As soon as I got to First Animal, I realized this was going to be a long story. I tried as hard as I could to keep it short, and began trying to end the story after spending a lot of time on the vertebrates' invasion of land. Continually, I was battling myself over what was important enough to go in and what could be mentioned briefly or cut out. The result is both a bit long and a bit thin, since there was a lot to cover. There is much that I have left out in my attempt at brevity, including the Cambrian explosion and extinction, most of Australia's history, and the birth of the Internet.
You might notice that I give a lot more time to plants than one might expect. Remember, this is the story of life, not just of humans. It is possible to imagine a biosphere made up entirely of plants; it is not possible to imagine one with only animals. I feel that as a civilization, we are a bit animal-centric, from the halls of biology departments to endangered species legislation. We would do well to remember that every living plant is just as alive as you or me, and every one of them has an evolutionary history just as intriguing.
I began The Story of Life with a water covered Earth, but I could have started earlier, at the Big Bang or at the formation of the Solar System. It seemed both poetic and biologically appropriate to start at the same place that many creation stories, including the Christian Genesis, begin.
Life began in the ocean, and so too do many origin myths.
Throughout my explorations into ancient creation stories, I have been fascinated by the fact that many stories get certain details right. For example, the general order of events in Genesis is essentially correct: water, land, plants, animals, humans. Same with the Popol Vuh and others. Rather than trying to create a perfect, scientifically verifiable account of life on this planet, I merely extended this idea, trying to make the order of events come close to our current approximation of the truth.
It is important to note that in no way is this story to be taken as literally true, or even as a completely accurate version of the truth as we know it today. Such a story would inevitably carry the characteristics of a textbook: heavy, difficult to read, and quickly obsolete.
I deliberately removed all scientific terminology.
Words like "Archaeopteryx" and "speciation" are neither poetic nor easy to remember as a child. Their presence in other attempts at this sort of story is jarring, pulling you out of the feeling and flow of the story. They sound too much like a textbook. Not only that, but the complexity of these terms is for the most part unnecessary. The concepts behind them can often be explained using more familiar words. Once these concepts are understood, they can be built upon later in the educational process.
My ultimate goal is to hear about a child who learns about the origin of photosynthesis in school and says "Oh yeah, that's just like Green Thing!"