Question

the model of human evolution and migration that is most strongly supported by DNA evidence from human populations Answer:

Answer 1

Replacement model or Recent african origin model is the dominant model of the geographic origin and early migration of anatomically modern humans,which is strongly supported by DNA evidence.In paleanthropology ,it depicts the recent african origin of modern humans,also called the out of africa theory,recent single origin hypothesis,replacement hypothesis or recent african origin model.It follows the early expansions of hominins out of africa,accomplished by homo erectus and then homo neanderthalensis.This model proposes that all modern non-african populations are substantially descended from populations of homosapiens that left africa that time.Human mitochondial DNA haplogroups were found in high proportions among the san of south africa and the sandawe of east africa.Haplogroups are descendants and are largely confined to africa.Results from mtDNA collected from aboriginal malaysians called orangasli indicate that the haplogroups share characteristics with original african groups about 85000 years ago,and share characteristics with sub-haplogroups found in coastal south-east asian regions,such as australasia,the indian subcontinent and throughout continental asia,which had dispersed and seperated from their african progenitor approximately 45000 years ago.A large study of coop found evidence for natural selection in autosomal DNA outside of africa.This study distinguishes non-african sweeps,west eurasian sweeps and east asian sweeps.Based on this evidence ,the study concluded that human poplations encountered novel selective pressures as they expanded out of africa.A 2014 study by gurdasini indicates that the higher genetic diversity in africa was further increased in some regions by relatively recent eurasian migrations affecting parts of africa.Another promosing route towards reconstructing human genetic genealogy is via the J C Virus,a type of human polyomavirus which is carried by 70-90 percent of humans and which is usually transmitted vertically from parents to offspring suggesting codivergence with human populations.For this reason JCV has been used as a genetic marker for human evolution and migration.