The quote reflects the staggering reality of extinction, emphasizing that nearly all species that have existed on Earth are now extinct. Bill Bryson, in his book "A Short History of Nearly Everything," highlights the enormity of life's impermanence and the dramatic changes the planet has undergone over time. This statistic serves as a reminder of the fragility of life and the vast history that has shaped our world.

By stating that 99.99 percent of all species are no longer present, Bryson invites readers to consider the processes of evolution and extinction that have influenced the development of life on Earth. It encourages a deeper appreciation of the current biodiversity and the need for conservation in a world where so much has been lost.