Parasites are degenerations of free-living species (Talk.Origins)
- Parasites are degenerate forms of free-living or mutualistic organisms. They became parasites when something went wrong as a result of the Fall. For example, the parasite came to invade the wrong host or the wrong organ within the host, or it changed to harm the host where it did not before.
Source: Mace, Stephanie R., B. A. Sims, and T. C. Wood, 2003. Fellowship, creation, and schistosomes. Impact 357.
There is no reference in the article to parasites being degenerate forms of free living organisms. The idea presented is that they originally were mutualistic. (Talk.Origins quotes in blue)
1. Parasites are far from degenerate. They have lost features that are familiar to us as nonparasites, but they also have acquired many other highly sophisticated features and abilities, allowing them to find their hosts, to survive their hosts' immune systems (often multiple hosts for one parasite), and to survive some otherwise hostile environments within their hosts. Creationists themselves tout the complexity of the immune system; does not circumventing an immune system deserve at least as much credit? Fast-evolving viruses like the common cold show that such adaptations are evolving all the time.
This extends naturally from the theory that they are degenerate forms of mutualistic organisms, as these factors would be just as important to a mutualistic organism.
Here are just a few features that parasites have. Similar adaptations are common:
- Sacculina, a parasitic barnacle, infests crabs. It prevents the crab from molting and reproducing and induces the crab to care for the parasite's brood as if it were the crab's. Even male crabs are feminized to groom as if they had a female's brood pouch
- The larva of the Hymenoepimecis wasp parasitizes an orb-weaving spider. When the larva is ready to pupate, it modifies the spider's behavior to make it spin a cocoon for the wasp.
- The fungus Entomophthora muscae infects and kills house flies, but before it kills them, it manipulates the fly's behavior to make it crawl to a high place and adopt a sexually receptive pose, behaviors that increase the likelihood of the fungus spreading to other flies.
Each of these; excluding the present harm; could have had a pre fall benefit to the host, but since it has been lost it may not be possible to figure out what it was. These aspects however do however show design.
2. Evolution often goes the other way; parasites that initially are very harmful become more benign to their host over time. The virulence of a pathogen is generally predictable on the basis of evolutionary principles.
Creationists recognize that organisms can adapt, and this is equally predicted by the creationists' view of adaptation.
For example, parasites are less virulent at low host population densities where the parasites risk destroying available hosts and themselves with them.
This actually speaks of deign, it is a God given mutual defense mechanism and it actually supports the idea that parasites where once mutualistic organisms.
3. Why do organisms have defenses against pathogens in the first place? They would not have been needed in a pre-Fall world without pathogens, and their complexity and effectiveness show that features such as immune systems are not degenerate forms themselves.
- Such immune systems could have served to protect organisms against accidental infection of the wrong host by a mutualistic organism, as such it would have done the job perfectly.
- Such immune systems could have resulted from post Fall genetic re-engineering by God.
In both cases present immune systems would be degenerate forms of far more effective immune systems.