Pollen tube selfing such as stigma and anther mature at different times or are different lengths, which significantly contributes to increasing genetic diversity of the next generation. There is great variation in the rate of growth of pollen tubes and many studies have focused on signaling. The gene expression in the pollen grain has been identified as that of the gametophyte and not of the parental sporophyte, as it expresses its own unique mRNA and own enzymes. In the peach plant, the style environment in which the pollen tube grows through, provides nutrition for the tube's growth to the egg. Pollen tubes
Development of Spore pack has been revealed so far, called "galactic adventures" . It will include an adventure editor, as well as many new items and the ability for a player to go down to a planet's surface. On June 24, 2008, the "Spore: Galactic Edition" was announced. This special edition game is priced at $79.99, and includes a "Making of Spore" DVD video, a "How to Build a Better Being" DVD video, by National Geographic Channel (not included in all countries), a "The Art of Spore" hardback mini-book, a fold-out "Spore" poster and a 100-page Galactic Handbook. "Spore" extensively uses procedural generation,