Friday, December 4, 2009

Sin, Evolution, and Parasites

"…And God saw every thing that he had made, and, behold, it was very good."

What would He say today? Is everything we see around us the way it was created in the Garden of Eden? Did He create a plant that can only get the nitrogen it needs by eating insects? Did He give wasps, jellyfish, and nettles their sting? What about parasitic organisms did He make them?

Consider one of the beautiful creatures from the Garden of Eden – the serpent. This creation which was beautiful before the fall, was cursed of God (Genesis 3:14) and thereby changed drastically in esteem, behavior, and, quite likely, morphology as well.

I have come to think of this as an example of the effects that sin can have even in a very short amount of time. It has also caused me to postulate that the presence of sin in the world causes directional selection away from God’s ideal. In addition, once the original creation was altered and became unbalanced, natural selection would also have been free to work thus exacerbating the problem and quickly steering life on this earth away from God’s plan at an ever increasing rate. As evil forces in the world continued to focus their influence to mar Gods creation it would not be unreasonable to expect results significantly different from what God would have created.

It seems that every “free living” species in the world today has at least a couple (and often dozens or hundreds) of parasitic species that live on or in it… and many of those parasites are parasitized themselves such that there can be several levels of parasites parasitizing other parasites. Not only are they the most plentiful creatures on earth but they cause an incalculable amount of suffering and death. What’s more is that they have some of the most intricate life cycles imaginable. Many parasites require development in two, three or even four different hosts often requiring unlikely events to pass from one stage of development to the next before they reach maturity.

One notable parasite, the lancet liver fluke, begins development only when eaten by a snail. Later, the young parasites are left behind the snail in its trail of slime as a little ball of mucus filled with juvenile parasites. To continue development this ball of slime must be eaten by an ant at which point one or two of the juveniles migrate to the brain where they alter the ants’ behavior while the others continue development in the ant. The altered behavior of the ant causes it to climb to the top of a plant during the night and hold on tightly with its jaws instead of going back to its colony. This allows it to be accidentally eaten by a browsing animal where the parasites complete development and pass their eggs on to start a new generation.

Another example is Trichenella spiralis (the cause of trichinosis) which can only pass to the next host when the flesh of an infected animal is eaten after which point the parasites invade cells in the new host and, much like a virus, hijack host cells causing them to do nothing but aid in the proliferation of more parasites.

Although it could be argued that some parasites may have originally been beneficial symbiotic organisms, much like some of the bacteria in our digestive tract. Many parasites, including the ones mentioned above, must have evolved not only their pathogenicity, but also their life cycle after sin entered the world. These evolutionary steps are larger than those I would have previously condoned (such as a fox learning to eat squirrels in addition to strawberries). Yet, due to the direction of changes that have been made away from their state in the Garden of Eden towards a more misery-causing state, I think I may know the culprit of what seems to be a significant amount of change.

Note: I am not suggesting that I know the degree to which any form of evolution has occurred in the history of our earth nor whether or not some change (gradual or otherwise) would have happened in the absence of sin – the thoughts above are merely some ideas of how it “may have been”