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.
Seventeenth Amendment. The Seventeenth Amendment to the U.S. Constitution reads: The Senate of the United States shall be composed of two Senators from each State, elected by the people thereof for six years; and each Senator shall have one vote.he Seventeenth Amendment, which was ratified in 1913, provided for the direct election of U.S. senators by citizens. Until 1913 state legislatures had elected U.S. senators. Ratification of the amendment followed decades of insistence that the power to elect senators should be placed in the hands of ordinary voters.