Odds are excellent that extraterrestrial life exists. So why haven’t we found aliens out in the galaxy? Are we looking in the wrong places? New research shows we should look closer to home, even inside our bodies. It turns out that a lot of our DNA is from a mysterious, nonhuman source. Theoretically, alien microbial life can make the journey to Earth from distant worlds, and scientists are finding some unearthly microbes in our upper atmosphere. Could it be from outer space? Could we be part alien? It’s even possible alien life is already here as digital life forms, hiding inside our technology.

Professor Richard Dawkins explain how his unique scientific perspectives have redefined how we think about the world around us and describe his big moment or discovery. Dawkins reveals how he came to write The Selfish Gene in 1976, an explosive book which divided the scientific community and made him the most influential evolutionary biologist of his generation, and how this made him an outspoken spokesman for atheism.

The third episode is devoted to the ways in which plants reproduce. Pollen and a stigma are the two components needed for fertilisation. Most plants carry both these within their flowers and rely on animals to transport the pollen from one to the stigma of another. To do this, they attract their couriers with colour, scent and nectar. It isn't just birds that help pollination: some mammals and reptiles also do so. However, it is mostly insects that are recruited to carry out the task. To ensure that pollen is not wasted by being delivered to the wrong flower, some species of plant have developed exclusive relationships with their visitors, and the gentian and its attendant carpenter bees is one example. Since pollen can be expensive to produce in terms of calories, some plants, such as orchids, ration it by means of pollinia and a strategically placed landing platform. Other orchids offer no reward for pollination, but instead mislead their guests by mimicking their markings and aroma, thus enticing males to 'mate' with them (Pseudocopulation). The most extreme fertilisation method is one of imprisonment, and one plant that uses it is the dead horse arum. It is often found near gull colonies, and mimics the appearance and smell of rotting flesh. Blow-flies are attracted to it, and are forced to stay the night before being allowed to depart in the morning, laden with pollen. Finally, Attenborough introduces the world's largest inflorescence: that of the titan arum.

The ultimate adventure in scientific inquiry, this fascinating program follows the exploits of a small group of pioneering mathematicians who discovered a whole area of study that is revolutionizing all branches of understanding in the world: fractal geometry. Fractals are most recognized as a series of circular shapes with a border surrounded by jagged "tail-like" objects. The program, aimed at the average viewer does a fine job of explaining the background of fractals, first by beginning with the story of Pixar co-founder, Loren Carpenter's work at Boeing, developing 3D terrain from scratch using fractals. From there the program starts at the beginning with an introduction to Benoit Mandelbrot and his revolutionary work. The explanations are full of solid factual information but never talk above the level of a viewer who has some understanding of basic mathematical principles. Once the concept is presented the program spends the rest of the time showing how prevalent the fractal is in life. For a program about a mathematical concept, "Fractals" is very engaging, showing how the process was applied to special effects as far back as the Genesis planet from "Star Trek II" all the way to the spectacular finale on Mustafar in "Star Wars: Episode III." I found myself astonished at how fractals were the source of the lava in constant motion and action during the Obi-Wan/Anakin fight. What is more amazing is when the program delves into practical applications such as cell phone antennas, and eventually the human body. For the average person who enjoys watching science related programs, even on a sporadic basis, "Fractals" will prove to be a very worthwhile experience. The program is well produced, integrating talking head interviews (including some with Mandelbrot himself) with standard "in the field" footage. The structure of the program is very logical and never finds itself jumping around without direction. In simplest terms, this is a program as elegant as the designs it focuses on.

The story of how the secret of life has been examined through the prism of the most complex organism known - the human body. It begins with attempts to save the lives of gladiators in Ancient Rome, unfolds with the macabre work and near-perfect drawings of Leonardo in the Renaissance, through the idea of the 'life force' of electricity, to the microscopic world of the cell. It reveals how a moral crisis unleashed by work on the nuclear bomb helped trigger a great breakthrough in biology - understanding the structure and workings of DNA.

Horizon discovers what your cat really gets up to when it leaves the cat flap. In a groundbreaking experiment, 50 cats from a village in Surrey are tagged with GPS collars and their every movement is recorded, day and night, as they hunt in our backyards and patrol the garden fences and hedgerows. Cats are fitted with specially developed cat-cams which reveal their unique view of our world. You may think you understand your pet, but their secret life is more surprising than we thought.