These ideas are usually expressed, in Anthropology, as "Transfer of Technology versus Independent Invention."

The development of glassmaking and glassworking are prime examples of the controversies surrounding such ideas—informing anyone interested in the topic that there are two camps, and two groups of people on each side.

One groups says, "glass was independently devised in more than one place, but then disseminated elsewhere in antiquity."

The other group says "glass was invented one time, had one source, and was disseminated from that time and place in antiquity."

I can tell you who published the second idea. This was Samuel Kurinsky—with whom I carried on considerable correspondence in the 1990s. I reviewed his book for Ornament. And I met him when he lectured for the Bead Society in Los Angeles. He is now deceased.

I suppose there are various authorities in the opposite camp. But, as far as I know, no one has composed a tome that purports to elucidate a comprehensive theory of multiple inventions/developments and disseminations.

Nevertheless, the people who are in one camp or the other think the opposite camp is mistaken.

I have discussed these ideas a number of times in the past. At the Beads-L online Group (that was hacked and disappeared); and at the previous iteration of BeadCollector Forum. Both of which were before your time of bead-collecting and interest.

Jamey