Nick Matzke Tracks the Rise of Anti-Evolution Bills in the United States

The Los Angeles Times is running a story about Nick Matzke's efforts to chronicle the rise of anti-evolution bills in the United States.  The catch: he is using evolutionary principles of descent with modification to show where they came from and how they "adaptively radiated."  Karen Kaplan writes:

The forces opposed to teaching evolution in U.S. public schools just got a new reason to resent the bedrock scientific theory: A researcher has used the principles of evolutionary biology to show that laws ostensibly aimed at improving science education are firmly rooted in efforts to make classrooms safe for creationism.

The analysis of dozens of bills introduced in state legislatures around the country reveals how a single innovation from a small Louisiana parish (population 156,325) was incorporated into 32 subsequent bills through a process the study describes as “descent with modification.” Two of those 32 bills became law and now “negatively affect science education” for students throughout Louisiana (population 4.7 million) and Tennessee (population 6.5 million)

The article is a phylogenetic masterpiece, showing stem and crown groups, based on the wording of different bills in different states.  There is one takeaway that is obvious, based on looking at the graph.  Bills have been forwarded in the following states:

• Alabama
• Florida
• Indiana
• Iowa
• Kentucky
• Louisiana
• Maryland
• Michigan
• Missouri
• Montana
• New Mexico
• Oklahoma
• South Carolina
• South Dakota
• Tennessee
• Texas
• Virginia

In other words, “all over the map.”  Only five of those are southern states, belying the notion that the Bible Belt is the only place you find this kind of legislation. His conclusion:

The creationist antievolution movement has reinvented itself not once but twice in the decade since Kitzmiller. The first guise was “academic freedom,” but after the success of the Louisiana SEA [Science Education Act], AFA [Academic Freedom Act] proposals were almost completely replaced with SEAs. The inclusion of global warming in the SEAs indicates that societal debate over evolution education has the potential to leak into other societal debates where high-quality science education is inconvenient to certain established interests. The passage of SEAs in Louisiana and Tennessee have spread language devised in Ouachita Parish, population ~150,000, to negatively affect science education in two states with ~11.2 million people. Additional policies on the books in other states (table S1) indicate that science educators have substantial work to do to ensure that science classes teach the best science available, rather than false critiques and controversies promoted by creationists. Advocates for science education should not be dissuaded by the strategic vagueness of SEAs: The creationist origins of modern antievolution strategies are clear (table S1), and at least 63 of 65 antievolution bills considered here can be tied directly to creationism through statements in the legislation or by sponsors (SM).

The article is free to non-subscribers (or at least it is at the present moment) and, despite being somewhat technical, is a good snapshot of how these bills have proliferated.

David MacMillan: Understanding creationism, VI: An insider’s guide by a former young-Earth creationist

Panda's Thumb has the sixth installment by David MacMillan on Understanding Creationism.  This one deals with the correspondence between fossil taxonomic studies and genetic evidence as well as the daunting task of constructing phylogenies.  He writes:

The more items you have in a given collection, the more ways they can be arranged. Just five items can be arranged in 120 different ways, and ten items can be arranged in a staggering 3.6 million ways. But the task of placing items into a branching tree is even more complex; for only five items, there are an unbelievable 6.6 × 10198 different possible branching trees. The number of possible trees for just five species is hundreds of orders of magnitude greater than the number of gene sequences that could be used to compare those five different species. So a researcher can’t simply “pick” the sequence that matches; there’s no chance of getting a match in any sequence unless there’s a real phylogeny to work with.

Most importantly, researchers don’t pick only a single sequence. Phylogenetic analysis is performed on many different sequences, and then all of the resulting trees are compared to each other to see which one appears most consistently. Trees produced by random noise will appear only once; accurate trees will appear in multiple sequences. All these clear facts are completely missing from the creationist understanding.

Read the whole thing, especially the response to the “common design” argument.

Phylogenetics: A Horse of a Different Color

New research on horse DNA suggests that the number of horse species in the fossil record has been overestimated. The report, in Science Daily has this to say:

Lead author of the paper, Dr Ludovic Orlando from the University of Lyon, says the group discovered a new species of the distinct, small hippidion horse in South America.

"Previous fossil records suggested this group was part of an ancient lineage from North America but the DNA showed these unusual forms were part of the modern radiation of equid species," Dr Orlando says.

A new species of ass was also detected on the Russian Plains and appears to be related to European fossils dating back more than 1.5 million years. Carbon dates on the bones reveal that this species was alive as recently as 50,000 years ago.

"Overall, the new genetic results suggest that we have under-estimated how much a single species can vary over time and space, and mistakenly assumed more diversity among extinct species of megafauna," Professor Cooper says.

"This has important implications for our understanding of human evolution, where a large number of species are currently recognised from a relatively fragmentary fossil record.

The thorns in the side of phylogenetic analysis have always been intraspecies variation and the overall incompleteness of the fossil record. How do you know that the fossil sample that you have of any given species is representative of the entire range of variation for that species?

This does not have implications for evolutionary trajectories as much as it does for evolutionary taxonomy. Maybe Tiktaalik roseae had considerably more variation in traits than we know based on the sample that we have. But we do know that some of the individuals of the species had traits that link them to later tetrapods as well as some traits that link them to late fish.

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