Island Colonization and Environmental Sustainability in the Postglacial Mediterranean

Abstract

Island environments present challenges to human colonization, but we have a poor understanding of how environmental difference drives heterogeneous patterns of insular settlement. In this paper, we assess which environmental and geographic variables positively or negatively affect the long-term sustainability of human settlement on islands. Using the postglacial Mediterranean basin as a case study, we assess the impact of area, isolation index, species richness, and net primary productivity (NPP) on patterns of island occupation for both hunter-gatherer and agropastoral populations. We find that models involving area most effectively accounts for sustainability in hunter-gatherer island settlement. The agropastoral data are noisier, perhaps due to culturally specific factors responsible for the distribution of the data; nonetheless, we show that area and NPP exert profound influence over sustainability of agropastoral island settlement. We conclude by suggesting that this relates to the capacity of these variables to impact demographic robusticity directly.

Global Patterns in Island Colonization during the Holocene

“…Our broader exploration further bears out the importance of these factors cross-culturally. This is especially the case in the Caribbean and Mediterranean (see now Plekhov et al, 2021), where a handful of very large islands (the Greater Antilles and the Mediterranean 'big five'), or smaller islands with very low isolation indices (Trinidad; the Dalmatian islands), witness much earlier colonization than smaller, remoter islands. Distance, area, and configurational effects also seem relevant in the Gulf of Guinea, and the Ryukyus, Kurils and Aleutians, but less so in the open-ocean contexts of Remote Oceania, the Indian Ocean and the North Atlantic, as discussed further below.…”

“…There is richer and better-understood evidence for Early Holocene HGF island activity, which is cumulatively indicative of growing maritime exploration and knowledge networks, and sometimes clearly involved experiments in longer-term island living through the exploitation of local insular (including obsidian) and marine resources. Much of this is concentrated on the largest islands (Mesolithic on Sardinia, Corsica, Sicily and Crete, plus a slightly earlier local Epipalaeolithic at the Pleistocene-Holocene transition on Cyprus), as well as a handful of smaller islands, the latter perhaps more indicative of seasonal exploitation (Broodbank, 2006;Cherry & Leppard, 2018a;Plekhov et al, 2021). Yet the striking lack of secure transitional stratigraphic sequences between such late HGF and subsequent Neolithic agropastoral contexts suggests that HGF communities, while interesting in their own right and assuredly contributory to the dissemination of maritime and insular knowledge to later island settlers, had little impact on the ancestry or structure of subsequent colonization processes involving farmers (as we shall see, arguably unlike the situation in ISEA and the Caribbean).…”

“…Their millennia-long, widespread Early Holocene reluctance to do so for purposes of settlement provides suggestive evidence concerning the factors driving and constraining island colonization. The initial preference for big islands, or islands extremely proximate to continental coast, has long been noted, and interpreted explicitly in biogeographic terms (Cherry, 1981(Cherry, , 1984, and a biogeographic model remains a powerful predictor of early versus late colonization (Plekhov et al, 2021). However, recognizing the palpable ability to traverse substantial sea-gaps, this preference may relate less to raw island geometry, and more to the fact that the 'big five' islands possess many of the features that attracted early agropastoral interest in continental environmental niches too, such as abundant workable soils and relatively reliable orographically-derived hydrologies.…”

“…Accordingly, the outline of Mediterranean island colonization may be seen less as a function of constraining distance (in a context where crossings tended to be modest, rarely more than 25-50 km or one to two days even in paddled canoes), and more as emergent from demographic and other drivers working in tandem. In other words, small islands tended to be unattractive prospects for effectively obligate Mediterranean agropastoral populations, unless something radical happened to alter the calculus of moving versus staying (Plekhov et al, 2021;cf. Cherry & Leppard, 2018a)-a theme that will prove recurrent.…”

Triumph of the Commons: Sustainable Community Practices on Rapa Nui (Easter Island)

“…In archaeology, researchers who have attempted to identify or measure past sustainability focus largely on the first component-continuation, i.e., the longevity or persistence of some phenomenon in the archaeological record (e.g., [4,7,11,12,[70][71][72][73][74][75][76][77][78][79][80][81][82][83][84][85]). While this component does not capture all aspects of "sustainability" central to the contemporary world, the aggregate and diachronic nature of the archaeological record is well suited for tracking differential levels of persistence and building hypotheses as to why these past traditions succeeded and/or failed.…”