Mitochondrial dna dating
Not according to the tale of migration uncovered by analysis of ancient DNA from chicken bones recovered in archaeological digs across the Pacific.
Mitochondria are specialized structures unique to the cells of animals, plants and fungi.
Estimating the chronology of population migrations throughout mankind's early history has always been problematic.
The most widely used genetic method works back to find the last common ancestor of any particular set of lineages using samples of mitochondrial DNA (mt DNA), but this method has recently been shown to be unreliable, throwing 20 years of research into doubt.
What we've done is work out a formula that corrects this effect so that we now have a reliable way of dating genetic lineages.
"This means that we can put a timescale on any part of the particular family tree, right back to humanity's last common maternal ancestor, known as 'Mitochondrial Eve', who lived some 200,000 years ago.
Says Ph D student Pedro Soares who devised the new method: "Natural selection's very gradual removal of harmful gene mutations in the mt DNA produces a time-dependent effect on how many mutations you see in the family tree.They also have specialized cellular components called organelles, each of which executes a specific task.Organelles such as the mitochondria, the rough endoplasmic reticulum and the golgi serve respectively to generate energy, synthesize proteins and package proteins for transport to different parts of the cell and beyond.“Mitochondria” derives from two Greek words: “mitos” meaning thread, and “chondros” meaning granule.As described by Karen Hales, a professor of biology at Davidson College, in Nature Education, these organelles are dynamic, and constantly fuse together to form chains, and then break apart.