The answer to this question would not only fill one of the largest gaps in scientists' understanding of nature, but also would have important implications for the likelihood of finding life elsewhere in the universe. Lots of ideas. Today, there are several competing theories for how life arose on Earth. Some question whether life began on Earth at all, asserting instead that it came from a distant world or the heart of a fallen comet or asteroid.
Eutrophication is the enrichment of an ecosystem with chemical nutrients, typically compounds containing nitrogen, phosphorus, or both. Eutrophication can be a natural process in lakes, occurring as they age through geological time. Eutrophication was recognized as a pollution problem in European and North American lakes and reservoirs in the mid-20th century. Human activities can accelerate the rate at which nutrients enter ecosystems.
Eutrophication is the process of increase of plant nutrients in water with the consequent. increase in the growth of algae and higher plants. This process is facilitated by external. and internal (such as nitrogen fixation) sources of nutrients. Input of nutrients may be. from point or diffuse sources.