"线粒体夏娃 "是科学家给所有活着的人类的母系最近共同祖先的一个名字。 这意味着所有活着的人类都有来自她的线粒体DNA。 线粒体夏娃被认为是大约14万年前生活在非洲东部的一个女人。 这个概念不同于最近共同祖先--因为随着时间的推移，一个人的祖先数量会成倍增加，所有人类的最近共同祖先生活得更近，可能不到10万年。 但由于核DNA的性重组，今天每个活人与那个共同祖先只有一小部分共同遗传物质。

让科学家们知道线粒体夏娃大约生活在什么时候的测试是基于线粒体DNA，即在我们细胞的发电厂--体细胞中发现的小环状DNA。 线粒体DNA只与自己进行基因重组，这意味着它从母亲到后代保持相对稳定。 使它发生变化的唯一因素是突变，由于平均突变率是已知的，科学家可以估计不同人类（或动物）血统之间有多大关系，以及他们最近的共同祖先可能生活在什么时候。 当时间尺度比较短，以数十万年而不是数百万年为单位，这种估计往往更准确。 涉及数亿年的时间尺度通常被视为准确性低。

There are a few misconceptions associated with the concept of Mitochondrial Eve. This woman was not the only human living at the time -- since humans descended from other hominids incrementally, scientists have opined that there was no "Adam and Eve" -- no founding couple, and Mitochondrial Eve only represents the person that all living humans got their mitochondrial DNA from. Mitochondrial Eve was one female among tens or hundreds of thousands that lived in Africa at the time. Other females living at the time may have been the common ancestor of all humans alive today, but there exists at least one male in their ancestral line between then and today. Conversely, Mitochondrial Eve gave birth to a daughter that gave birth to another daughter, through thousands of generations until today, where the mitochondrial DNA is still passed on in a daughter-to-daughter format.