UPDATE on Leviticus 11:1-47

After some more reading, I found a few reasons why God may have chosen that animals that come under specific exceptions might be unclean.  Mainly, the information comes from a commentary, "A Commentary, Critical and Explanatory, on the Old and New Testaments," by Robert Jamieson, A.R. Fusset, and David Brown, dating from 1871.  In their comments on this particular passage, they list two possible reasons for these restrictions: 1) to ensure distinction between the Jews and surrounding nations they were not to co-mingle with, and 2) dietary reasons.  Both make some sense.  Jews were known throughout their history for their distaste for certain foods based on their religious law, and at times of captivity or oppression, even used that distinction as a basis for looking down upon their oppressors.  The fact that they would detest or have a distaste for food their neighbors were eating would provide a barrier for completely assimilating into other nations, no matter how much they might adopt the strangers' habits (which was still not good).  Dietary reasons for excluding certain foods and preparation practices include that these meats or practices may have led to a greater risk of illness and disease amongst a large people living in close quarters.