Why 20 Primarchs...Not Zodiac
I have been reading a lot of discussion about the reasons why there were 20 Primarchs created by the Emperor and it seems that everyone suggests it has something to do with the zodiac.
I believe the number 20 is more scientific than that for several reasons. First, the Emperor is not only the greatest psyker ever, but the greatest scientist ever too. Sure he has a discussion with young Lupercal about the Taurus in HR but that is just an illusion to what the Emoeror wants him to become. Second, no matter what culture you look to there is always a question of which Primarch matches to which constellation. Finally if you look up the number 20 from a scientific point of view it is very easy to see why were 20 Primarchs created.
HERE WE GO...
Proteinogenic amino acids-these are the basic mechanisms for the construction of the human body. Of the 22 of these there are 20 that are directly encoded into the Universal Genetic Code (which makes an appearance in the newest Deleiverence Lost novel when Corax enters the Hall of Victory on Terra).
The Universal Genetic Code is the set of rules by which information encoded in genetic material (DNA) is translated into proteins by living cells.
The reason the Primarchs are greater than homo-sapiens is because their genetic base is taken from the Emperor who is basically a living god. In Prospero Burns they talk about how each of the Primarchs was built to fulfill a specific purpose by the Emperor and is further discussed in the DL novel as Corax and the Tech priest break down the Primarch Genetic Material. They see that some pieces the Universal Code have been taken away and replaced with other pieces of genetic material (the sixth has Animal DNA in it). As I said before the Emperor created each primarch for a purpose so, The E must have personally manipulated the 20 Amino Acids to create 20 DIFFERENT Men from ONE source of DNA.
This theory makes much more sense that trying to associate the Primarchs with astrological signs that ancient men dreamed up when there was little scientific understanding of the Universe surrounding them.
I think this also is the reason why there are two missing Primarchs. It would seem possible that the changes the Emperor made to the genetic code would have unforeseeable results. Two of them probibly succombed to sort of mutation or genetic damage as a result and thus eradicated erased or destroyed because of it. Sure it allows people to create their own chapter but that would be entirely possible to create other Chapters of Astartes without needing to have the two missing Legions, there were many foundings and there were many more strands of progenoids created after the heresy.
Tried to keep it short. Anyone? Hello?