Evolutionary process whereby one species evolves into another without any splitting into multiple species Punctuated Equilibrium Model of the rate of evolution in which there are long periods of little change (stasis) in the species punctuated by short bursts of rapid change (usually due to an environmental change) Extinction. Rapid disappearance of a species.
17th Amendment to the U.S. Constitution: Direct Election of U.S. Senators. Americans did not directly vote for senators for the first 125 years of the Federal Government. The Constitution, as it was adopted in 1788, stated that senators would be elected by state legislatures.
The Twelfth Amendment (Amendment XII) to the United States Constitution provides the procedure for electing the President and Vice President. It replaced Article II, Section 1, Clause 3, which provided the original procedure by which the Electoral College functioned.lectoral College under the Twelfth Amendment [edit]. While the Twelfth Amendment did not change the composition of the Electoral College or the duties of the electors, it did change the process whereby a President and a Vice President are elected. The new electoral process was first used for the 1804 election.