In 1859, charles darwin wrote, "the affinities of all the beings of the same class have sometimes been represented by a great 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." at the base of the evolutionary tree of all life is

The full statement is this: In 1859, Charles Darwin wrote, 'The At the based of the evolutionary tree of all life is AN ORGANISM THAT IS A COMMON ANCESTOR TO ALL LIVING ORGANISMS.

In biology, evolution has to do with gradual but constant changes in the overall form of living organism. Scientists believe that all life forms came from a common ancestor; it is through the process of evolution and natural selection that primitive life forms developed into higher forms of living organisms. In short, what the statement given in the question is trying to say is that ALL LIVING ORGANISMS ARE RELATED BECAUSE THEY HAVE A COMMON ROOT (A COMMON ANCESTOR).