Memeplex

Much of the study of memes focuses on groups of memes called meme complexes, or "memeplexes." Like the gene complexes found in biology, memeplexes are groups of religious, cultural, political, and idealogical doctrines and systems. Some selfish genes propagate more effectively together, and similarly some memes propagate more effectively together. Examples include sets of beliefs like acupuncture and astrology, sets of traditions like Christmas celebrations, the relationship between Capitalism and Christianity, circumcision, languages, political ideologies, religions and scientific theories.

These conceptual memeplexes can be true and useful or false and harmful to the mind carrying them, and both useful and harmful memeplexes are able to self-propagate. Different memes in a memeplex can interact to reinforce each other, and it is thought that different memeplexes can work either against or with each other, perhaps also altering their consistency by absorbing or ejecting particular memes as their usefulness is proven or disproven. This process is not yet fully understood, but a model like that of natural selection may be useful in understanding the behavior of memeplexes. Philosopher Daniel C. Dennett and evolutionary biologist Richard Dawkins have spoken publicly on this subject. 

Religion
Memeplexes have been employed recently in attempts to understand religion. In the case of Christianity, the idea suggests, the Christian memeplex "evolved" based upon the Jewish religious teachings, among others, to eventually form the Catholic church, followed by various schisms leading to the Eastern Orthodox churches and various Protestant churches. In this process, various theologians, political leaders, writers, and religious visionaries have added and deleted individual memes from the Christian memeplex resulting in the formation of new but related memeplexes, or (religions/sects). The process of schism, like evolution, is ongoing, and as a result smaller and less differentiated memeplexes have arisen within the Catholic, Orthodox, and Protestant traditions. The same process could be said to be occurring in the case of many sets of belief.