This exercise challenges students to think about the order of and spacing between evolutionary events in geologic time. Teachers may swap out and select their own events that are biologic, tectonic, environmental, etc. I start by having the students work in pairs, and I ask them to place the following alphabetical list of "first occurrences" in geologic time in the correct sequential order: dinosaurs, elephants, fish, humans (modern), insects, mammals, plants, reptiles. Then, students share their determinations in groups of four or five.

This activity was designed for students in central Pennsylvania, but can certainly be adapted. This activity helps students integrate observations of geology and topography, and then to contextualize modern topography in terms of erosion processes and hence rock strength.

Note that many of the days are viable as stand-alone activities, and do not require the full unit.

(Part of the PAESTA In The News - Current Events in Earth and Space Science Series. This series compiles current resources and background materials for recent scientific events in the news. Questions are provided with each topic, written across Bloom's Taxonomic Scale, and can be used for classroom discussion and/or as a writing prompt at the beginning/middle/end of an instructional unit.)

(Part of the PAESTA In The News - Current Events in Earth and Space Science Series. This series compiles current resources and background materials for recent scientific events in the news. Questions are provided with each topic, written across Bloom's Taxonomic Scale, and can be used for classroom discussion and/or as a writing prompt at the beginning/middle/end of an instructional unit.)

(Part of the PAESTA In The News - Current Events in Earth and Space Science Series. This series compiles current resources and background materials for recent scientific events in the news. Questions are provided with each topic, written across Bloom's Taxonomic Scale, and can be used for classroom discussion and/or as a writing prompt at the beginning/middle/end of an instructional unit.)

(Part of the PAESTA In The News - Current Events in Earth and Space Science Series. This series compiles current resources and background materials for recent scientific events in the news. Questions are provided with each topic, written across Bloom's Taxonomic Scale, and can be used for classroom discussion and/or as a writing prompt at the beginning/middle/end of an instructional unit.)

(Part of the PAESTA In The News - Current Events in Earth and Space Science Series. This series compiles current resources and background materials for recent scientific events in the news. Questions are provided with each topic, written across Bloom's Taxonomic Scale, and can be used for classroom discussion and/or as a writing prompt at the beginning/middle/end of an instructional unit.)

(Part of the PAESTA In The News - Current Events in Earth and Space Science Series. This series compiles current resources and background materials for recent scientific events in the news. Questions are provided with each topic, written across Bloom's Taxonomic Scale, and can be used for classroom discussion and/or as a writing prompt at the beginning/middle/end of an instructional unit.)

(Part of the PAESTA In The News - Current Events in Earth and Space Science Series. This series compiles current resources and background materials for recent scientific events in the news. Questions are provided with each topic, written across Bloom's Taxonomic Scale, and can be used for classroom discussion and/or as a writing prompt at the beginning/middle/end of an instructional unit.)

(Part of the PAESTA In The News - Current Events in Earth and Space Science Series. This series compiles current resources and background materials for recent scientific events in the news. Questions are provided with each topic, written across Bloom's Taxonomic Scale, and can be used for classroom discussion and/or as a writing prompt at the beginning/middle/end of an instructional unit.)

In the spring of 2011, the Mississippi River swelled to historic levels.  In 2012, the record-low levels in sections of the Mississippi River have halted cargo traffic.