Importance of the question for archaeological research: Introduction It is difficult to say that humans have not had an impact on their environment. Climate change, for example, has been a hot topic in the developed world since evidence proving the existence of human-caused global warming was made public, leading to an onslaught of theories about its potential effects on our future. But what impact did humans have thousands of years ago when they first colonized North America? The question of what caused the extinction of megafauna during the Late Pleistocene period is one that archaeologists have wrestled with for decades, but why should it matter? Discovering with certainty the cause of the megafauna extinction would simultaneously prove or disprove any of the proposed implications of each existing theory regarding this mass extinction. To better understand these "implications", it is necessary to define and explain the main theories regarding North America. extinction of megafauna. The two most widely supported theories are environmental change and overkill. Two theories that find less support in this field are those of hyperdisease and "keystone herbivores". Proposed Theories and Implications Paul Martin, the most famous and oft-cited proponent of the most popular North American overkill or "blitzkrieg" theory, proposes the following ideas: 1) the disappearance of megafauna followed within 1,000 years of the proposed first introduction of man in North America (Martin PS 969). 2) Kill sites are non-existent for most extinct megafauna because the prey was so ill-equipped to deal with Clovis hunters that they did not have to be tricked or trapped and disappeared into the middle of paper... ...the Keystone theory of megaherbivores uses evidence from extant large African herbivores to suggest that the loss of a (352Owen-Wilson suggests that astute megaherbivores are not particularly prone to disturbance by predators or weather, their populations tend to grow to the point of deficiency nutritional which curiously leads to other vegetation components being trampled or broken by the trampling of megaherbivores (Owen-Smith 355). Sometimes, such damage can actually lead to the creation of diverse landscapes that provide a “greater accessible forage biomass” (Owen). -Smith 355). However, not all soils lend themselves to this type of lucky damage, and megaherbivores can also severely reduce accessible forage biomass. Indeed, whether the megaherbivore will help or hinder depends largely on the water resources in the trampled areas (Owen-Smith 356).