Claim CB310:
The bombardier beetle cannot be explained by evolution. It must have been
designed.
Source:
AIG, 1990. The amazing bombardier beetle. Creation Ex Nihilo
12(1): 29.
Gish, Duane T., 1977. Dinosaurs: Those Terrible Lizards. El
Cajon, CA:
Master Book, pp. 51-55.
Response:
- This is an argument from incredulity. It is
based in
part on an inaccurate description of how
the beetle's
bombardier mechanism works, but even then the argument rests solely on
the lack of even looking for evidence. In fact, an evolutionary
pathway that accounts for the bombardier beetle is not hard to come up
with (Isaak 1997). One plausible sequence (much abbreviated) is thus:
- Insects produce quinones for tanning their cuticle. Quinones make
them distasteful, so the insects evolve to produce more of them
and to produce other defensive chemicals, including
hydroquinones.
- The insects evolve depressions for storing quinones and muscles for
ejecting them onto their surface when threatened with being
eaten. The depression becomes a reservoir with secretory glands
supplying hydroquinones into it. This configuration exists in many
beetles, including close relatives of bombardier beetles (Forsyth
1970).
- Hydrogen peroxide becomes mixed with the hydroquinones. Catalases
and peroxidases appear along the output passage of the reservoir,
ensuring that more quinones appear in the exuded product.
- More catalases and peroxidases are produced, generating oxygen and
producing a foamy discharge, as in the bombardier beetle Metrius
contractus (Eisner et al. 2000).
- As the output passage becomes a hardened reaction chamber, still
more catalases and peroxidases are produced, gradually becoming
today's bombardier beetles.
All of the steps are small or can be easily broken down into smaller
ones, and all are probably selectively advantageous. Several of the
intermediate stages are known to be viable by the fact that they exist
in other living species.
- Bombardier beetles illustrate other aspects of life that look
undesigned:
- With design, we expect similar forms to be created for similar
functions and different forms for different functions (Morris 1974, 70).
However, what we see is different forms for similar functions. Many
ground beetles have very similar habits and habitats as centipedes,
but their forms differ greatly. Different groups of bombardier
beetles use very different mechanisms for the same function of aiming
their spray (Eisner 1958; Eisner and Aneshansley 1982).
- Some forms have no function. Some bombardier beetles have vestigial
flight wings (Erwin 1970, 46,55,91,114-115,119).
- If bombardier beetles have a purpose, then death is an integral part
of it, since the beetles are predators (some, as larvae, are
parasitoids, gradually eating pupae of other beetles [Erwin 1967]),
and their spray is a defense against other predators. Many
creationists claim that death was not part of God's design.
Links:
Isaak, Mark, 1997. Bombardier beetles and the argument of design.
http://www.talkorigins.org/faqs/bombardier.html
References:
- Erwin, Terry L., 1967. Bombardier beetles (Coleoptera, Carabidae) of North
America: Part II. Biology and behavior of Brachinus pallidus Erwin
in
California. Coleopterists' Bulletin 21: 41-55.
- Erwin, Terry L., 1970. A reclassification of bombardier beetles and a
taxonomic revision of the North and Middle American species (Carabidae:
Brachinida). Quaestiones Entomologicae 6: 4-215.
- Eisner, T., 1958. The protective role of the spray mechanism of the
bombardier beetle, Brachynus ballistarius Lec. Journal of Insect
Physiology 2: 215-220.
- Eisner, T. and D. J. Aneshansley, 1982. Spray aiming in bombardier
beetles: jet deflection by the Coanda effect. Science 215: 83-85.
- Eisner, T., D. J. Aneshansley, M. Eisner, A. B. Attygalle, D. W.
Alsop and J. Meinwald, 2000. Spray mechanism of the most
primitive bombardier beetle (Metrius contractus).
Journal of Experimental Biology 203: 1265-1275.
- Forsyth, D. J., 1970. The structure of the defence glands of the
Cicindelidae, Amphizoidae, and Hygrobiidae (Insecta:
Coleoptera). Journal of Zoology, London 160: 51-69.
- Morris, Henry M., 1974. Scientific Creationism, Green Forest, AR: Master
Books.
Further Reading:
Weber, C. G., 1981. The bombardier beetle myth exploded.
Creation/Evolution 2(1): 1-5.
Angier, N., 1985. Drafting the bombardier beetle. Time (Feb. 25),
70.
created 2001-2-17, modified 2004-2-19