“Gene flow, also called , is any movement of from one to another. Gene flow includes lots of different kinds of events, such as being blown to a new destination or people moving to new cities or countries. If are carried to a population where those genes previously did not , can be a very important source of genetic . In the graphic on the website, the gene for coloration moves from one population to another.”

the second type of galaxy is called a barred spiral, which has a thing called a bar straddling the nucleus

the cost of mining is extremely low compared to the money earned from mining, creating income to improve the environment.

imagine a line passing through the center of earth that goes through both the north pole and the south pole. this imaginary line is called an axis. earth spins around its axis, just as a top spins around its spindle. this spinning movement is called earth's rotation. at the same time that the earth spins on its axis, it also orbits, or revolves around the sun. this movement is called revolution.