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

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.

The theory of undirected evolution is already dead, but the work of science continues.

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.

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

In order to say that some function is understood, every relevant step in the process must be elucidated.

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.