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.

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

Thus it seemed to Haeckel that such simple life could easily be produced from inanimate material.

The conclusion of design flows naturally from the data; we should not shrink from it; we should embrace it and build on it.

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.

There is no publication in the scientific literature - in prestigious journals, specialty journals, or books - that describes how molecular evolution of any real, complex biochemical system either did occur or even might have occurred.

I find the idea of common descent (that all organisms share a common ancestor) fairly convincing, and have no particular reason to doubt it.