The connective tissues of mammalian brain is called the meninges. There are three layers of this tissue. The outer layer is called the dura mater. The arachnoid is the middle layer and the pia mater is the inner layer of it.
Air pollution is a type of environmental pollution that affects the air and is usually caused by smoke or other harmful gases, mainly oxides of carbon, sulphur and nitrogen. In other words, air pollution is the contamination of air due to the presence or introduction of a substance which has a poisonous effect.
Air pollution can also cause long-term damage to people's nerves, brain, kidneys, liver, and other organs.
In this kind of population, the make up of the population's gene pool will remain virtually the same as long as these conditions hold. In this kind of situation, no evolution can take place, all thing will remain the same. For evolution to occur, competition must exist.