Students in grade 8 understand how atomic structure determines chemical properties and how atoms and molecules interact. Students explain how the water cycle and air movement are caused by differential heating of air, land, and water and how these affect weather and climate. Students understand that natural and human events change the environmental conditions on the earth. Students 44 Indiana Department of Education Elementary and Middle Level Subject Descriptions understand the predictability of characteristics being passed from parent to offspring. Students will understand how a particular environment selects for traits that increase survival and reproduction by individuals bearing those traits. Students evaluate the evidence of evolution and relationships/categorization among organisms. The science and engineering processes as well as engineering opportunities are integrated with content throughout the course. Along with the current academic standards for this subject, the Science/Technical Studies Content Area Literacy Standards are incorporated with the expectation of a continuum of reading and writing skills development.