I sometimes forget that not everyone gets into fights on the internet about stuff. While I’ve been observing the debate over climate change and evolution and the existence of God and alt-med pseudoscience and any other number of skeptical hot topics for a while now, I often make the faulty assumption that other people are a) as interested and b) as skeptical as I am about these things. As a result, I tend to regard people who believe in astrology, or ghosts, or biblical creation,  as being curious oddities when they are in fact, more often than not simply people who aren’t particularly experienced in skeptical inquiry.

It is for this reason that this blog has, from time to time, become a dumping ground for my handful of skeptical tools, thought experiments, critical arguments, and whatever other devices I use on a day-to-day basis when I’m trying to navigate the morass of contradictory claims that are at the heart of most of these “controversies”. Today will be another one of those.

Whenever I am confronted with a new idea or a theoretical framework, I like to ask myself the question “What would the world look like if this were true?” It’s a useful thought experiment in which you are invited to re-start the world from scratch and, while keeping all the other variables the same, imagine what the outcome would be if a certain rule were true. It’s the inverse of the usual scientific process wherein we look at the evidence in aggregate and then try to figure out what the rules are; in this thought experiment we assume the rule to be true and then imagine what the world would look like as a result.

Rule #1a: Creationism – the Earth was created by a supernatural force in (more or less) its present form about 10,000 years ago. Current geological and geographical features that appear to be due to the effect of much more than 10,000 years of time are in fact caused by a massive flood.

What would the world look like if Creationism was true?

It is entirely possible that different species were created using the same set of rules, so the existence of a single mechanism underpinning living organisms (DNA/RNA transcription) is neither ruled out or necessitated by this rule. Types of animals (called “kinds” in Creationist jargon) would not show anything but trivial similarities in terms of their underlying physiology, microbiology, genetics, since they have all been created separately and are not designed to interbreed. There would be no need for wasted or vestigial organs, since these organs would only waste energy. A consistent fossil record would exist that shows only superficial changes over time, consistent with the observed rate of change in physiology in the current time (within reasonable error bars). Species would show evidence of physical migration from a single point of of origin (in the Middle East), spreading out to their current locations, and the same types of animals would occupy ecological niches everywhere (birds are the only ones that fly, fish are the ones that swim, etc.) since there is no reason to change a working pattern. Species would not acquire new characteristics over time, since they were created perfect the first time. Floods would exhibit similar effects (albeit to a smaller degree) on geology that can be observed and extrapolated.

Rule #1b: Evolution – all existing life has a common origin, having reached its present form via a process of change due to a combination of genetic mutation and changes in environment that favors certain trait changes over others.

What would the world look like if evolution were true?

Different species would have many genetic commonalities – no species would use a completely unique process of gene replication, and similarity between different types of species would be on a gradient rather than randomly distributed. Similarities would also be seen in embryology, comparative physiology, and microbiology since they all came from a single source rather than being created different. There may (or may not) be gene sequences and organ systems that are completely useless or have trivial utility in one species, but have working analogues in other species – these would be caused when two different species diverge from a common ancestor due to environmental differences. Fossil records would show animals that are similar to a number of different species but are no longer in existence, as well as some that are still in existence (since environmental changes happen with different frequency and magnitude). Species would exist only in certain areas, while there would be no evidence of them in others, as their ancestors might have had common habitat but have left that area, went somewhere else, and adapted to the change in environment. By the same token, ecological niches would be filled by many different kinds of animals – there would be mammals that fly and birds that swim, plants that eat flies and insects that fertilize soil. Species would, if given sufficient time and divergent enough environments, gradually change and become different enough as to be considered two different species.

The last step of this process is to look at the world that exists and decide which rule best resembles our observed reality. If the rule is in conflict, there are two possible explanations: 1) the rule is false, or 2) there are other forces at work underlying reality that are not fully caught by observation, and further observation will expose them. Of course creationists are loath to accept #1, and will rush to find exceptions and “explanations” for why the rule is still valid (Ken Ham’s floating log bridges, for example). This, however, is simply back-filling – throwing up hastily-assembled assertions to prop up a preconceived conclusion rather than following the existing evidence.

I was going to do a few more examples, but I’m on vacation and I’m coming dangerously close to my 1000 word limit, so I’ll do another one of these another time.

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