We can look high or we can look low in books or in journals, but the result is the same. The scientific literature has no answers to the question of the origin of the immune system.

In Darwin's time all of biology was a black box: not only the cell, or the eye, or digestion, or immunity, but every biological structure and function because, ultimately, no one could explain how biological processes occurred.

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

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.

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

The conclusion of intelligent design flows naturally from the data itself - not from sacred books or sectarian beliefs. Inferring that biochemical systems were designed by an intelligent agent is a humdrum process that requires no new principles of logic or science. It comes simply from the hard work that biochemistry has done over the past forty years, combined with consideration of the way in which we reach conclusions of design every day.

It was a shock to people of the nineteenth century when they discovered, from observations science had made, that many features of the biological world could be ascribed to the elegant principle of natural selection.