Debate on Single Origin Vs. Multi-regional Origin Theories

Essay by ladyace63A+, November 2006

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The theory I lean towards is the multi-regional theory because with fossil evidence they now use molecular evidence which shows Africa was not the sole source of modern human DNA. The molecular evidence uses mitochondrial DNA to reconstruct our heritage and ancestors relationship to apes and baboons. The evidence that swayed my decision is the multi-regional hypothesis which showed a model for the modern human origin through matched transition from Homo erectus to modern Homo sapiens with links among these populations through gene studies. Because mitochondrial DNA in inherited it can be used to study the increase of mutations to establish evolutionary relationships through molecular clocks. The human species holds that some or all of the genetic variation between the contemporary human races is attributable to genetic inheritance from either the Homo sapiens subspecies, or even other hominid species, that were dispersed geographically throughout Asia, Europe, and Australasia, prior to modern evolution of modern Homo sapiens, which dates back to at least 70,000 to 150,000 years ago.

The sources for genetic variation in modern Homo sapiens include Homo neanderthatlensis and Peking Man which is a subspecies of Homo erectus. This view contrasts with the single origin hypothesis which states that modern Homo sapiens evolved from a single geographically localized ancestral hominid population whose descendants replaced all other species of hominids over the course of tens of thousands of years without interbreeding or subspecies. The multi-regional hypothesis was originally developed from the fossil evidence but more recent work has focused on molecular data in which DNA is put into chronicle order. Work has been done with non-recombining DNA such as mitochondrial DNA and the Y chromosome. In 2001 a team of Chinese scientists wrote all Y-chromosome samples in China were originally derived from an ancestry of African origin. In Asia, US,