Though humans appeared 125,000 years ago, we were just another mammal species for much of our history, traveling and camping in small groups, hunters as well as potential prey. Then, about 15-20,000 years ago, man began to establish permanent settlements, followed by the development of trade routes, the domestication of animals and the cultivation of plants.
These towns and cities fostered innovation and, over time, the advance of science, industry and technology. As a consequence, our species began to take an increasing toll on natural ecosystems and on the global environment. Habitat destruction, pollution, warfare and the depletion of natural resources began to threaten the fragile balance of life on this planet. Over the past few decades, the environmental movement has begun to counter these effects but the threats imposed by an ever increasing human population remain significant.
How and when will the Age of Man come to an end? Potential scenarios include a natural catastrophe (asteroid strike, super volcanic explosion), the irreversible poisoning of our water and air, nuclear war, a lethal epidemic or the exhaustion of Earth's resources. Should man become extinct (or depart for another planet) before the sun dies, most other life forms will likely have succumbed to the tragic events, leaving bacteria, algae and other primitive species to ignite another sequence of evolution.
