearly demonstrates that these modern humans originated in the context of gene flow. The second model is known as the replacement models or also called Out of Africa models. Out of Africa Model states that modern humans recently in Africa, migrated into Eurasia and replaced all populations by Homo erectus and its descendants according to Johanson. The textbook states that this model shows that modern humans did not interbreed with the early hominids. In addition, Johanson asserts that anatomical, archaeological and genetic evidence gives belief that these modern humans are a recent evolutionary phenomenon. Moreover, Johanson says that the best evidence or explanation for the origin of modern humans is the Out of Africa model that suggests a single, African origin for Homo