We talk a lot on this blog about the “nature nurture” debate (I don’t know to what degree it’s really a debate, but we’ll go with it since this is the common term). For a brief primer, one of the central tenets of genetics is that genotype affects phenotype, but not the other way around. In other terms, your DNA influences your looks, your personality, and even the way you act. But if you were to change any of those things (dying your hair, for instance), it would have no effect on your DNA.
Well, this is not a post about how reality might not be so cut and dry. Rather, its about an interesting (albeit somewhat speculative) idea that requires an understanding of the genetic framework as a starting point.
I learned a lot of fascinating things in my college genetics course. If Mendel’s pea-plant re-creation of the British monarchy wasn’t enough (okay, maybe I’m just a nerd and this isn’t that interesting), the incessant flow of digressions and random factoids kept me enthralled. One of the more curious points made was that the only genetically distinguishable people group known today is the Jews. My reaction then was merely “hmm”, and so it remained until earlier this week.
I was reading through Susan Wise Bauer’s book, The History of Ancient Civilization, the other day (again, the nerdiness is undeniable). While reading the chapters on the earliest cultures of Egypt, Mesopotamia, Asia, and the like, I came to the section on the beginnings of another great culture- the Hebrews. In what is probably not a new story to many of you (it certainly wasn’t to me), a man named Abram left Mesopotamia (called Sumer at the time) along with his family in pursuit of the land of Canaan. Abram then encounters the first monotheistic deity, YHVH (commonly pronounced “Yahweh”), who chooses Abram to be the father of a nation.
If you’re at all familiar with the Judeo-Christian tradition, you know that Israel was called by YHWH to be “set apart”- culturally, theologically, and even physically. And among the physical qualities that set Israel apart from her neighbors, none was more frequently mentioned than circumcision.
Bauer shed new light onto this practice for me through the following:
With Abraham, “a new race is created and given a mark; God orders Abraham to circumcise his sons, himself, and his family as a sign of their separateness. Presumably the sign would remind them, at the crucial moment, that they were not to mingle their blood with other races”.
For the first time, I thought back on my genetics professor’s words and had a reaction other than “hmm”. Could it be that the practice of circumcision (and its representation of being “set apart”) was so powerful that it genetically isolated the people of Israel even up to the modern-day Jews? Obviously, the effect of circumcision was probably just the culmination of many ritualistic practices in the Hebrew tradition- and it may be that the broader ethos of Hebrew culture is, in fact responsible. But Bauer’s words, to me, are quite convincing. Is this, then, an instance where nurture truly did influence nature? Did “what they do” actually change, at the level of DNA, “who they are”?