![]() ![]() It is unclear what precipitated the tremendous population growth associated with this second occupation of the Near East and subsequent dispersal ( 7) possibly, cultural advances accumulated to a “tipping point” that supported extreme demographic growth ( 8), or anatomical changes that are not reflected in the paleoanthropological record occurred in the ancestral population. Only after this point do anatomically and behaviorally modern human remains become widespread in Eurasia. It is not until at least 50,000 y ago that evidence of behaviorally modern humans occurs in the archaeological record in the Near East. However, current evidence indicates that this near-modern population did not persist in the Near East and was subsequently replaced by Neanderthals during the following glacial period, with little evidence of temporal overlap ( 5, 6). It is clear that anatomically near-modern humans occupied the Levant ( 4) during a warm interglacial period 130 to 80 kya, when this region was ecologically similar to northeastern Africa ( 5). It is important first to distinguish between the presence of early near-modern humans in the Near East and the very distinct OOA exit associated with the Great Expansion. ![]() How do we reconcile this major demic expansion with the population stability that followed for thousands years until the inventions of agriculture? We review advances in understanding the genetic diversity within Africa and the great human expansion out of Africa and offer hypotheses that can help to establish a more synthetic view of modern human evolution. It should be appreciated that the initial expansion and subsequent serial founder effect were determined by demographic and sociocultural factors associated with hunter-gatherer populations. These two patterns are relevant for medical genetic studies mapping genotypes to phenotypes and for inferring the power of natural selection in human history. This particular population history gave rise to the two defining features of genetic variation in humans: genomes from the substructured populations of Africa retain an exceptional number of unique variants, and there is a dramatic reduction in genetic diversity within populations living outside of Africa. Genomic data from contemporary humans suggest that this expansion was accompanied by a continuous loss of genetic diversity, a result of what is called the “serial founder effect.” In addition to genomic data, the serial founder effect model is now supported by the genetics of human parasites, morphology, and linguistics. Educators are free to pick and choose what topics to cover, and how deeply to pursue these topics.Genetic and paleoanthropological evidence is in accord that today’s human population is the result of a great demic (demographic and geographic) expansion that began approximately 45,000 to 60,000 y ago in Africa and rapidly resulted in human occupation of almost all of the Earth’s habitable regions. Ergo, we are able to offer items on topics not always (or ever) covered in any great depth in high school classes. We are not bound by what can be contained within a physical textbook. Our materials are thus limited in sequence (yet cover all of American history), while not being limited in scope. But of course, the civil rights movement had its beginnings long before 1960. For example, the "Decades of Change" unit (1960-1980) looks at the social and political upheavals of the 1960s, with spilled over into the 1970s. Following traditional practices, our materials are arranged chronologically, with some allowances made by topic. Standard high school courses textbooks limit the scope and sequence of this curriculum. These free United States History course materials are designed for junior (grades 7-8) and senior (grades 9-12) high school students. Unit 15: Bridge to the Twenty-first CenturyĬlick here for our collection of general Social Studies printables that can be used in different classes, including United States History-American Studies. Unit 14: New Conservatism and a New World Order Unit 5: Westward Expansion and Regional Differences Unit 4: Formation of a National Government These also contain links to materials for elementary school students. You can find even more materials to supplement your lessons by clicking on Social Studies or Geography. ![]() Our American History course materials for junior and senior high school students and teachers are divided into twenty units. They contain everything from outlines, to puzzle worksheets, to lesson plans, to complete projects with grading rubrics. Outlines, PowerPoints, Lesson Plans, Worksheets, Maps, and More ![]()
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