Why do researchers studying the migration history of the human population use mitochondrial DNA (mtDNA)to trace migration patterns?

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Researchers studying the migration history of the human population use mitochondrial DNA (mtDNA)to trace migration patterns.Whereas the zygote receives chromosomes from both parents,the organelles,such as mitochondria,are usually inherited only from the egg because it contains so much more cytoplasm than a sperm.In other words,you received mtDNA only from your mother,who received it from her mother,and so forth to an original ancestor.This process of inheriting mtDNA is called maternal inheritance because it assumes that fathers had nothing to do with it.mtDNA,like nuclear DNA,is subject to occasional harmless mutations.After several generations,a particular mutation is present in almost all the men and women where it arose.When people leave a region,they carry the mutation with them.Therefore,by tracing mutations from one locale to another,researchers have determined migration patterns.To understand why mtDNA studies are appropriate,imagine small groups of colonists migrating out of the main population in Africa and establishing new populations in these other areas.The colonist populations would be expected to have only a small sample of the genetic variation present in their original source population.Geneticists refer to this as a founder effect.As the populations migrated farther from their source population,no exchange of genetic variation (gene flow)took place between the old and new populations.Over time,the new colonist populations can be genetically differentiated from the original source population because of newly acquired mutations in their mtDNA.

Why Do Researchers Studying the Migration History of the Human