Skip to 0 minutes and 3 secondsIn this week, we spoke about the end Triassic extinction event and how this spurred on the evolution of dinosaurs and mammals. We had a chance to hear Emil Krupandan talk about the early radiation of dinosaurs and then, towards the end of the week, we spoke about the end Cretaceous extinction event and the subsequent radiation of mammals. We then heard from Pippa Haarhoff about the five to seven million year old fossils at the West Coast Fossil Park. We also spoke to Emeritus Professor William Bond about the spread of the grasslands, and we chatted to archaeologist Professor Becky Ackermann about how and when humans became the dominant animals on our planet. The end Triassic extinction event is highly significant.

Skip to 0 minutes and 51 secondsLike today, global warming caused by increased carbon dioxide, may have been the cause. The difference, of course, is that the increase in carbon dioxide then was the result of volcanic activity. Today, of course, it is industrialization that is mainly to blame. Irrespectively, we see global warming causes major shifts in ecosystems, and from this point onwards, right until the end of the Cretaceous we see dinosaurs dominate terrestrial environments. Next week, we're going to talk about the current biodiversity crisis. We will be talking to scientists from a range of different disciplines about how we can avert the sixth extinction.

Extinctions and Diversifications

We saw this week the End of the Triassic event that may have resulted in increased atmospheric CO2 and global warming i.e. the same factors that scientists today are drawing public attention to – but this time caused by us, the dominant species. In this week we have also seen how global domination by the incredibly successful dinosaurs came to an end at the End Cretaceous extinction event. Scientists think that this extinction event was caused by a combination of causes: volcanic eruptions, sea level changes and an asteroid impact.

Next week we will be talking about the contemporary times - often called the Anthropocene - and whether we are facing a sixth mass extinction.

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This video is from the free online course:

Extinctions: Past and Present

University of Cape Town