Tömegkihalás

Tömegkihalás, or mass extinction, refers to the sudden disappearance of a large number of species from the Earth's biosphere. These events are typically characterized by a significant and rapid loss of biodiversity, often occurring over a relatively short geological time scale. The most well-known mass extinction event is the Permian-Triassic extinction, which occurred approximately 252 million years ago and resulted in the loss of about 96% of marine species and 70% of terrestrial vertebrate species.

Mass extinctions can be caused by a variety of factors, including asteroid impacts, volcanic activity, climate change, and changes in ocean chemistry. The asteroid impact that likely caused the extinction of the non-avian dinosaurs at the end of the Cretaceous period is one of the most famous examples of an extraterrestrial cause for a mass extinction event.

The study of mass extinctions is important for understanding the resilience of ecosystems and the factors that drive biodiversity. Scientists use fossil records, geological data, and computer models to investigate the causes and consequences of these events. The ongoing loss of biodiversity due to human activities, such as habitat destruction and climate change, is often referred to as the current "sixth mass extinction." Understanding past mass extinctions can provide valuable insights into the potential impacts of these ongoing threats to biodiversity.