To contrast ease of reproduction with the difficulty of becoming an ancestor, Dawkins uses the example of paper folding to explain exponential growth.

Dawkins then tells the audience that exponential growth does not generally happen in the real world – natural factors come into play which control the population numbers, meaning that only an elite group of organisms will actually become distant ancestors.

The long chain of successful ancestors means that the probability of our existence is very small, and we are lucky to be alive.

By turning down the lights and shining a small spotlight on a large ruler in front of him, Dawkins illustrates the darkness of the distant past and of the unknown future.

After expounding on how lucky we are to be alive, and urging us not to waste the precious time that we have, Dawkins brings up the usefulness of science in aiding our understanding of the universe.

He mentions the reply that Michael Faraday gave to Sir Robert Peel when asked about the use of science.

Dawkins explains that Faraday was either referring to the vast potential of a baby, or to the idea that there must be something more to life than growing up, working, getting old, and dying.

He uses a scanning electron microscope to look at small organisms including mites, mosquitoes, and a bee being parasitized by a strepsiptera.

Using a model of a eukaryotic cell, he discusses the mitochondria and presents the audience with a complicated diagram of the metabolic pathways.

By imagining what an advanced alien species would think of humans if they were to arrive on Earth, Dawkins suggests that their science would be similar to ours.

To explain the problem with beliefs in the supernatural, Dawkins conducts a small experiment with the audience to "find the psychic."

Dawkins argues that this is exactly how seemingly supernatural events occur in the real world, especially when the "audience" is the entire population of the planet.

Dawkins then shows the audience a number of designed and designoid objects, including the pitcher plant, megalithic mounds built by the compass termite, and pots made by trapdoor spiders, potter wasps, and mason bees.

Dawkins notes that many animals share similar types of camouflage or protection because of a process called convergent evolution.

Using a volunteer from the audience, Dawkins demonstrates the contraction of the human iris by shining a light into her right eye.

He continues the discussion of artificial selection by explaining the evolution of the ancestral wolf into the many varieties of modern dog.

Quoting from William Paley's Natural Theology, Dawkins discusses the argument from design using the example of the watch and the watchmaker.

Paraphrasing David Hume, Dawkins explains that anything capable of creating humans must itself be highly complicated.

While it is true that designoid objects cannot come about by chance, evolution provides a non-random method of creation – namely, natural selection.

Only after complex designoid objects come to be can you get the final building block of design (microscopes, clay pots, etc.).

The model is then adapted to demonstrate a staged or gradualist solution to finding the right combination to open the lock.

After addressing the claim by Fred Hoyle that probability alone could not produce the complexity of a typed text by Shakespeare, Dawkins introduces the notion of inherited improvements over a number of generations.

Dawkins then illustrates the difference between the reproduction of inanimate phenomena, such as fires spread through sparks, with the inter-generational transmission of DNA in living structures.

The gradual evolutionary adaption of these organisms is demonstrated through the examples of the eye, varieties of wings and protective camouflage.

Dawkins points out that many people throughout history have thought that the natural world existed for our benefit, with examples from Genesis and other literature.

Author Douglas Adams, who is sitting in the audience, is called to read a relevant passage from his novel The Restaurant at the End of the Universe.

He considers the question of flowers seen through the eyes of bees and other pollinators, and performs a series of demonstrations which use ultraviolet light to excite fluorescence in various substances.

This is due to the brain using the internal model to compensate for the relative change in position of images on the retina.

He then goes on the show that the brain uses models to describe the universe by looking at how the brain interprets various optical illusions, such as the hollow-face illusion using a rotating hollow mask of Charlie Chaplin, the "impossible" geometry of a Penrose triangle, the shifting interpretations of the Necker cube and the ability of humans to find faces in random shapes.

He goes on to describe how the complex modelling ability of the brain may have developed due to this imaginative simulation of various possible scenarios or by the development of language, which would allow ideas to be passed from generation to generation, or by technology, which is an extension of human hands and eyes; or, indeed, if it is a combination of all three.