PH 106 Lecture Notes - Lecture 30: Y Chromosome, Mendelian Inheritance, Molecular Clock
27 Apr 2016
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Document Summary
Every person has 2 parents, 4 grandparents, 8 great-grandparents, etc. - biological ancestry . Every individual has only two alleles for most genes. Therefore at any locus, the genetic contributions of only two grandparents, two great-grandparents, etc. are represented. Genetic ancestry isn"t the same as biological ancestry . Due to independent assortment of chromosomes and recombination between chromosomes, each human genome is a mish-mash of all its ancestors. The only chromosomes that are transmitted unchanged are the mitochondrial genome (maternally transmitted only) and the y chromosome (paternally only) mtdna. Mitochondrial genome- small circular chromosome present in mitochrondria. 37 genes for mitochrondrial proteins (other mt protein genes in nuclear genome) Tracing the mtdna lineage back in time should identify eve the mrca wrt mtdna. Mitochrondrial eve was a female living in africa about 200,000 years ago. Similarly, y chromosome mrca is an african man from about the same time, but not necessarily the mate of mitochrondrial eve.
