(根据维基百科)[1],“所有已知类型的生物能够一定程度的对刺激的回应,繁殖,生长和发育和通过体内平衡自律。”Further, watching a video like the "[Earth Breathes as Seasons Change][2]" ([which is from NASA][3]) - superficially gives the sense that the "Earth is alive" so to speak. **Is Earth an organism?** Since there is no unequivocal definition of life, the current understanding is descriptive. To define Earth as an organism, your answer most show either via observed phenomena or theoretically observable phenomena that Earth exhibits all or most of the following traits: [Homeostasis, Organization, Metabolism, Growth, Adaptation, Response to stimuli, and Reproduction][4]. [1]: http://en.wikipedia.org/wiki/Organism [2]: http://www.youtube.com/watch?v=kSNbLYHRrU8 [3]: http://www.nasa.gov/vision/earth/features/blue_marble.html [4]: https://en.wikipedia.org/wiki/Life#Biology [5]: http://www.popsci.com/science/article/2013-02/physicists-create-nearly-living-crystals [6]: http://biology.stackexchange.com/questions/17030/how-does-physics-impact-the-classification-of-organisms