人は皆、先祖を辿ると約20万年前の１人のアフリカ女性に行き着くといわれ、彼女は「ミトコンドリア・イブ」と呼ばれている。これは、英国・オックスフォード大学のブライアン・サイクス教授の仮説に基づくもの。生物の体を形成する細胞中には、エネルギー生成の場である「ミトコンドリア」が存在するが、このミトコンドリアは母親の卵子から子供に受け継がれる。「ということは、ミトコンドリア中のＤＮＡ(遺伝子)を分析すると、過去へ母系をたどっていくことができるのではないか？こう仮定すると、現代人は全て約20万年前のアフリカ女性の子孫に辿り着く」…この仮説を教授は1987年に発表したのだった。

先月英国で発売された本『The Seven Daughters of Eve』(イブの7人の娘達)に、サイクス教授はこれまでの研究結果をまとめている。これによると、現代人のミトコンドリアＤＮＡの系統のうち、３４系統が連続しているという。つまり、現代人の源流を、「ミトコンドリア・イブ」の「子･孫」３４人の娘まで追い詰めたことになる。特にヨーロッパ系ヒトの祖先は7つの遺伝子系統に分類できるという…すなわち、全てのヨーロッパ人は7人の娘達の子孫、ということになる。

なお、教授は「自分のイブが誰なのか」という一般からの調査依頼を有料で請け負っている。既に数千人の人から依頼があったとか。

The Seven Daughters of Eve -- Book Review

The Seven Daughters of Eve makes a compelling read, one neither too light or too heavy on the techinical aspects of DNA profiling, more specifically, Mitochondrial DNA analysis. Through years of research and trial-and-error, the author and his research team have clarified several century-old debates, and their latest discovery-- that the majority of the European population can be traced back to seven individual women, who lived as long ago as 45,000 years-- is astounding.

THE SEVEN DAUGHTERS OF EVE by: Bryan Sykes (2001)

Although a large part of this book is actually involved in the leading-up to the Seven Daughters, it is justified with prior discoveries necessary to grasp the reality of the Seven Daughters discovery.

Did you know that all of the modern day pet guinea pigs originated with one blonde haired guinea pig a long, long time ago. Yes, it is true. The mitochondrial DNA does not lie.

Mitochondrial DNA is only helpful for tracing Maternal contributions to offspring, as the Mitochondria DNA is ONLY inherited from the mother (not diluted with the father's DNA, like most other DNA). Also, Mitochondrial DNA has a very slow mutation rate, and by using this rate, it is a simple matter to calculate how long ago the orginal woman existed, simply by comparing samples that are relevently close in sequence and counting the number of mutations. Multiply the number of mutations by the standard number and poof!!! -- You have the time frame of the original female.

Another mystery covered in this book was the argument between KON-TIKI author, Thor Heyerdahl, and his opposers. Heyerdahl had one theory of how the Polynesian Island became inhabited (that wanderes from the west coast of North American and South America braved the Pacific Ocean, just like is chronicalled in KON-TIKI) while his oposers asserted that the Polynesian Islands became inhabitated from Asia's coast line. This book, and it's author, proved once and for all, who was right.

Mitochondrial DNA was also used to identify the bodies of the last Tsar of Russia (and his family) by comparing the DNA extracted from the newly discover remains and comparing them to know descendants of the Royal Family slain so long ago. Imagine the author's surprise when he later discovered that HE was in fact, a distant decendant of the Tsar of Russia! (See, it goes to show that you never know what your family tree really holds!)

Also making appearances in THE SEVEN DAUGHTERS OF EVE are 'Chedder Man' and 'Ice Man', as well as other ancient treasures unearthed and preserved, only to lend a bit of thier mitochondrial DNA to Sykes and his team.

The Seven Daughters of Eve devotes a chapter to each of the women: Ursula, Tara, Helena, Katrine, Xenia, Jasmine and Velda. Sykes even goes so far as to construct a hypothetical 'day in the life' saga for each women, which lets the reader imagine how the women lived, survived and influence the social and economical evolution of modern man (and woman).

I thoughoughly enjoyed reading this book, as it is suited for the common layperson(non-scientist) and professionals alike. It allows the reader to scrutinize the world of genetics, ancestry and experimental science.

One thing I was left wonder, though, is just which of the women is my direct decendant? And just how expensive would it be to find out?

For more on the subjects of genetical history, try these:

This content was written by Karen Pruitt Fowler. If you wish to use this content in any manner, you need written permission. Contact Karen Pruitt Fowler for details.