As can be seen even by this limited number of examples proteins carry out amazingly diverse functions.

The question is: exactly how did life get here? Was it by natural selection and random mutation or was it by something else? Everybody - even Richard Dawkins - sees design in biology. You see this design when you see co-ordinated parts coming together to perform a function - like in a hand. And so it's the appearance of design that everybody's trying to explain. So that if Darwin's theory doesn't explain it we're left with no other explanation than maybe it really was designed. That's essentially the design argument.

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.

It is a shock to us in the twentieth century to discover, from observations science has made, that the fundamental mechanisms of life cannot be ascribed to natural selection, and therefore were designed. But we must deal with our shock as best we can and go on.

Skin is made in large measure of a protein called collagen.

For example, both humans and chimps have a broken copy of a gene that in other mammals helps make vitamin C. ... It's hard to imagine how there could be stronger evidence for common ancestry of chimps and humans. ... Despite some remaining puzzles, there's no reason to doubt that Darwin had this point right, that all creatures on earth are biological relatives.

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.