Mitochondrial Eve was: a. fossil evidence of the Biblical Eve. b. an mtDNA sequence that could have given rise, by mutation, to all modern human mtDNA. c. a hominid who had features of both australopithecines and Homo. d. a Neanderthal who mated with a Cro-Magnon to produce the first anatomically modern humans.
The correct answer and explanation is:
Correct Answer:
b. an mtDNA sequence that could have given rise, by mutation, to all modern human mtDNA.
Explanation:
Mitochondrial Eve is a term used in genetics to describe the most recent common matrilineal ancestor of all modern humans. This woman is not a specific fossil or biblical figure, but rather a theoretical individual whose mitochondrial DNA (mtDNA) has been passed down, through mothers only, to all living humans today.
Mitochondria are the energy-producing structures within cells, and they have their own DNA, separate from nuclear DNA. Importantly, mitochondrial DNA is inherited solely from the mother, without recombination from the father. This allows scientists to trace maternal lineages far back in time.
Mitochondrial Eve lived approximately 150,000 to 200,000 years ago in Africa. She was not the only woman alive at the time, nor the only one with descendants today—but her mtDNA is the only lineage that has survived unbroken to the present. Other maternal lines either ended due to lack of female offspring or other evolutionary bottlenecks.
Scientists used comparative mtDNA analysis from people around the world to reconstruct this lineage. All modern human mtDNA sequences can be traced back to a single ancestral sequence—Mitochondrial Eve’s—making answer (b) correct.
Importantly, this concept does not suggest that she was the first human or the only human alive at the time. Also, the term should not be confused with the biblical Eve or interpreted as direct fossil evidence, ruling out option (a). She was also not a Neanderthal or a hybrid of Neanderthal and Cro-Magnon (which eliminates d), and she was not a transitional fossil between australopithecines and Homo (which rules out c).
In conclusion, Mitochondrial Eve represents a genetic ancestor identified through mtDNA, not a specific fossil or religious figure, and her lineage is key to understanding human maternal ancestry.