Friday 2 December 2016

Hey Creationists! What Kind Of Kind Is This?

Asian lonhorn, Anoplophora glabripennis
Genome of the Asian longhorned beetle (Anoplophora glabripennis), a globally significant invasive species, reveals key functional and evolutionary innovations at the beetle–plant interface | Genome Biology.

Probably because it was intelligently designed to do just that, the term 'kind' as used by creationists is so nebulous that it can mean whatever they need it to mean. The meaning can change at will according to the audience they are trying to get away with using it on or the debate they are trying to win with tactics because they don't have any evidence.

It's almost perfectly designed to allow word play and subtle changes in debate barely noticeable by an unsuspecting audience.

For example, it can mean more or less what scientists mean by 'species', or it can mean an entire genus, a family, an order or even a class as the need arises. "But it's still the same kind!" is the plaintive little cry of a creationist who has just been shown evidence of the evolution of a new species, or evidence that different families share a common ancestor.

Cat kind, dog kind, bear kind, carnivore kind, bat kind, bird kind, dove kind, mammal kind - any kind of kind you need because what you can't have is evidence of evolution, and so long as the kind doesn't change, evolution can be dismissed as not having happened, because, as any creationist will assure you, evolution means change of kind. And humans are of course an entirely different kind of kind to all the other kinds, so humans can't have evolved - even from other kinds of human.

So, it'll be interesting to see what creationists make of the Asian longhorn beetle.

But surely isn't that just a beetle kind? A kind of beetle just like all the other 500,000 or so other kinds of beetle - which are all the same kind, obviously?

Well, no, apparently. It evolved not by mutation, at least not directly, and it's genome isn't just a variation of that of the other kinds of beetle. The Asian longhorn beetle evolved by incorporating bits of only very distantly related 'kinds' into its genome. It is mostly beetle kind but it is also part fungus kind and part bacteria kind! To try to argue that these are really all the same kind is to reduce the entire Earth biota to a single kind.



Relatively little is known about the genomic basis and evolution of wood-feeding in beetles. We undertook genome sequencing and annotation, gene expression assays, studies of plant cell wall degrading enzymes, and other functional and comparative studies of the Asian longhorned beetle, Anoplophora glabripennis, a globally significant invasive species capable of inflicting severe feeding damage on many important tree species. Complementary studies of genes encoding enzymes involved in digestion of woody plant tissues or detoxification of plant allelochemicals were undertaken with the genomes of 14 additional insects, including the newly sequenced emerald ash borer and bull-headed dung beetle.

The Asian longhorned beetle genome encodes a uniquely diverse arsenal of enzymes that can degrade the main polysaccharide networks in plant cell walls, detoxify plant allelochemicals, and otherwise facilitate feeding on woody plants. It has the metabolic plasticity needed to feed on diverse plant species, contributing to its highly invasive nature. Large expansions of chemosensory genes involved in the reception of pheromones and plant kairomones are consistent with the complexity of chemical cues it uses to find host plants and mates.

Amplification and functional divergence of genes associated with specialized feeding on plants, including genes originally obtained via horizontal gene transfer from fungi and bacteria, contributed to the addition, expansion, and enhancement of the metabolic repertoire of the Asian longhorned beetle, certain other phytophagous beetles, and to a lesser degree, other phytophagous insects. Our results thus begin to establish a genomic basis for the evolutionary success of beetles on plants.

Evolutionary biology has no problem with horizontal gene transfer as a cause of evolutionary change. In fact much of modern bio-engineering is really human-facilitated gene transfer biologically little different to these occasional examples. There are schools of thought that horizontal gene transfer may well have been commonplace in the early stages of evolution and that, although all life now probably shares a common ancestor, that common ancestor might well have had several.

But it's entirely inconsistent with creationist mythology which, even stretching their definition of 'kind' to an absurd point, there is no way a composite species having multiple and diverse genetic ancestors can be forced into this model.

Of course, they could try to get away with the argument that this isn't gene transfer at all but simply an example of their magic designer re-using a previous design. The problem is there are countless examples of where the same thing is done lots of different ways that the only way this can be incorporated into a conscious design model is to assume the designer has an acute form or amnesia which causes it to forget all about its designs when designing something else.

There is a very good example of this in fact, of which the Asian longhorn beetle is an example. What is described in the above paper offers an explanation of how this beetle's evolution overcame the difficulty many animals have with digesting cellulose. Other species, such as famously the termites, as well as many herbivores don't have this solution. They rely on their gut biota to do it for them and have co-evolved elaborate mechanisms to facilitate this. Only a few days ago another research group published findings which appear to show how mice and humans probably also depend on their gut microbiome to process cellulose and supply small molecule derivatives essential for good health. Why didn't creationists' assumed magic creator use the longhorn beetle solution i the form of an assumed re-use of an earlier design?

So come one creationists! Show how this kind of thing can be fitted into your model? What kind is the Asian longhorn; a beetle kind, a fungus kind, a bacterium kind or a different kind of kind altogether. A kind of muddle, maybe?

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