Join discussions about this article in our Group on Facebook
Neither Part II or Part IV came in as part anything; they were just called "The Numbers Game" and "The Index Fossil". However, they saw how The Numbers Game, Part III and The Index Fossil made a complete thought.
Greg: "An index fossil is an extinct species that lasted for only a few million years. This is a very brief period of time by most species' standards. They are very useful for geologists because no matter where on the earth one is searching, if he finds a species that is a known index fossil then the age of the surrounding rock is immediately known. Mankind will make a perfect index fossil because we have only been around for about 2 million years. We could still persist for another few hundred thousand years and still be considered a great index fossil".