The DNA found in mitochondria, the energy-producing organelles of cells, is often analyzed to trace evolutionary pathways. Mitochondrial DNA (mtDNA) has a high "substitution" or mutation rate, compared with other sites in our genome. mtDNA is transmitted only from mother to child, and can be inherited intact over thousands of generations. Mutations in the mtDNA sequence can be used to reconstruct the maternal lineage of populations.
Keywords:
mtdna sequence,organelles of cells,maternal lineage,maternal inheritance,mutation rate,mutations,pathways,dna,populations,generations
DNA found in the mitochondrion of a cell differs in structure and is separate from the DNA found in the cell nucleus. Mitochondrial DNA, or mtDNA, exists as a circular loop of double-stranded DNA rather than the linear form found in nuclear DNA. However,
This illustration shows the two major mitochondrial DNA lineages. The lower branch includes only African populations. The upper branch has both African and non-African members.
Mutations are the grist of evolution, and have accumulated in our DNA over time. When populations separate, each group accumulates their own unique set of DNA mutations.
When comparing Neandertal and human mtDNA, researchers found that the differences between the sequences put Neandertals outside the range of variation of modern humans.