While doing a bit of tidying in my office (a mammoth task!) I came across a printout of Jonathan Wells’ infamous list, "10 questions to ask your biology teacher". Wells is a senior fellow with the US-based Discovery Institute, which actively promotes intelligent design as an alternative to evolution. His list of questions is (I suppose) intended to sow doubt in students’ minds, but what it does very clearly is show his woeful lack of understanding of some fairly basic ideas.
Anyway, I thought I might work my way through them, starting… now.
Question #1 is a good example of misinformation by omission.
ORIGIN OF LIFE. Why do textbooks claim that the 1953 Miller-Urey experiment shows how life’s building blocks may have formed on the early Earth — when conditions on the early Earth were probably nothing like those used in the experiment, and the origin of life remains a mystery?
The Miller-Urey experiment was ground-breaking at the time. It was the first serious attempt to replicate the conditions under which the chemical precursors of life on Earth might have developed. And it was based on scientists’ understanding of those conditions at the time ie in 1953. The experiment simulated the effect of lightning in the planet’s early atmosphere, by passing electrical discharges through a mixture of gases that included hydrogen, water vapour, ammonia & methane. This sort of atmosphere would have been strongly reducing. A flask of warm water in the reaction system represented an early ocean. Miller & Urey sampled the ‘ocean’, & found that a range of organic molecules had formed, including amino acids & complex hydrocarbons. They concluded that they had demonstrated a possible mechanism for the formation of the organic compounds that are the building blocks of life.
But – read a textbook like Campbell & Reece’s Biology, & you won’t see the claim that this is how life might have formed. What you will see is recognition of the significance of Miller & Urey’s work, and then the comment that we now think that the early atmosphere was nowhere near as strongly reducing as first thought. Instead, it was probably made up mostly of nitrogen & carbon dioxide. And we no longer think that those first organic compounds formed in the atmosphere. A more likely site is in the oceans around undersea volcanoes and what today we’d call ‘black smokers’ – vents where superheated water & dissolved minerals pour into the sea.
In other words, Wells is holding up work done over 50 years ago as an ‘example’ of the current state of scientific thought, and omitting to say that we’ve moved on since then. What’s more, evolutionary theory deals with the evolution of life, rather than its origins, so question #1 is also something of a red herring.