Allowing for around 8 years of travel through the wilderness to Bountiful, we have a culture now nearly over 170 years old in the New World. After that length of time, they were no longer a transplanted Old World colony. Jacob's apparent advanced age when he died suggests that Jacob may have been the last of the community born in the Old World. From this point in time on, we are surely dealing with a culture that is now a New World culture, with adaptations to the climate and foodstuffs, and certainly contact with the other extant towns/cultures around them.
While a subtle theme rather than an explicit one, this interaction with other established cultures, and the borrowing or assimilating of physical and perhaps ideological culture from those other peoples will run as a sub-current under the text of the Book of Mormon, just as the religion of Canaan runs as a traceable but faint sub-stream under the Old Testament.