Parapatric speciation is a form of speciation in which the evolution of reproductive isolating mechanisms occurs when a population enters a new niche or habitat within the range of the parent species. Generally, this occurs when there has been a drastic change to the environment within the original species' habitat. An example of this is the grass Anthoxanthum, which has been known to undergo parapatric speciation in such cases as mine contamination of an area. Selection for resistance/tollerence to certain metals occurs. Flowering time generally changes (in an attempt at character displacement-- strong selection against interbreeding-- as the hybrids are generally ill-suited to the environment) and often plants will become self-pollinating. Speciation refers to the appearance of a new species of life on earth, particularly as seen in the fossil record. ...