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Biological traps

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One of the favorite arguments of the ID movement is irreducible complexity, and one of the favorite examples of IC is the standard snap mousetrap. Various efforts have been made to (1) reduce the mousetrap or (a different matter) (2) show how a mousetrap could "evolve" gradually, using for-the-sake-of-argument assumptions like allowing mousetrap replication and mutation.

These examples are only likely to convince the already converted due to the artificiality of the example and the substantial disanalogies between mousetraps and biological systems. However, the evolution of carnivorous plant traps and other biological traps, which are both legitimately biological and legitimate analogs of the human-constructed mousetrap, serve as excellent rebuttals to Behe's claims.

Background links on ID and mousetraps

Human-designed mousetraps

Intelligent Design and Mousetraps

Examples of Biological Traps (need pics and intros)

Carnivorous plants

An excellent overview of carnivorous plants in general, with many excellent pictures, is available at The Carnivorous Plant FAQ. See also the International Carnivorous Plant Society Homepage

References on the evolution of carnivorous plant traps

  1. Darwin, Charles (1875). Insectivorous plants. New York, D. Appleton. Web Link.
  2. Juniper, B. E. (1986). The path to plant carnivory. Insects and the Plant Surface. Juniper, B. E. and Southwood, T. R. E., Eds. London, Edward Arnold: 195-218.
  3. DeGreef, John D. (1988). The evolution of Aldrovanda and Dionaea traps. Carnivorous Plant Newsletter. 17(4): 119-125.
  4. Givnish, Thomas J. (1989). Ecology and evolution of carnivorous plants. Plant-Animal Interactions. Abrahamon, W. G., Ed. New York, McGraw-Hill Book Company: 243-290.
  5. Juniper, B. E., Robins, Richard J. and Joel, D. M. (1989). The Carnivorous Plants. London; San Diego, Academic Press.
  6. Cook, Steve R. (2001). �When plants kill.� Accessed online: October 10, 2001. Web Link.
  7. Cameron, Kenneth M., Wurdack, Kenneth J. and Jobson, Richard W. (2002). Molecular evidence for the common origin of snap-traps among carnivorous plants. American Journal of Botany. 89(9): 1503-1509. Web Link.
  8. New York Botanical Garden (2002). �Garden scientists answer a long-standing question about carnivorous plant evolution.� Accessed online: June 15, 2003. Web Link.
  9. Muller, Kai, Borsch, Thomas, Legendre, Laurent, Porembski, S. and Barthlott, W. (2002). From defense to attack: Evolution of carnivory in the Lamiales. Symposium 30: Pflanzensystematick/Biodiversitaet. Web Link.
  10. Jobson, Richard W., Playford, Julia, Cameron, Kenneth M. and Albert, Victor A. (2003). Molecular Phylogenetics of Lentibulariaceae Inferred from Plastid rps16 Intron and trnL-F DNA Sequences: Implications for Character Evolution and Biogeography. Systematic Botany. 28(1): 157�171. BioOne PDF Journal.
  11. Muller K, Borsch T, Legendre L, Porembski S, Theisen I, Barthlott W. (2004). "Evolution of carnivory in lentibulariaceae and the lamiales." Plant Biology (Stuttg) 6(4):477-90. PubMed Journal DOI
  12. Dunkelberg, Peter (2003). Irreducible Complexity Demystified, Venus Flytrap section. URL: http://www.talkdesign.org/faqs/icdmyst/ICDmyst.html#venus

Ant Lion traps

References on the evolution of ant lions

  1. Eisner, T., I. T. Baldwin, and J. Conner. (1993). Circumvention of prey defense by a predator: Ant lion vs ant. Proc. Natl. Acad. Sci. USA 90: 6716-6720. PubMed
  2. Mansell, M.W. (1996). Predation strategies and evolution in antlions (Insecta: Neuroptera: Myrmeleontidae). In: Canard, M., Asp�ck, H. & Mansell, M.W. (Eds). Pure and Applied Research in Neuropterology. Proceedings of the Fifth International Symposium on Neuropterology, Cairo, Egypt, (1994. 161-169. Sacco, Toulouse.
  3. Mansell, M.W. (1996). Unique morphological and biological attributes: the keys to success in Nemopteridae (Insecta: Neuroptera). In: Canard, M., Asp�ck, H. & Mansell, M.W. (Eds). Pure and Applied Research in Neuropterology. Proceedings of the Fifth International Symposium on Neuropterology, Cairo, Egypt, (1994. 171-180. Sacco, Toulouse.
  4. Mansell, M.W. (1999). Evolution and success of ant-lions (Neuropterida: Neuroptera, Myrmeleontidae). Stapfia 60: 49-58.
  5. Mansell, M.W. & Erasmus, B.F.N. (2001). Southern African biomes and the evolution of Palparini (Insecta: Neuroptera: Myrmeleontidae). Proceedings of the Seventh International Symposium on Neuropterology. Budapest, Hungary. August 2000. (In press).

Angler fish lures

Anglerfish lure their dinner, rather than a free ride for their larvae [as in the lures of the clam Lampsilis]. They carry a highly modified dorsal fin spine affixed to the tips of their snouts. At the end of this spine, they mount an appropriate lure. Some deep-sea species, living in a dark world untouched by light from the surface, fish with their own source of illumination: they gather phosphorescent bacteria in their lures. Shallow-water species tend to have colorful, bumpy bodies, and look remarkably like rocks encrusted with sponges and algae. They rest inert on the bottom and wave or wiggle their conspicuous lures near their mouths. "Baits" differ among species, but most resemble -- often imperfectly -- a variety of invertebrates, including worms and crustaceans.

Pietsch and Grobecker's anglerfish, however, has evolved a fish lure every bit as impressive as the decoy mounted on Lampsilis's rear -- a first for anglerfish. (Their report bears as its appropriate title, "The Compleat Angler" and cites as an epigraph the passage from Walton quoted above.) This exquisite fake also sports eyelike spots of pigment in the right place. In addition, it bears compressed filaments representing pectoral and pelvic fins along the bottom of the body, extensions from the back resembling dorsal and anal fins, and even an expanded rear projection looking for all the world like a tail. Pietsch and Grobecker conclude: "The bait is nearly an exact replica of a small fish that could easily belong to any of a number of percoid families common to the Philippine region." The angler even ripples its bait through the water, "simulating the laterial undulations of a swimming fish."


The only thing more difficult to explain than perfection is repeated perfection by very different animals. A fish on a clam's rear end and another in front of an anglerfish's nose -- the first evolved from a brood pouch and outer skin, the second from a fish spine -- more than doubles the trouble. I have no difficulty defending the origin of both "fishes" by evolution. A plausible series of intermediate stages can be identified for Lampsilis. The fact that anglerfish press a fin spine into service as a lure reflects the jury-rigged, parts-available principle that made the panda's thumb and the orchid's labellum speak so strongly for evolution (see the first essay of this trilogy). But Darwinians must do more than demonstrate evolution; they must defend^ the basic mechanism of random variation and natural selection as the primary cause of evolutionary change. (Gould 1980, pp. 35-37)

Anglerfish are sit-and-wait predators. Highly camoflagued, they sit on the bottom and attract prey with a modified spine that acts as a lure. The lure often resembles a small fish or other prey item.

http://www.ultranet.com/~jkimball/BiologyPages/A/anglerfish100.jpg Anglerfish

Kimball's Biology Pages says,

The angler fish (Antennarius) displays a lure resembling a small fish. The lure is a development of the spine of the first dorsal fin. This species of anglerfish, which was found in the Philippines, is 9.5 cm long. Note its use of camouflage: its texture (and color) closely resemble the sponge- and algae-encrusted rocks found in its habitat.

Web searches turn up endless pages of creationist drivel on the angler fish, but persistence pays off:

You can see how this kind of adaptation could get started when you look at a species like this, which has lots of spines that aren't lures, and one that is a lure but not a particularly fantastic one:

From there they can lose the rest of the spines...

...and a heck of a lot uglier, this thing looks like it's from a horror movie...

(note also another interesting feature of some species of deep-sea anglerfish, the fact that the male is tiny and mates by biting the female and eventually getting permanently attached as a kind of parasitic little sperm bank for the female...yet another example of the common biological trend of "being a male sucks", another thing that evolution explains nicely but where design is left hapless)

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