Living indicators are species that are sensitive to changes in the environment. For example air pollution can be monitored by looking at lichen, which are sensitive to sulphur dioxide in the air. The number of lichen at a particular location indicates how clear the air is. Similarly, mayfly larvae are good indicators for water pollution because they're sensitive to the concentration of dissolved oxygen in water.
Non-living indicators are things like satellites which can measure the temperature of the sea surface, weather stations that measure atmospheric temperature, rain gauges to measure rainfall, and dissolved oxygen meters to measure concentration of dissolved oxygen in water.
The process of physical change in state, that occurs when water vapor or gas converts into a liquid is condensation. According to the kinetic molecular theory, the particles lose kinetic energy and slow down and thus become more arranged and have a definite shape but an indefinite volume, a liquid.
Answer:
A genetic drift is defines as the change in the allele frequency of an existing population. It arises as a result of random variation in a population. The rate of genetic drift would be greatest in a small population that are geographically isolated from the parent population. A change in the allele frequency of a population as a result of chance rather than the natural selection.
