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

In the 19th century the anatomy of the eye was known in great detail and the sophisticated mechanisms it employs to deliver an accurate picture of the outside world astounded everyone who was familiar with them.

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

Since natural selection requires a function to select, an irreducibly complex biological system, if there is such a thing, would have to arise as an integrated unit for natural selection to have anything to act on.

In private many scientists admit that science has no explanation for the beginning of life... Darwin never imagined the exquisitely profound complexity that exists even at the most basic levels of life.

In the abstract, it might be tempting to imagine that irreducible complexity simply requires multiple simultaneous mutations - that evolution might be far chancier than we thought, but still possible. Such an appeal to brute luck can never be refuted... Luck is metaphysical speculation; scientific explanations invoke causes.

The basic structure of proteins is quite simple: they are formed by hooking together in a chain discrete subunits called amino acids.