Today is the 200th birthday of Charles Darwin, so it’s a good day to blog about him.
The idea that natural (or artificial) selection can introduce changes in a species is not controversial. After all, even hard-core six-day creationists like me believe that both Vikings and Bushmen are descended from Adam and Eve, and we all know that the different breeds of dogs come from wild dogs or wolves, so we can allow for a species to change somewhat to adapt to its environment.
But that doesn’t mean natural selection explains how we got here. Some creatures and processes that we see go against the rules of natural selection.
There are quite a few species of these slightly crazy creatures. They will set up a cleaning station, and wait for host fish to come to them for a cleaning. (Other cleaner fish make “house calls.”) They eat the dead skin and parasites off of the host fish, and will sometimes even clean the teeth of predators. The predators recognize them by color and don’t eat them, even though some of them will cheat and munch a scale or two. Predators will pose in an unnatural way, signaling that they are not a threat, and will even let the cleaner fish into their mouths and gills.
For this symbiosis to occur, there must be a previous understanding. The large predatory fish needs to “know” that it is beneficial for a small fish to nibble it, and it needs to resist the temptation to bite back. Getting humans to the dentist is hard enough. Meanwhile, the small cleaner fish has to go against all natural instincts to avoid predators, and has to set up a “business” much like a dental hygienist. It has to “know” that it won’t be eaten.
The creationist has no problem with this symbiotic arrangement, but “natural selection” does not explain the origin of this behavior very well. The first cleaner fish had to be suicidal, and the first host fish had no way of knowing that a cleaning would be beneficial.
2. Bombardier Beetles
Skunks repel predators with their scent glands, which are similar to other animals’ scent glands, but a whole lot nastier.
Bombardier Beetles have a whole chemistry lab in their behinds, and can shoot benzoquinones at 100 degrees C, pulsing 20 times per second, at a range up to 20 cm. They can rotate the direction of their spray 270 degrees, so a predator can’t attack them from a “safe side”. Their spray mechanism is being studied and imitated to improve spray technologies. It requires a lot of creativity to explain how the spray mechanism could have evolved by time plus chance, plus natural selection.
3. Archer Fish
The Archer Fish spits a stream of water to shoot down insects and small animals at ranges up to 1.5 meters. They develop their skills as they grow, and are able to compensate for gravity and the refraction of light as it goes from air to water. They also conserve energy by adjusting the power of the jet to the size of the target. All that spitting takes a lot of energy.
The problem with this skill evolving is that for this skill to be useful, it has to work right away. Otherwise we have thousands or millions of years of pointless spitting until the mouth of the archerfish, plus its eyesight, plus its behavior all combine to make the spitting into a useful skill. A series of gradual changes doesn’t work too well here.
4. Sexual Reproduction
It’s easy to understand why we keep doing it, but it is not obvious how it got started.
For sexual reproduction to get started, you need a male, and a female, of the same type, at the same time, close enough to each other, and they have to like each other. (Perhaps there was this singles’ bar 1.2 billion years ago…) For the system to work, a lot of things have to come together at once, or you have a colossal waste of biological energy.