Although Darwin was able to persuade much of the world that a modern eye could be produced gradually from a much simpler structure, he did not even attempt to explain how the simple light sensitive spot that was his starting point actually worked.

The first point one has to get straight in discussions like this, is that ID is not the opposite of evolution. Rather, it is the opposite of Darwinism, which says life evolved by an utterly unguided, undirected mechanism. If god directed the process of evolution, or rigged the universe to produce complex life, then that is not Darwinism - it is intelligent design.

The trap does not work until all the parts were there. The system itself doesn't work until you fit all of them together.

Throughout history there have been many other examples, similar to that of Haeckel, Huxley and the cell, where a key piece of a particular scientific puzzle was beyond the understanding of the age.

Despite some remaining puzzles, there's no reason to doubt that Darwin had this point right, that all creatures on earth are biological relatives

If you take away a rock from a pile of rocks you haven't changed much. It's still a heap of rocks - just a rock or two smaller. Take away a component from the mousetrap and it isn't a mousetrap any more.

A man from a primitive culture who sees an automobile might guess that it was powered by the wind or by an antelope hidden under the car, but when he opens up the hood and sees the engine he immediately realizes that it was designed.