Answer: It reduces the usefulness, productivity, and biodiversity of the land and is one cause of desertification and erosion. Overgrazing is also seen as a cause of the spread of invasive species of non-native plants and of weeds.
Answer:
The pressure of a gas increases in a closed container if the volume of the gas decreases. Pressure and volume have inverse relationship which means if one increases the other decreases and vice versa. If pressure increases, volume of a gas decreases because there are a lot of empty spaces present between gas particles which are filled when gas particles come closer to each other due to pressure applied.
The answer is speciation by geographic isolation. When the population of a species gets separated due to reasons such as continental drift, mountains, canyons, etc. then each separated group of population may survive and adapt to their respective environment leading to speciation. These barriers do not allow the evolving populations to interbreed initially and over time when they evolve into different species they become completely reproductively isolated.