Born in Brooklyn NY, moved to Israel in 1984. I teach and write about Torah topics. Author of "Explorations" on the weekly Parsha and "Emanations" on holidays - both published by Targum/Feldheim http://rabbiarikahn.com
While Jews, especially traditional ones, seem to have an aversion to the concept of evolution, halacha itself, the stuff of which Jewish observance is made, may be seen as evolving. We who accept that Torah is the Word of God, and that the Written and Oral Torah were given to us, through Moshe, are aware that, as new situations arise, halacha adapts – has always adapted - in an evolutionary rather than a revolutionary fashion.
At times, though, catalysts of more dramatic change present themselves: Cataclysms, especially those that cause massive population shifts, tend to impact halachic thinking and action in more discernable increments. Nonetheless, we may say that halacha is impacted and affected, rather than pointing to blatant, obvious "changes." Part of the impact is due to what and how people learn.
Throughout Jewish history, catastrophe has often given rise to the perceived need to collect data, to preserve what runs the risk of being lost. Thus, after the destruction of the First Beit Hamikdash we find the canonization of Tanach. After the destruction of the Second Beit Hamikdash, the Bar Kochva rebellion and Hadrionic persecution, the Mishna emerged in an edited form. After a major earthquake destroyed the north of Israel, the Talmud Yerushalmi was edited. In the wake of the Spanish Inquisition, the Shulchan Oruch emerged. This reaction, which we may call "preservation as a means of self-preservation," is not always immediate, but the pattern of reactive codification and archiving is unmistakable.. [...]