Biogeography and adaptation in the Kuril Islands, Northeast Asia

The island biogeography of human population size

For decades, biogeographers have sought a better understanding of how organisms are distributed among islands. However, the island biogeography of humans remains largely unknown. Here, we investigate how human population size varies among 486 islands at two spatial scales. At a global scale, we tested whether population size increases with island area and declines with island elevation and nearest mainland, as is common in non-human species, or whether humans escape such biogeographic constraints. At a regional scale, we tested whether population sizes vary among islands within archipelagos according to the positioning of different cultural source pools. Results illustrate that on a global scale, human populations increased in size with island area, similar to non-human species, yet they did not decline in size with elevation and distance to nearest mainland. At a regional scale, human population size often varied among islands within archipelagos relative to the location of different cultural source pools. Despite broad-scale similarities in the geographical distribution of human and non-human species among islands, results from this study indicate that the island biogeography of humans may also be influenced by archipelago-specific social, political and historical circumstances.

Increased information on biodiversity from the neglected part of the North Pacific contributes to the understanding of phylogeny and taxonomy of nudibranch molluscs

Understanding of the biological diversity, involving molecular phylogenetic methods, is a fundamental task for a broad array of evolutionary, taxonomic, and ecological studies, as well as a basis for conservation. Our hydrobiological survey during an expedition in 2021 to the coastal waters of the Kuril Islands (the northwestern Pacific) revealed the undocumented diversity of the nudibranch molluscs. Two new species of the genera Zelentia and Cuthonella are described here using analysis of fine-scale morphological and molecular data. Representatives of the genus Zelentia prior to this study were known only from the North Atlantic and from the Canadian and US northeastern Pacific. In addition, two new distributional records of the previously described species Cuthonella denbei Korshunova et al., 2020 and Cuthonella soboli Martynov, 1992 are presented here for the first time. The molecular phylogenetic framework for the majority of the species of the genera Cuthonella and Zelentia, including the two new species, confirmed the taxonomic distinctness of the genus Zelentia (family Trinchesiidae) and the genus Cuthonella (family Cuthonellidae), and represents another important result of this study.

Human Paleodemography and Paleoecology of the North Pacific Rim from the Mid to Late Holocene

Using 14 proxy human population time series from around the North Pacific (Alaska, Hokkaido and the Kuril Islands), we evaluate the possibility that the North Pacific climate and marine ecosystem includes a millennial-scale regime shift cycle affecting subsistence and migration. We develop both visual and statistical methods for addressing questions about relative population growth and movement in the past. We introduce and explore the use of a Time Iterative Moran I (TIMI) spatial autocorrelation method to compare time series trends quantitatively - a method that could prove useful in other paleoecological analyses. Results reveal considerable population dynamism around the North Pacific in the last 5000 years and strengthen a previously reported inverse correlation between Northeast and Northwest Pacific proxy population indices. Visual and TIMI analyses suggest multiple, overlapping explanations for the variability, including the potential that oscillating ecological regime shifts affect the North Pacific basin. These results provide an opening for coordinated research to unpack the interrelated social, cultural and environmental dynamics around the subarctic and arctic North Pacific at different spatial and temporal scales by international teams of archaeologists, historians, paleoecologists, paleoceanographers, paleoclimatologists, modelers and data management specialists.

Island Colonization and Environmental Sustainability in the Postglacial Mediterranean

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.