An externality is the uncompensated impact of a. society's decisions on the well-being of society. b. society's decisions on the poorest person in the society. c. one person's actions on the well-being of a bystander. d. a person's actions on that person's well-being.

the period of human evolution has coincided with environmental change, including ('hominin' refers to any bipedal species closely related to humans – that is, on how do we know earth's climate has changed? a map showing dates and locations of prehistoric archeological sites and migration routes from africa into.