There is no doubt that life adapts to its planet. But does the planet also adapt to life? Does life alter the planet in a way that it stays habitable?
Life alters our atmosphere, e.g. plants produce oxygen which accumulates in the atmosphere. This benefits other life forms like humans or animals, which gain energy by breathing. This example shows, that life itself helps to create a system which is and stays habitable.
The Earth's crust is split into several plates, which move relative to each other. This process is called plate tectonics. If two plates collide, the heavier one (the oceanic crust) is subducted beneath the lighter one (the continental crust). Hereby, the crust constantly gets recycled into the Earth's interior. The crust itself is altered by life. For example, acid-producing organisms promote the weathering of rocks, and other organisms gain energy by redoxreactions with particular minerals. We try to determine, how the processes in the subduction zone are influenced by that. Particularly important is the transport of water into the Earth's interior. Water reduces the melting temperature of the mantle material, which melts and rises as a consequence. Through the resulting volcanism, new continental crust is produced. Water, which is transported to greater depths, decreases the mantle viscosity, which leads to a more effective heat transport to the surface.
Are there continents on the Earth just because of the origin and evolution of life? Is life responsible for the strong geodynamic activity, or for the perpetuation of plate tectonics? It is well known, that life benefits from this properties: On continents, life has direct access to solar energy, and plate tectonics lead to hot springs in the deep ocean and promote the magnetic field, which in turn protects us from harmful solar radiation. If life is responsible for the growth of continents, we can use this knowledge to search for life on other planets.