About 150 years ago, Charles Darwin wrote a book where he described his theory of the tree of life and natural selection. He invoked the idea that all living creatures are linked through millions of years of evolution.
The affinities of all the beings of the same class have sometimes been represented by a great tree…As buds give rise by growth to fresh buds, and these, if vigorous, branch out and overtop on all sides many a feebler branch, so by generation I believe it has been with the great Tree of Life, which fills with its dead and broken branches the crust of the earth, and covers the surface with its ever branching and beautiful ramifications.
This theory has since been thoroughly tested and verified by a wide range of evidence, especially since the discovery of genetics.
The Tree of Life is a way of imagining the historical process of evolution. The video above not only visualises the concept, but simplifies it with the help of Sir David Attenborough.
When you’ve watched the video, you can explore the Tree of Life further by viewing an excellent, interactive 3D guide from the Wellcome Trust. There’s also educational material available, such as teacher notes and student worksheets.