The intelligent design theory claims to be scientific but has never demonstrated any ability to quantitatively predict and explain biological phenomena. Here I give you an example how the theory of evolution is crucial in understanding some of the fascinating mysteries in nature. What is the ratio of male and female population in any species? For humans it is close to 1:1. The same approximate 1:1 ratio also holds for a large number of other species. Why? If you really think carefully about it, it doesn't make much sense from an efficient design point of view. A more efficient design should give you far fewer males. A male generally does not contribute to the reproduction process except for his sperms and he can contribute more efficiently by mating with several females. It turns out, that the 1:1 ratio is the result of competition between the males. According to the theory of evolution, if the costs of reproduction for males and females are about the same, then competition across the entire population will lead to the 1:1 ratio. The evolution theory also predicts that if the males compete only in a local population (within a single herd, for example) while the females disperse throughout the global population (leaving the herd at adulthood), then the percentage of males should drop significantly. The ratio is essentially a function of the local population size (Local Mate Competition Model). It turns out, that this prediction is spetacularly confirmed by studies in parasitic wasps. See the article here: http://www.jstor.org/view/00143820/di000260/00p01457/0 In short, the theory predicts that the percentage of sons of a mother wasp should increase with the increasing number of foundresses in a patch, with a specific formula x=(n-1)(2n-1)/n(4n-1) predicted by the evolution theory. The actual data collected from the parasitic wasps are amazingly close to the prediction. This is just one of thousands of examples how evolution theory is confirmed in all parts of biology. The ID people of course are completely ignorant of these studies. Challenge: Can ID people write down an equation on any biological problem?