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 survive in a strange world, with elements of "Nintendogs". The mobile phone version of "Spore", called "Spore Origins", was based on the tide pool phase, in which players try to survive as a multicellular organism, with gameplay similar to "flOw". On March 6, 2008, an iPhone version was demonstrated at Apple's iPhone SDK press event, though there was no commitment to ship such a product given at that event. The iPhone-Spore demo made use of the device's touch capabilities and 3-axis accelerometer. Electronic Arts confirmed on March 31, 2008 that "Spore" would be receiving post-release expansion packs. Only one expansion