https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0298896

Abstract

Starch residue analysis was carried out on stone tools recovered from
the bottom layer of the Anakena site on Rapa Nui (Easter Island). These
deposits have been dated to AD 1000–1300 AD and so far, represent the
earliest evidence of human settlement on this island. Twenty obsidian
tools were analyzed. Analysis of 46 starch grains recovered from 20
obsidian tools from the earliest dated level of the Anakena site on Rapa
Nui provides direct evidence for translocation of traditional crop
plants at initial stages of the colonization of this island. The
analysis of starch grains was based mainly on statistical methods for
species identification but was complemented by visual inspection in some
cases. Our results identify taxons previously unknown to have been
cultivated on the island, such as breadfruit (Artocarpus altilis),
Zingiber officinale (ginger), and starch grains of the Spondias dulcis
and Inocarpus fagifer tropical trees. Additionally, starch grains of
Colocasia esculenta (taro) and Dioscorea sp. (yam), both common species
in Pacific agriculture, were identified. Furthermore, the presence of
four American taxa Ipomoea batatas (sweet potato), Canna sp. (achira),
Manihot esculenta (manioc), and Xanthosoma sp., was detected. The
occurrence of Canna sp., M. esculenta, and Xanthosoma sp. starch grains
suggests the translocation of previously not described South American
cultivars into the Pacific. The detection of I. batatas from this site
in Rapa Nui constitutes the earliest record of this cultigen in the
Pacific. Our study provides direct evidence for translocation of a set
of traditional Polynesian and South American crop plants at the initial
stages of colonization in Rapa Nui.

The paper even has a reference to Thor Heyerdahl's Kon-Tiki manuscript.

erik simpson wrote:
> https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0298896
>
> Abstract
>
> Starch residue analysis was carried out on stone tools recovered from
> the bottom layer of the Anakena site on Rapa Nui (Easter Island). These
> deposits have been dated to AD 1000–1300 AD and so far, represent the
> earliest evidence of human settlement on this island. Twenty obsidian
> tools were analyzed. Analysis of 46 starch grains recovered from 20
> obsidian tools from the earliest dated level of the Anakena site on Rapa
> Nui provides direct evidence for translocation of traditional crop
> plants at initial stages of the colonization of this island. The
> analysis of starch grains was based mainly on statistical methods for
> species identification but was complemented by visual inspection in some
> cases. Our results identify taxons previously unknown to have been
> cultivated on the island, such as breadfruit (Artocarpus altilis),
> Zingiber officinale (ginger), and starch grains of the Spondias dulcis
> and Inocarpus fagifer tropical trees. Additionally, starch grains of
> Colocasia esculenta (taro) and Dioscorea sp. (yam), both common species
> in Pacific agriculture, were identified. Furthermore, the presence of
> four American taxa Ipomoea batatas (sweet potato), Canna sp. (achira),
> Manihot esculenta (manioc), and Xanthosoma sp., was detected. The
> occurrence of Canna sp., M. esculenta, and Xanthosoma sp. starch grains
> suggests the translocation of previously not described South American
> cultivars into the Pacific. The detection of I. batatas from this site
> in Rapa Nui constitutes the earliest record of this cultigen in the
> Pacific. Our study provides direct evidence for translocation of a set
> of traditional Polynesian and South American crop plants at the initial
> stages of colonization in Rapa Nui.
>
> The paper even has a reference to Thor Heyerdahl's Kon-Tiki manuscript.

"species from South America that could have
been transported along with sweet potato as
part of the crops taken by Polynesians on
return voyages from South America"

There is further discussion of the species
introduction plus this

"Our general results strengthen the evidence of
contacts between Pacific Island peoples and
South American populations. "

Would love to see more on this!