Unintelligent Design News - What on Earth is This Complex System For?

Lizard beetles, Doubledaya bucculenta, plant a fungal garden inside dead bamboo stems to feed developing larvae.

Credit: Wataru Toki

Nagoya University Research Achievements

The thing about good design is that the thing designed should have a clear purpose. Simply making things that don't do anything except make copies of themselves is not the act of an intelligent designer, and there are some complex systems and processes in nature that should leave any intelligent [sic] design advocate scratching their head and wondering what on Earth the purpose of this is and why does it need to be so complicated?

Of course, nothing in the living world has any ultimate purpose other than making copies of itself (which is just one of the ways we know it isn't intelligently designed). So, Creationists go on to make up all manner of reasons, or assert that it's not given to us to understand the purpose of their putative magic creator, which illustrates the utter uselessness of ID as an alternative scientific hypothesis!

So it would be interesting to hear what Creationists think the purpose of this fungus-farming beetle and its bizarre reproductive system is for, and why it needs to be so complicated?

Briefly, Japanese Lizard beetles, Doubledaya bucculenta, farm yeast inside bamboo stems for their developing larvae to eat. The larvae feed on yeast injected from their mothers' abdomens into the bamboo stems they are growing in. The female beetle has a special structure in her abdomen in which to keep the fungus, which she then injects into dead bamboo shoots along with her eggs. The bamboo supplies the fungus (a type of yeast, Wickerhamomyces anomalus) with nutrients and the growing beetle larvae eat the fungus.

Now, that might seem like a sensible arrangement as the beetle larvae live safe inside the hard bamboo and get a self-renewing food supply and the fungus gets somewhere safe in which to live and reproduce, albeit at a cost. However, two Japanese scientists from Nagoya University have made a surprising discovery. Unlike most fungal-insect symbiotic relationships where the fungus breaks down large and otherwise indigestible polysaccharide molecules such as the cellulose and lignin of which the bamboo is composed, W. anomalus digests small molecules such as glucose and fructose, which the beetle larvae could do for themselves.

This was a real surprise. While yeast can indeed decompose those indigestible components, our analysis shows the yeast actually grows on small molecule monosaccharides.

Bamboo is not only a farm for the yeast but also a house for the larvae. So the larvae can live in a strong house safely because the house is not decomposed by the food.

Wataru Toki.
Graduate School of Bioagricultural Sciences
Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi, Japan

And that's not all. The same scientists also found that the fungus could digest cellulose, etc, since it has the necessary enzymes, but does not do so.

What the scientists propose is that this evolved to prevent the fungus from digesting the bamboo which protects both it and the beetle larvae, the adults of which it needs to perpetuate itself.

So, we have a fungus provided for the larvae to eat, but they do so by digesting the same sugars that the larvae could digest themselves without all the intermediate machinery the fungus uses, and this is all to prevent the yeast digesting the plant it and the larvae are housed in. Any sane designer who ended up with a beetle needing somewhere safe to lay its eggs, so its larvae were protected and fed, would have just created the larvae to eat the glucose and fructose the fungus eats and cut out the middleman. The larvae's inability to digest the structural polysaccharides would have prevent it from destroying its protective housing.

And that would be assuming there was some purpose for these beetles beyond making more lizard beetles.

The scientist's findings were published in Scientific Reports last September:

Abstract
Symbiotic fungi of wood-inhabiting insects are often considered to aid wood digestion of host insects when the associated fungi can assimilate wood-associated indigestible materials. In most cases, however, the components of wood that are utilized by fungal symbionts remain poorly understood. The lizard beetle Doubledaya bucculenta (Coleoptera, Erotylidae, Languriinae) farms the symbiotic yeast Wickerhamomyces anomalus inside the cavity of host bamboo internodes, which serves as food for larvae. To determine the carbon sources of the internodes serving as nutritional substrates for W. anomalus, we used ion exchange chromatography measurements to analyze free and structural sugar compositions in fresh pith (FP), yeast-cultured pith (YP), and larva-reared pith (LP) of internodes. Glucose and fructose were the major free sugars in FP and markedly decreased in YP and LP. For structural sugars, no sugar significantly decreased in YP or LP compared with FP. Carbon assimilation tests showed that W. anomalus assimilated glucose, mannose, fructose, and sucrose strongly, xylose and cellobiose moderately, and xylan weakly. Elemental analysis revealed that the compositions of carbon, hydrogen, and nitrogen were not significantly different among tissue types. These results suggest that W. anomalus does not consume bamboo-associated indigestible sugars but most free sugars, mainly glucose and fructose, in the pith. Our findings suggest that a symbiont’s abilities may not always benefit its host in nature.

Toki, W., Aoki, D.
Nutritional resources of the yeast symbiont cultivated by the lizard beetle Doubledaya bucculenta in bamboos.
Scientific Reports 11, 19208 (2021). DOI: 10.1038/s41598-021-98733-y

Copyright: © 2021 The authors. Published by Springer Nature Ltd.
Open access
Reprinted under a Creative Commons Attribution 4.0 International license (CC BY 4.0)

It would be hard to think of a better example of a system which violates all the principle of good design. Firstly we have no clear purpose; secondly, we have needless complexity and thirdly, we have prolific waste in that an intermediate of that complexity in the larvae’s food chain is inevitably wasteful and many more beetles could be produced without it.

And then, of course, the inexplicable stupidity of using a fungus with all the enzymes needed to digest cellulose, then not using them because doing so would destroy the entire system!
There are very many more of these examples in my book, The Unintelligent Designer: Refuting the Intelligent Design Hoax, but few of them are so starkly examples of the sort of stupidity in design that can only come from an unintelligent, undirected, mindless, natural process such as evolution by natural selection, so it is hard to think of a system which doesn't refute the notion of intelligent design quite so comprehensively.

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