I assume you are referring to Mann's book 1491
He wrote afolloup called 1493
. which expored the good and the bad results of the "Columbian Exchange".
Did you read both?
They are quite good reading although he dwells on the bleedin obvious in several chapters and goes on interminably on few occasions. Other than that theyre pretty good.
It occurs to me that one of the hugest considerations is what happened to the population numbers of Amerind Natives "post 1492" (of course evidence shows that there were many earlier visits by Europeans (and perhaps others)). Still, the large scale social and environmental changes wrought by the European invasion post
Columbus and the effects to World economies need to be explored by scholars as yourself.
I don't think any anthropologists will argue as to how much the Pre -Columbian people groups already living in the Americas had modified theor environments . Climate changes and migration due to population pressures had left excellent evidence of how the Amercas were first settled by several related lines.