For example, effects of climate change as a contributing factor towards ecological collapse are demonstrated in the Ordovician–Silurian extinction events.[5] A possible cause of the Ordovician Extinction was global cooling which affected the habitats of marine life. Consequently, sea creatures such as trilobites, brachiopods, and graptolites became extinct.[6] Furthermore, Karabonov and colleagues conducted a study to show how during the Last Glacial Maximum (LGM), alternations in the environment and climate led to ecological collapse in Lake Baikal and Lake Hovsgol which then led to species evolution in these systems.[7] The collapse of Hovsgol's ecosystem during the LGM brought forth a new ecosystem, with limited biodiversity in species and low levels of endemism, in Hovsgol during the Holocene.