Australasian Science Magazine

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By Nick Matzke

It’s 10 years since US legislation drafted to stop the teaching of “intelligent design” was ruled unconstitutional, yet anti-evolution legislation continues to replicate and “evolve” across the USA.

Many who have studied the anti-evolution movement have noted that “creationism evolves”. Usually scholars make the joke, note the irony and move on with traditional approaches to history.

But “creationism evolves” can be made into a more literal, scientific statement. I have estimated the evolutionary family tree, or phylogeny, of 67 anti-evolution policies proposed in the United States between 2004 and 2015 (www.tinyurl.com/zxkyr38).

I describe all of these policies as “stealth creationism”. They never mention creationism or “creation science”, and they rarely mention “intelligent design”, primarily because these topics were ruled to be in violation of the US Constitution's prohibition on government promotion of religion in public schools. (The last major court case, Kitzmiller v. Dover, was about “intelligent design” and was decided on 20 December 2005). The stealth creationism policies attempt to portray evolution as “controversial”, encourage teachers to “critically analyse” evolution (by promoting bogus creationist arguments against evolution), and the policies attempt to prevent school administrators from correcting teachers who are promoting pseudoscience.

Because the creationists are adopting stealth strategies and trying to hide the sectarian basis of their activities, I hypothesised that a phylogeny could be used to trace what the creationists were up to. This phylogeny tells us not only the family relationships between policies but also gives information about which sources particular creationists copied their policies from, and gives insights into which policies are chosen for future legislative attempts.

While a phylogeny is usually an evolutionary tree that shows the family relationships between DNA sequences or species, it can be used for far more than DNA. Phylogenetic trees have been constructed for proteins, chromosomes, fossils and even cultural objects like languages, musical instruments and texts.

One famous example was a phylogeny of Little Red Riding Hood, which examined variants of the bedtime story across Europe, Asia and Africa. In some versions of the story, the wolf is replaced with a tiger, or the red riding hood is some other garment. Versions of the story that share these variants are more likely to have shared history, just like the fact that our DNA is most similar to chimpanzee DNA indicates that chimps are our closest living relatives. By examining hundreds of such variants using computer programs, a phylogenetic tree with the best fit to the data can be estimated.

A new term for the application of phylogenetics to cultural objects is phylomemetics – the phylogenies of memes. The term “meme”, of course, was invented by Richard Dawkins in his 1976 book The Selfish Gene. Dawkins drew an analogy between ideas that spread in our culture, and genes that spread in populations.

While memes have become firmly embedded in popular culture, the scientific study of them has lagged behind. Early discussions devolved into debates about how they should be defined, and whether or not thinking of ideas as objects replicating in the culture under natural selection was any more useful than traditional historical analysis how and why certain ideas become popular in the culture.

Phylomemetics provides a way forward. While evolutionary biologists remain interested in reconstructing phylogenies for their own sake – we all want to know what Darwin's Tree of Life will look like when all of the data is in – much of the scientific focus is now using phylogenies to test hypotheses about how evolution works. Phylogenies allow us to measure things like the rates of speciation, extinction and evolutionary change, and the correlation of these rates with other factors. Do ice ages promote speciation or extinction? Do all species have the same chance of producing new species, or do only a few species have key traits that cause them to take over, driving others to extinction?

If we can use phylomemetics to do the same thing for memes, then we will be on our way to having an actual science of memes. To that end, I thought that creationist legislation would be a perfect test case.

One key requirement for phylomemetics is that memes are large and relatively stable. You need to have dozens or hundreds of identifiable characteristics to build a good phylogeny. This is the reason that a phylogeny of LOLcat memes on the internet would probably be difficult. There are only so many characteristics you can get out of the viral meme “I CAN HAZ CHEESEBURGERS”.

But with legislative proposals we have the complete text, along with the date that the proposal was published. And, unlike fossil species, we think we have all of the bills proposed between 2004–15 in a database of anti-science legislation maintained by the National Center for Science Education (NCSE), which is devoted to defending science education from political and religious attacks.

To do the phylomemetic analysis, I took 67 policies from the NCSE database and spent several weeks lining up the texts, coding the variants (418 kinds of variation for each of 67 policies) and then running statistical analyses on the computer. The main program I used was BEAST (Bayesian Evolutionary Analysis Sampling Trees), which is the workhorse program behind thousands of published papers. BEAST specialises in analyses that infer the timing of events in an evolutionary tree. If you have ever heard of a evolutionary study that makes conclusions about how many million years ago an event occurred, it was probably a study that used BEAST.

Biologists use BEAST to study everything under the sun, from languages to dinosaurs, but BEAST is also used to study the evolution of diseases like HIV and Ebola. In fact, in 2014, while the Ebola outbreak was still going on in West Africa, a paper published in Science used dated samples of the Ebola virus to track its spread and estimate when Ebola was introduced into each new country. These estimates were measured with a precision of weeks rather than millions of years. A shocking feature of that paper was the postscript, which noted that five of the coauthors of the study – health workers in West Africa that had helped collect the virus samples – had died of Ebola before the paper was published.

This goes to show that phylogenetics can be life-and-death stuff, and this is part of the reason I get annoyed with creationist attempts to get politicians to pass laws suggesting that evolution is controversial science that might just be make-believe.

A great feature of BEAST is its speed. In just a day or two I could sample tens of millions of possible dated phylogenetic histories of anti-evolution bills. It turns out that these bills show a strong signal of successive copying – Darwin's “descent with modification” – so the summary tree is likely a close estimate of the true history (which we never know for sure).

What did this tree show? The strong signal indicates that a creationist legislator tended to write a bill by copying from one previous bill, rather than combining text from multiple bills or re-writing bills from scratch.

While this is the strong overall pattern, there was one important exception. In 2008, legislators in Louisiana combined text from previous bills known misleadingly as “Academic Freedom Acts” – a phrase promoted by the Discovery Institute, which was the main organisation behind “intelligent design” creationism – with text from a policy passed in Ouachita Parish in Louisiana (a parish is equivalent to a county). This new bill was called the Louisiana Science Education Act, and it was passed state-wide in Louisiana.

Another thing that the phylogeny indicates is that “success sells”. After the passage of the Louisiana bill, the “Science Education Act” language became the most popular source of new legislative proposals. While most bills fail – sometimes only after emergency last-minute opposition from scientists and science educators – a similar Science Education Act passed in Tennessee in 2012, and this became the source for new bills. By 2015 the Science Education Acts had completely taken over from the Academic Freedom Acts.

One factor in the relative success of the Science Education Acts appears to be the list of sciences that are considered “controversial”. The Science Education Acts target not only evolution and origin-of-life studies but also human cloning and global warming. In the US, a strong alliance has developed between religious conservatives and economic conservatives, and in the past 10 years the anti-science attitudes that fundamentalists have long nurtured in their opposition to evolution seem to have been transferred to the topic of climate change.

The inclusion of human cloning in the list is peculiar. Human cloning has not occurred, and pretty much everyone agrees that it should not, so there is not even a moral controversy, let alone a scientific one, but it may be included just to distract critics who focus on the long history of creationist attempts to interfere with the teaching of evolution.

So it appears that politicians motivated by fundamentalist religion are now attempting to subvert science education about not only our past but our future. Phylogenetic analysis of these efforts strongly indicates that if a policy is passed in one jurisdiction it is likely to succeed elsewhere. Indeed, the Discovery Institute is now promoting a new model bill for the 2016 legislative session that is copying the Louisiana strategy and targeting the teaching of “controversial” topics such as evolution, the origin of life, human cloning and climate change.

Scientists, science educators and science fans need to “stay on their toes”. Much like pathogens that are evolving drug resistance, previous wins for science education are not likely to drive antiscience to extinction. Instead, new antiscience efforts are evolving.

Nick Matzke is a Discovery Early Career Research Award fellow in the Division of Ecology, Evolution and Genetics at the Australian National University. From 2004–05 he was a researcher for the victorious plaintiffs in the federal Kitzmiller v. Dover trial in Pennsylvania, where the court ruled that teaching “intelligent design” in a government high school was an unconstitutional establishment of religion.