Szostak begins his lecture with examples of the extreme environments in which life exists on Earth. He postulates that given the large number of earth-like planets orbiting sun-like stars, and the ability of microbial life to exist in a wide range of environments, it is probable that an environment that could support life exists somewhere in our galaxy. However, whether or not life does exist elsewhere, depends on the answer to the question of how difficult it is for life to arise from the chemistry of the early planets. Szostak proceeds to demonstrate that by starting with simple molecules and conditions found on the early earth, it may in fact be possible to generate a primitive, self-replicating protocell. In Part 2, Szostak focuses on work from his lab studying the membrane components of a simple protocell and in Part 3 of his lecture, he describes experiments to investigate nucleic acid replication by chemical rather than enzymatic mechanisms. Published by iBiology under a CC BY-NC-ND 3.0 license. Usage policy Link to original