Humans are subject to the same limiting factors as other species including

Grazing animals and the grasses they eat have both evolved in response to each other’s influence. This process is known as

Political and economic factors have a great deal of influence on

Repeatability in an experiment is important because

An important determiner of the nature of aquatic ecosystems is

Which of the following fossil fuels causes the least environmental problems?

Agricultural runoff consists of a mixture of compounds that serve as nutrients. The two primary nutrients are ________ and __________.

Charles Darwin is generally credited with developing the concept of

An important by-product of the process of photosynthesis is

Which of the following pairs of events appear to be linked?