Life on Earth: Diversification and Extinctions

Overview

Discover the diversity of life on earth and how this biodiversity has been shaped by five mass extinction events that occurred in the distant past. Each week we interview scientists about how their research informs us about the biodiversity of our planet including the earliest life forms; fish and tetrapod diversification; the radiation of reptiles and the later domination of dinosaurs; and the rise of mammals. We focus on the five previous mass extinction events to explain this incredible story of life on earth. The fossil record reveals evidence of species that went extinct during each of these catastrophic events and the recovery thereafter when surviving biota diversified. Turning to the present and the Anthropocene period, we look at how human behaviour is negatively impacting Earth’s ecosystems. We conclude by considering the threat of the so-called ‘sixth extinction’, and we discuss ways in which we can mitigate the effects of climate change and the ‘sixth extinction”.

Syllabus

Module 1: Beginnings of Life on Earth

We’ll be exploring the history of life on Earth and the origins of biodiversity by interviewing researchers who share insights about extinction event. In the first two billion years of Earth’s history, bacteria and bacteria alone ruled the world. Bacterial colonies are evident in the fossil record as stromatolites, which are finely layered dome structures produced by bacteria capable of photosynthesis.

Module 2: Life in the Marine Realm and Early Ecosystems on Land

Exploring fish and tetrapods diversification after the first and second extinction events.

Module 3: The Biggest Mass Extinction Event

The catastrophic End Permian extinction event was the biggest extinction event of all time. This almost wiped out life on earth. We will look at before and after this End Permian Extinction event.

Module 4: Most Recent Extinction Events

The 4th and 5th extinctions are very significant in influencing the development of life. We look initially at how dinosaurs come to dominate the earth for several million years.

Module 5: A Possible Sixth Extinction?

In this final module, we explore what we know of the present day loss of biodiversity. We take a close look at some of the negative human impacts on environments and examine our ability to stop the rampant destruction.