Original transcription : http://www.wellcometreeoflife.org/transcript/
Video : http://www.wellcometreeoflife.org/
Click here to listen to my record
The extract that I record :
So, a hundred and fifty years after the publication of Darwin’s revolutionary book, modern genetics has confirmed its fundamental truth. All life is related. And it enables us to construct with confidence the complex tree that represents the history of life. It began in the sea, some three thousand million years ago. Complex chemical molecules began to clump together to form microscopic blobs: cells.
These were the seeds from which the tree of life developed.
They were able to split, replicating themselves – as bacteria do. And as time passed they diversified into different groups. Some remained attached to one another so that they formed chains. We know them today as algae. Others formed hollow balls which collapsed upon themselves, creating a body with an internal cavity. They were the first multi-celled organisms. Sponges are their direct descendants.
As more variations appeared the tree of life grew and became more diverse. Some organisms became more mobile and developed a mouth that opened into a gut. Others had bodies stiffened by an internal rod. They, understandably, developed sense organs around their front end.
A related group had bodies that were divided into segments with little projections on either side that helped them to move around on the sea floor. Some of these segmented creatures developed hard protective skins which gave their bodies some rigidity. So now, the seas were filled with a great variety of animals.
And then around 450 million years ago some of these armoured creatures crawled up out of the water and ventured on to the land.
260 words and 2min33
