Bombardier Beetle Mechanism Explained

A beetle that has become a creationist icon is examined by evolutionists in a leading journal.

Dr. Duane Gish used the bombardier beetle decades ago to challenge evolution: how could a mechanism that delivers a carefully timed and aimed explosion evolve by stepwise Darwinian processes? In Science, evolutionists from MIT, U of Arizona and Brookhaven National Lab learned more about this amazing beetle’s firepower—but they had very little to say about how it might have evolved. Emily Demarco, summarizing the paper in the same issue of Science, had zilch to say about Darwin but quite a bit about design. Look first at her parts list, then how they work together:

When threatened, the beetle contracts muscles that open a structure called the interchamber valve, allowing a droplet of a mixture of hydrogen peroxide and chemicals known as hydroquinones to flow from one chamber in the gland to another, the team reports online today in Science. There, the droplet comes into contact with the peroxidase and catalysts that create the noxious chemicals and the reactions that explode them out of the insect’s rear. Pressure from the explosion distends a flexible structure called the expansion membrane, closing the interchamber valve and disrupting the flow of chemicals. When pressure in the chamber drops after the explosion, however, the valve opens again, and a new droplet begins the process once more. Such new insight could help improve technologies like fuel injectors in internal combustion engines, the researchers say.

The Editor’s Summary is also silent about evolution:

Bombardier beetles shoot a toxic pulse at potential predators and other harassers. The toxic spray is created by a chemical reaction that occurs inside the beetle’s body. Although the details of the reaction are known, how the beetle is able to precisely combine the chemicals at appropriate times and release the pulse at regular intervals has remained a mystery. Arndt et al. used synchrotron x-ray imagery to observe the process as it occurs within live beetles. Expansion and contraction of an internal expansion membrane facilitate the precise cyclic injection of reactants and the subsequent ejection of toxic sprays that keep the beetle’s predators at bay.

The only mention of evolution is at the end of the paper, and it only concerns one aspect of the bombardier beetle’s mechanism:

The pulsed spray mechanism of brachinine bombardier beetles is remarkably elegant and effective, protecting these beetles from nearly all predators (and incautious humans). The passive mediation of pulsation by mechanical feedback from the explosion is advantageous because it provides automatic regulation of reactant use. Further, the evolutionary change from a continuous defensive spray (exhibited by close relatives of the brachinines) to a pulsed spray required only relatively minor changes to the reaction chamber inlet structures rather than the evolution of novel valve-closing muscles.

In other words, they are only talking about how a continuous spray might have evolved into a pulsed spray. This still leaves unaddressed how the reactants could combine without destroying the beetle instead of its target.

An MIT press release shows the X-ray videos taken of the firing mechanism, shot at 2,000 frames per second. In the embedded video clip (2 minutes), lead author Eric Arndt, an MIT grad student, begins by saying he wants to understand the beetle and what we can learn from it, but then at the end gives his evolutionary slant about how a continuous spray evolved into a pulsed mechanism by a very “simple” modification.

Five years ago, creation researcher Andrew McIntosh of Leeds University won an award for design of a pressure sprayer inspired by the bombardier beetle (12/15/10). So how “simple” is the mechanism? Using intelligent design, his team took five years trying to duplicate it for their invention. McIntosh now travels internationally giving scientific evidence for creation.

Speaking of beetles, another odd one was described recently by New Scientist. One might think the stag beetle would have trouble flying with those long jaws that protrude almost as long as the rest of its body. Actually, the article says, the “stag beetle’s unwieldy jaws are surprising slick in flight.”

Here’s how evolutionists treat creation arguments: they ignore them. Then they offer brief hand-waving speculations to allege how irreducibly complex mechanisms might have evolved. Once you know their strategy, you find it everywhere.