If there is an environmental or selective pressure it will contribute to the evolution of an organism by giving an adnantage to the organisms of a population who have a trait which allows them to survive that change. The advantageous genes will be passed on and the number of organisms with the desirable feature will increase over time, however the number of organisms that lack the characteristic will decrease over time. This is evolution by natural selection.
<span>The region of Poland has suffered from the few limits of European states with respect to the international politics of the 20th century. The variations of the borders of Poland is due to the absence of natural barriers in the east-west. The extension of the border is the cause of constant changes in stability that have shaken the country and the inhabitants.</span>
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When chemical substances such as perfume are let loose in a room, their particles mix with the particles of air. The particles of smelly gas are free to move quickly in all directions. They eventually spread through the whole room from an area of high concentration to an area of low concentration.