Plant population specialist Prof Roger Cousens talks about how the spread of undesirable plants, or "weeds", has dramatically redefined the world’s natural landscapes and coastlines, and what this means for us economically, aesthetically and environmentally. Presented by Dr Andi Horvath.

Physicist Professor Ullrich Steiner explains how nature generates vibrant colors, as seen in many butterflies and beetles, through the structure of materials, and how these properties can be usefully reproduced. Presented by Dr Shane Huntington.

Evolutionary biologist Dr Devi Stuart-Fox explains how bird species in which plumage color form varies from member to member evolve into new species at a faster rate than species of a uniform plumage color form -- confirming a half century-old evolutionary theory. Presented by Dr Shane Huntington.

Australopithecus sediba, discovered in 2008 in southern Africa, is the most significant paleo-archeological find in recent years. These fossilized specimens have anatomical features lying somewhere between those found in Australopithecus africanus and Homo erectus. Geochemist Dr Robyn Pickering discusses the significance of the find, and how the age of A. sediba was determined. With science host Dr Shane Huntington.