Warning: prepare for a hyperlink BONANZA.
Say what you want about Richard Dawkins, but the meme idea he presented in The Selfish Gene is pure genius. Especially astute was his observation that memes mutate and compete in the same ways as genes, even if their modes of propagation differ.
Religion, the greatest meme in recorded history, is prone to the same indels and evolutionary branchings as genes. For example, consider the image below, which exudes a distinct sense of monophyly; relative to the book of Mark, Luke and Matthew exhibit orthology as well as adaptive radiation.
As shown above, while large portions of Mark exist in both Luke and Matthew, the same proportionality does not apply in reverse; Luke and Matthew contain considerable amounts of unique information not present in Mark. Mark, for instance, begins with Jesus’s baptism and makes no mention of his early life. Luke is the only gospel to contain adoration by shepherds at the Nativity of Jesus, and only Matthew mentions Herod’s “Massacre of the Innocents“.
Given these features of the synoptic gospels, most biblical scholars agree that Mark was probably the earliest (some also hypothesize that it is the most accurate) biblical rendition of Jesus’s life (a hypothesis known as Markan priority). Three hypothetical “lost” texts/oral traditions have also been proposed to explain unique material in Luke and Matthew; these are called Q, M, and L.
The Two-Source Hypothesis
The Two-Source Hypothesis posits that a lost document (called Q) contained the extra material found in Luke and Matthew. If this was indeed the case, Luke and Matthew are fraternally related as progeny unto two parents: Mark and Q. Using literalistic genetic analogies, alleles of Q got passed to Luke that were not passed to Matthew and vice versa. The same is true of Mark, though in lesser extent.
So here’s where things get complicated with regard to the gene-meme analogy. Depending on the source complexity of memes, they can be modeled via genetic or speciation frameworks. Operating within a purely Markan priority model, Luke and Matthew can be seen as offshoot derived species of a common ancestor: Mark. However, by incorporating Q, a species-level representation ceases to be perfectly analogous to traditional, branching cladogenesis. Instead, a form of reticular hybridization presents itself; members of different “species” hybridize to form conglomerate meme offspring–in this case, Luke and Matthew.
The Four Document Hypothesis
A second, more convoluted take on the phylomemy of Luke and Matthew is the Four Document Hypothesis, diagrammed above. Under this model, hypothetical L and M documents or oral traditions contribute unique elements to Luke and Matthew, respectively, in addition to the more common traits derived from Mark and Q. This hypothesis also permits wiggle room for an Antiochian Document and Document of Infancy, which would contribute respectively to Matthew and Luke via reticular hybridization (like everything else here, it seems). When it comes to memes, those that persevere appear to be the amalgamative ones.
Certainly, memes may often survive by hybridizing; however, no single gospel includes all the information contained within Mark, Matthew, and Luke (partly because incredible storytelling discontinuities and other inconsistencies would result). This is where adaptive radiation comes into play; speciation of the parent memes occurs as a result of adaptive necessity.
Back in the day, there wasn’t a single audience for Christian memes, but many, including Romans, Christians, Jews, and other groups. The Gospel of Mark and Gospel of Luke are thought to appeal to the Christian audiences, with Mark serving as a baseline of educational tidbits and Luke as a sort of “expansion pack” that also frames Romans in a positive light. Matthew, by contrast, hearkens strongly to the Jewish cause, poising Jesus as the prophesied Jewish Messiah and portraying his roots in a similar fashion to Moses’s (i.e. the “Massacre of the Innocents” mentioned earlier). The distillation of these three gospels from multiple and reticularly hybridizing parts, it would seem, is a function of broadened environmental adaptability, just as we see in evolutionary biology. The more audiences are appealed to, the more likely meme survival becomes.
Of course, nowadays, memes take on slightly different forms. Evolution is cool like that.