History - Evolve Shape (DVD)

Living organisms have entered into a battle for survival for hundreds of millions of years and the pressure to survive has resulted in ever changing shapes. From the hammerhead shark to the platypus, new and sometimes extreme shapes can mean survival for certain species. But, as nature has proven, sometimes the most basic shapes on earth have the staying power of survival. This episode will explore the evolution of animal shape and how the slightest alteration of a leg or a head can mean the difference between life and extinction.

• documentary