The most robust statistical examination to date of our species' genetic links to "mitochondrial Eve" -- the maternal ancestor of all living humans -- confirms that she lived about 200,000 years ago. The Rice University study was based on a side-by-side comparison of 10 human genetic models that each aim to determine when Eve lived using a very different set of assumptions about the way humans migrated, expanded and spread across Earth... "Our findings underscore the importance of taking into account the random nature of population processes like growth and extinction," said study co-author Marek Kimmel, professor of statistics at...