Mitochondrial DNA
Mitochondrial DNA (mtDNA) is maternal-only genetic material found in cell mitochondria, ideal for forensic analysis of hair or old bones where nuclear DNA is insufficient.
Mitochondrial DNA (mtDNA) is the small, circular genetic material found within the mitochondria of a cell, inherited exclusively from the mother. Unlike nuclear DNA, it is identical among all maternal relatives and is highly useful for analyzing samples with low nuclear DNA, such as hair shafts or old bones. First sequenced in the 1970s, it has become a standard tool in forensic science and evolutionary biology for tracing maternal lineages.
What this means in real life
A child inherits a mitochondrial mutation from their mother that impairs energy production in muscle cells, causing fatigue and weakness—a condition passed down through the maternal line only, never from the father.
What it isn’t
It is not the main genetic code that determines your traits; that is nuclear DNA. Mitochondrial DNA is a small, separate genome that codes only for proteins needed to produce cellular energy.
Commonly misused online
People often claim mitochondrial DNA proves matrilineal ancestry with perfect accuracy across thousands of years, but mutations and recombination mean it's useful for recent maternal lineage only, not deep evolutionary history.