Humans played a significant role in extinctions over the last 50,000 years. The oldest extinctions of these, during the Pleistocene, may also be at least partly the result of climate change. Some of the strongest evidence for extinction as a result of human activities comes from islands.
How do humans cause extinctions?
Extinctions over the last 1,000 years on islands like New Zealand and Madagascar followed the arrival of the first humans. They show that humans can cause extinctions in three ways: 1. Overexploitation by hunting and fishing. 2. Alteration of habitats by clearing land for agriculture and other uses. Human-produced climate change will be an increasingly important source of habitat destruction in the future. 3. Introduction of animals and plants that have a negative effect on native species. These introduced species may be, for example, new competitors or predators. These processes often happen together, so that, for example, the passenger pigeon became extinct in America in the early 20th century due to a combination of overexploitation and habitat loss.
