The promise of jobs and prosperity, among other factors, pulls people to cities. Half of the global population already lives in cities, and by 2050 two-thirds of the world's people are expected to live in urban areas. But in cities two of the most pressing problems facing the world today also come together: poverty and environmental degradation.
A mutation is one form of genetic variation.
One way to reduce water consumption on farms is to use drip irrigation. Drip irrigation is a way of watering the plants in the farm directly to their roots. By this less water are consumed and you are sure that the plant really received the amount of water that they need.