It is incredible, and it is incredibly hard to believe too, because although we've changed so much, we don't actually see any of those changes happening. Generation after generation, we just look the same. The problem is one of time. The periods over which even tiny changes happen are so long that almost beyond our imagination. But to make sense of those time periods, to see them in some perspective, I've brought you here to a cave deep in the French Pyrenees.

In the middle of the last century, a bookseller from a nearby town of Tuluz, used to visit this cave. And as a hobby, he dug around for bones and evidence of prehistoric remains. And he did this for some 40 years. And then late in the afternoon, on June the 11th, 1905, having been digging all day, he prepared to go but chose to go by a different route. And as he left, he was passing this wall and something caught his eye. He lifted up his lamp and this is what he saw--stencils of human hands from nearly 30,000 years ago. They are amongst the oldest images made by human beings on the planet. They are 6 times older than the Pyramids in Egypt and 8 times older than Stonehenge. Quite what they signified to the people who made them, no one knows. They were a Stone Age people and they came here at the coldest part of a last Ice Age. And over here are the most interesting images of all.

It is thought that these stencils here were made by someone no bigger than a toddler, a child in a primitive world, the son or daughter of somebody who you would think of as a caveman. And yet if I had taken such a child and brought it up as a baby in my own house, it would be indistinguishable from one of my own children.

Because by the time these people pressed their hands against these walls, all the changes which make us what we are had already happened. The evolution of the human body was, to all intents and purposes, complete. If this child were to be raised with my own children, it would look the same, it would talk the same, it would play the same computer games, and it would grow up wanting to be a doctor, a footballer, or maybe even an astronaut.

words and expressions

Pyrenees: 比利牛斯山脈：歐洲西南部山脈，從比斯開(kāi)灣沿著法國(guó)與西班牙邊境，到地中海在皮科·德·皮妮特，它高達(dá)3，406·2米(11，168英尺）

stencil:The lettering or design produced with such a sheet.
圖案，文字：用模板或蠟紙復(fù)制出的字形或圖案

toddler:One who toddles, especially a young child learning to walk.
蹣跚行走的人：一個(gè)蹣跚行走的人，尤指一個(gè)剛學(xué)習(xí)走路的幼兒

indistinguishable:（常與from連用）不能區(qū)別的；不能辨別的
"The synthetic material is indistinguishable from real silk, but much cheaper."
"這種合成衣料與真絲難以區(qū)別,但便宜得多。"

to all intents and purposes:實(shí)際上