Facts and theories are different things, not rungs in a hierarchy of increasing certainty. Facts are the world's data. Theories are structures of ideas that explain and interpret facts. Facts do not go away while scientists debate rival theories for explaining them. Einstein's theory of gravitation replaced Newton's, but apples did not suspend themselves in mid-air pending the outcome.

People are storytelling creatures. We like stories that go somewhere, and therefore we like trends - because trends are things that either get better or get worse, so we can either rejoice or lament. But we mistakenly depict many things as trends moving in some direction. We take the "full house" of variation in a system and try to represent it as a single number, when in fact what we should be doing is studying the variation as it expands and contracts. If you look at the history of the variation in all its complexity, then you see there's no trend.

I can envision observations and experiments that would disprove any evolutionary theory I know.

Life is a copiously branching bush, continually pruned by the grim reaper of extinction, not a ladder of predictable progress.

If we are still here to witness the destruction of our planet some five billion years or more hence, then we will have achieved something so unprecedented in the history of life that we should be willing to sing our swansong with joy - Sic Transit Gloria Mundi.

All organisms vary, and it's just folk knowledge. You just have to look around a room of people, and everybody knows that it's true. Darwin didn't know the mechanism of heredity, but you don't have to. You just need to know the fact of it.

If any issue should unite liberals and conservatives, anyone who cares about the integrity of human achievement or respect for human accomplishment, may we not all pledge to avoid the silly censoring that can lead to a codification of Orwell's Newspeak? Consider John Milton's reasons for why good arguments are often lost: 'For want of words, no doubt, or lack of breath!'