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Saturday, June 24, 2006

A fungus sports a harpoon gun - without a licence

by Denyse O’Leary

A fungus called haptoglossa mirabilis uses a harpoon gun
to attack the rotifer (a microscopic animal) and nematode a simple type of worm that is one of the most common life forms on Earth. (Nematodes survived the destruction of Challenger space shuttle.)

The harpoon injects the reproductive cells (sporidium) of the fungus into the worm, and the junior fungi consume it within the next couple of days. They then germinate to form clusters of gun cells.

According to University of Guelph (Ontario, Canada) researcher George Barron, the technology by which the fungus consumes the nematode is tiny but sophisticated:

The head of the harpoon is laminated. This means that it is compressible. As it is pushed up the barrel of the gun it will fit tightly and prevent leakage to maintain maximum muzzle velocity. As it emerges from the muzzle it pierces the cuticle of the nematode. At the head emerges it will 'decompress' and make a hole wider than the width of the bore. This will facilitate penetration by the everting tubular "hypodermic".

The gun cell is anchored to the substratum by a mucilaginous glue. It also has a swollen base. When the base is anchored the business end of the gun cell is then tilted upwards at an angle of about 30 degrees which is very suitable for contact with the nematodes and rotifers that graze bacteria in the vicinity of the cell.

The basal vacuole is the power pack for the cell. It is at high Osmotic Pressure. When the gun cell is released the pressure up front is removed and water flows in rapidly through the semipermeable membrane surrounding the vacuole. This squeezes the protoplasm and nucleus, like toothpaste, through the tubular hypodermic. The Haptoglossa gun cell is only about 15 microns long.

Just how do life forms such as haptoglossa acquire sophisticated equipment, given that they do not, so far as we know, have intelligence in the human sense? Darwinian evolutionists argue that such technologies evolve through a long, slow process of natural selection. However, a harpoon gun that Haptaglossa needs in order to reproduce itself can hardly wait years for Service Pack 2 before it works properly.

It was questions like this that prompted Gordon Rattray Taylor, a well-known British science journalist in the 1970s, to write a book, published in 1982 shortly after his death, in which he asked some probing questions about the traditional Darwinian explanations. He focused on a different creature that also uses a gun mechanism, as you will see from this excerpt from By Design or by Chance? (Augsburg Fortress 2004. p. 93):

A Mystery of the Natural World A Worm Armed for War

Gordon Rattray Taylor was a well-respected British science writer, and Chief Science Advisor to BBC Television. Shortly before his death in 1981, he completed a book, The Great Evolution Mystery, in which he explained why he questioned Darwinism and neo-Darwinism. He relates, for example, the strange tale of the relationship between the pond hydra (Hydra) and the flatworm Microstomum.

The pond hydra is a tiny creature, shaped like a tube, with a mouth end and a foot end. It proceeds through life by rolling end over end. Some species of hydra hunt and protect themselves with a battery of poison guns: tiny stinging cells mounted on their surface that fire a coiled, poisoned hair, with a second hair serving as the trigger.

The hydra is usually safe from the flatworm, but every so often a flatworm seeks out and consumes a hydra. The worm somehow swallows the hydra’s poison gun apparatus without digesting it, and then positions the guns on its own surface. It uses the guns for its own protection; one species actually fires them like rockets at assailants.

As long as the flatworm has ammunition from a previous meal, it ignores hydras. However, when it is low on ammunition, it finds another hydra, eats it, and repeats the cycle.

Taylor asks how a creature with no brain or complex nervous system learns this routine. How does it remember and pass it on? He writes: "The theory of evolution by natural selection is powerless to explain how chance variation could have evoked such a closely coordinated programme."

Taylor believed that evolution occurs, and he also believed that random natural selection played a role in evolution. However, he came to doubt Darwinism, the idea that random natural selection and a few other naturalistic processes explain the life we see around us. Rather, he argued that "we seem to see a purposiveness of the kind which Darwinists refuse to believe in."* Taylor did not believe that this purposiveness—or purpose—was part of a divine plan. He thought it was implicit in the nature of life itself.

Whether the purpose Taylor spoke of resides in the nature of life itself or in something beyond life, many today find it increasingly difficult to ignore—which is why the intelligent design controversy has become so fierce .

(*See Gordon Rattray Taylor, The Great Evolution Mystery (London: Secker & Warburg, 1982), pp. 14–15.For microstomum, search at.)

Toronto-based Canadian journalist Denyse O’Leary (www.designorchance.com) is the author of the multiple award-winning By Design or by Chance? (Augsburg Fortress 2004), an overview of the intelligent design controversy. She was named Recommended Author of the Year in 2005 and is co-author, with Montreal neuroscientist Mario Beauregard, of the forthcoming The Spiritual Brain (Harper 2007).

If you like this blog, check out my book on the intelligent design controversy, By Design or by Chance?. You can read excerpts as well.

Are you looking for one of the following stories?

A summary of recent opinion columns on the ID controversy

A summary of recent polls of US public opinion on the ID controversy

A summary of the Catholic Church's entry into the controversy, essentially on the side of ID.

O'Leary's intro to non-Darwinian agnostic philosopher David Stove ?

An ID Timeline: The ID folk seem always to win when they lose.

O’Leary’s comments on Francis Beckwith, a Dembski associate, being denied tenure at Baylor.

Why origin of life is such a difficult problem.

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