Emergence of Life


How did life emerge on Earth? How have life and Earth co-evolved through geological time? Is life elsewhere in the universe? Take a look through the 4-billion-year history of life on Earth through the lens of the modern Tree of Life!

This course will evaluate the entire history of life on Earth within the context of our cutting-edge understanding of the Tree of Life. This includes the pioneering work of Professor Carl Woese on the University of Illinois Urbana-Champaign campus which revolutionized our understanding with a new “Tree of Life.” Other themes include:
-Reconnaissance of ancient primordial life before the first cell evolved
-The entire ~4-billion-year development of single- and multi-celled life through the lens of the Tree of Life
-The influence of Earth system processes (meteor impacts, volcanoes, ice sheets) on shaping and structuring the Tree of Life
This synthesis emphasizes the universality of the emergence of life as a prelude for the search for extraterrestrial life.

What you will learn


In this module, you will become familiar with the course, your instructor, your classmates, and our learning environment.

Week 1 – Geological Time and the Nature of Science

The week begins with a discussion of the historical and philosophical approaches that have been developed for the completion of scientific research, with the work of Professor Carl Woese evaluated as an example. The basic tools required for this type of scientific reasoning and the ability to overcome the challenging concepts of scale and complexity are then presented. Finally, we’ll explore the dynamic formation of the Earth itself with respect to the environmental conditions present on the earliest and most ancient version of planet Earth.

Week 2 – The Tree of Life and Early Earth Environments

The advent of life on Earth came about as a result of a remarkable confluence of physical, chemical, and biological processes, all of which were intrinsically linked to rapidly changing early Earth environments. Within this context, cutting-edge approaches in molecular phylogeny by Professor Carl Woese revealed new understandings of the emergence of life and the possible distribution of life within the cosmos. All this and more will be explored in this week’s lessons!

Week 3 – Fossilization and Precambrian Life-Earth Interaction

This week, you’ll explore how scientists interpret ancient fossilized life, which yields remarkably detailed and complete reconstructions of the lifestyles of ancient organisms that have been deceased for hundreds, thousands, millions, and even billions of years. These reconstructions provide valuable information regarding the evolutionary success of organism morphology and lifestyle.

Week 4 – Paleozoic Life After the Advent of Skeletons

This week, you’ll learn more about the Cambrian Explosion, which led to the development of external hard skeleton components at 542 million years before present. The initial successes of the invertebrates were shortly followed by the appearance of vertebrates with internal skeletons. Life then utilized these newfound evolutionary capabilities, beginning distinct cycles of radiation, diversification, and extinction, which define the three great Eukarya faunas of the Phanerozoic.

What’s included