Final answer:
The Eve theory posits that all humans can trace their maternal ancestry back to a single woman, mitochondrial Eve, based on the study of mitochondrial DNA (mtDNA), which is passed down maternally. This theory is supported by molecular evidence that uses mutational patterns in mtDNA to construct a genetic timeline and branches of the human family tree. Mitochondrial DNA mutates at a set rate and provides insights into our ancestral lineage and evolutionary history.
Step-by-step explanation:
What is the Eve Theory?
The Eve theory, also referred to as the mitochondrial Eve theory, is the hypothesis that all living humans can trace their maternal ancestry back to one woman, termed mitochondrial Eve, who is believed to have lived in Africa around 200,000 years ago. This theory is based on the study of mitochondrial DNA (mtDNA), which is inherited exclusively through the maternal line. Unlike nuclear DNA, mtDNA is passed down from mothers to their children without recombination, which makes it a valuable tool for tracing lineage over generations.
Researchers have found that mutations in mtDNA occur at regular intervals, allowing them to construct a genetic timeline. These mutational patterns have helped map out different branches of the human family tree originating from the mitochondrial Eve. Even though not everyone's mtDNA today matches that of the ancestral Eve exactly, due to the spontaneous mutations over time, all present mtDNA lineages ultimately lead back to this common ancestor.