Example1: Mosquitos. Back in the 50's, we discovered DDT and began spraying mosquito infested areas with it. It was 99% effective. Several years later, the effectivity was down to about 50%. Why you ask? The mosquitos evolved. See the first applications killed 99% of the mosquitos in the area. The 1% that survived were naturally immune to it's effects - just by pure chance. Well, these 1% - being the only mosquitos left alive, mated and had little mosquitos. Since both parents were immune to DDT, the odds of the offspring being immune, due to genetics, was much higher. After several repeated sprayings, only the mosquitos capable of surviving DDT were left alive. The more they sprayed, the more immune the mosquitos became. They EVOLVED. Example2: is using anti-biotics. When pennecillin was discovered, it destoyed many, many bacteria. Today, it does not have the same effect for the same reasons I stated above. The bacteria that were immune to pennicillin survived and the ones that didn't - perished.
Yes, we understand and accept this ... this is simple survival of the fittest.
The question is ... how does this help to explain the existence of the Bombadier Beetle?
The question is ... how does this help to explain the existence of the Bombadier Beetle? From Bombardier Beetles and the Argument of Design:
- Quinones are produced by epidermal cells for tanning the cuticle. This exists commonly in arthropods. [Dettner, 1987]
- Some of the quinones don't get used up, but sit on the epidermis, making the arthropod distasteful. (Quinones are used as defensive secretions in a variety of modern arthropods, from beetles to millipedes. [Eisner, 1970])
- Small invaginations develop in the epidermis between sclerites (plates of cuticle). By wiggling, the insect can squeeze more quinones onto its surface when they're needed.
- The invaginations deepen. Muscles are moved around slightly, allowing them to help expel the quinones from some of them. (Many ants have glands similar to this near the end of their abdomen. [Holldobler & Wilson, 1990, pp. 233-237])
- A couple invaginations (now reservoirs) become so deep that the others are inconsequential by comparison. Those gradually revert to the original epidermis.
- In various insects, different defensive chemicals besides quinones appear. (See Eisner, 1970, for a review.) This helps those insects defend against predators which have evolved resistance to quinones. One of the new defensive chemicals is hydroquinone.
- Cells that secrete the hydroquinones develop in multiple layers over part of the reservoir, allowing more hydroquinones to be produced. Channels between cells allow hydroquinones from all layers to reach the reservior.
- The channels become a duct, specialized for transporting the chemicals. The secretory cells withdraw from the reservoir surface, ultimately becoming a separate organ. This stage -- secretory glands connected by ducts to reservoirs -- exists in many beetles. The particular configuration of glands and reservoirs that bombardier beetles have is common to the other beetles in their suborder. [Forsyth, 1970]
- Muscles adapt which close off the reservior, thus preventing the chemicals from leaking out when they're not needed.
- Hydrogen peroxide, which is a common by-product of cellular metabolism, becomes mixed with the hydroquinones. The two react slowly, so a mixture of quinones and hydroquinones get used for defense.
- Cells secreting a small amount of catalases and peroxidases appear along the output passage of the reservoir, outside the valve which closes it off from the outside. These ensure that more quinones appear in the defensive secretions. Catalases exist in almost all cells, and peroxidases are also common in plants, animals, and bacteria, so those chemicals needn't be developed from scratch but merely concentrated in one location.
- More catalases and peroxidases are produced, so the discharge is warmer and is expelled faster by the oxygen generated by the reaction.
- The walls of that part of the output passage become firmer, allowing them to better withstand the heat and pressure generated by the reaction.
- Still more catalases and peroxidases are produced, and the walls toughen and shape into a reaction chamber. Gradually they become the mechanism of today's bombardier beetles.
- The tip of the beetle's abdomen becomes somewhat elongated and more flexible, allowing the beetle to aim its discharge in various directions.
Simply because one cannot imagine a natural cause for something does not mean a natural cause does not exist.
"Meddle not in the affairs of dragons, for you are crunchy and taste good with ketchup."