Metamorphosis, a new Illustra film

Illustra is a film production group that makes high quality films for Christian apologetics such as intelligent design. They've produced several films that adapt the look and feel of science documentaries for the purpose of spreading the Gospel.

Just announced, Illustra's newest effort will focus on Monarch butterflies as iconic species for The Argument Regarding Design (TARD). The Discovery Institute has already begun flogging the video.

Monarch butterflies have long been a creationist favorite, for three reasons. They are beautiful delicate creatures. They migrate absurdly long distances. They have a complete metamorphosis that transforms them from larval caterpillar to adult butterfly.

I'm not going to say anything against the creationists and their sense of wonder at Monarch butterflies. It is a good thing, a trait they share with the rest of humanity. Sadly, I'm sure there is a sect out there that thinks butterflies are the work of Satan, and looking at butterflies might lead to evils like dancing. (An application of the internet meme Rule 34 to the religious tendency to hate.)

How about migration? Currently Monarch butterflies migrate north and south across North America every year, a process that lasts generations! Their winter resting site is a small patch of pine forest in Mexico.

It is a dramatic story, but is it a challenge to evolution? The butterflies are doing something completely natural, following their food sources. Their navigation is based on the chemistry of their brains and antennae, which is determined by their gentics.

At the end of the last Ice Age, Monarch butterflies, or a species that preceded them, must have lived far to the south of Mexico. That inference is simply based on temperature. This species might not have been migratory at all. As the Americas warmed, their range expanded northward through Central America. After a point, though, they can't follow the climate change northward, into the huge new areas of open ecological niches, without migrating back south for the winter.

This could have begun with seasonal migration north and south within a single lifetime. The navigation based on the sun and the circadian clock could develop gradually. (I also don't know the extent of the wintering forest back then, but it could easily have been much larger than it is today.)

The real innovative part of Monarch butterfly migration is its multi-generational aspect. The genes that help navigate the butterfly back south have to be carried by several generations of butterfly for which that specific package of genes does no good whatsoever.

This a great example of what Richard Dawkins called the Extended Phenotype. The bodies of the butterflies (their phenotypes) are just carriers for the selfish genes. What matters is not that the phenotypes make the round trip, but that the genes make the round trip. If a reproducing buttefly suffers a mutation or other variational event on the way north in the springtime, its children might not have the genes to fly back. That variation might expand slightly for the two or three generations of butterflies that live over the summer, but in the fall they die faster than other butterflies (selection on variation) because they are not migrating, not migrating as fast, or in the wrong direction.

So our amazement at Monarch butterfly migration shouldn't lead directly to "Goddidit, therefore Jebus." There are amazing, but completely natural and material, explanations for the behavior. Explanations being elaborated by scientists who don't stop at "Wow", but go on to "How?"

And metamorphosis? Again, for the creationist there is no need to ask how, because Jebus is the Answer.

But for everyone else, metamorphosis is one of the coolest things around!

Lets remember that metamorphosis has been around for a long time. Crustaceans in the ocean do it. It has clear evolutionary value by letting a species exploit two (or more) different niches at different times during the life of an individual.

A very common process during development is the creation of a sheet of cells, and then the destruction of a large group of those cells via a planned cell death (apoptosis). For example, humans have webs between their fingers and toes at a certain point in our embryonic development, and then these webs die back. Cool, but natural - guided by chemical signals guided by genes collected by evolution.

What is happeneing inside the butterfly's coccoon is much the same, though the ratio of surviving and dying cells is very different. Inside the coccoon, most of the cells are dying, giving up their resources and energy to allow other surviving cells reshape the larva into an adult form.

Compared to insects that don't undergo a complete metamorphosis, those that do (like Monarch butterflies) seem to have shifted the timing and extent of hormone releases, a very typical path to speciation known as heterochrony. Heterochrony happens because of variation in gene regulatory networks. Variation with material causes and material effects.

So there is nothing in the history of insects over the last few hundred million years that would suggest that an Intelligent Designer had intervened in the natural processes. It has been said of God that He must love beetles, having made so many of them. But for all that love, he seems to have let all the species of beetle develop the process of metamorphosis just once, in a distant ancestor, and then diversify naturally, almost as if he wasn't involved at all.

It would be great if Illustra's new video intrgated all of this knowledge, and showed how changes from millions of years ago (the origin of insect metamorphosis), climate change (the origin of migration), and ecology united to give us this beautiful, brightly colored animal to share our world with us - and why it was important to preserve the Mexican wintering grounds threatened with deforestation, and provide resting stops along the migration routes stocked with plants that are nutritious to Monarch butterflies. But somehow, I'm afraid the wonder, the sheer wonder is going to dominate.