7.+Human+decisions+and+activities+have+had+a+profound+impact+on+the+physical+and+living+environment.

MAJOR UNDERSTANDINGS 7.1a Humans depend on their natural and constructed environments. 7.1b Over time humans have changed their environment by cultivating crops and raising animals, creating shelter, using energy, manufacturing goods, developing means of transportation, changing populations, and carrying out other activities. 7.1c Humans, as individuals or communities, change environments in ways that can be either helpful or harmful for themselves and other organisms. 