These are means by which one species becomes multiple species. The difference is actually pretty simple: In allopatric speciation, a population becomes separated by some kind of geographical barrier that prevents genetic mixing. A simple example would be a pond that was once part of a river. The animals on either side of the barrier would now be subject to selective pressure independently. This is the most common type of speciation. In Sympatric speciation, species diverge without physical separation. One of the best studied examples of this is the rift lakes of Africa.
Manassas 10 Day Weather. 1  Thursday:The Manassas forecast for Apr 20 is 72 degrees and Partly cloudy. There is 60 percentage chance of rain and 3 mph winds from the South-Southwest. 2  Friday:The Manassas forecast for Apr 21 is 75 degrees and Sunny. There is 58 percentage chance of rain and 7 mph winds from the West.
The Bureau of Economic Analysis combines the city of Manassas (along with Manassas Park) with Prince William County for statistical purposes. Manassas also serves as the seat of Prince William County. It surrounds the 38-acre (150,000 m2) county courthouse, but that county property is not part of the city. The City of Manassas has several important historic sites from the period 1850â1870.