Okay, this title is going to take some explaining. It comes from a web link publicized by Science magazine.
Apparently, until about 1000 CE, the Catholic Church did not make a big deal about eating meat on Fridays and certain holidays. But after that time, probably as a direct result of the papal edict, there was a market for chickens. Farmers bred chickens that were plumper and which laid eggs all year long rather than just seasonally. These characteristics are associated with a gene variant known as thyroid stimulating hormone receptor (TSHR), which is now found in virtually all commercial chickens. Archaeologists (for whom DNA sequencing is now a standard tool) sampled twelve sites in Europe ranging from 280 BCE to the eighteenth century and found that the TSHR allele was rare in chickens before about 1000 CE.
Is it too much of a stretch to say that the whole modern chicken industry exists as a result of papally-enforced religious dogmas from a thousand years ago? Just remember the Law of Unintended Consequences: this is certainly not what the Catholic Church was trying to do.