Indigenous Archaeology

Lithic studies

Alaskan archaeology

Beringia

First American

Humanities & Social Sciences, Archaeology

Genome of an early Okhotsk individual reveals ancient admixture between Jomon and Kamchatka lineages
Takehiro Sato; Daisuke Kubo; Yu Hirasawa; Minoru Yoneda; Ryosuke Kimura; Atsushi Tajima; Hirofumi Kato
Scientific Reports, 27 Oct. 2025
English, Scientific journal, Abstract
The prehistoric Okhotsk culture was distributed along the southern coastal regions of the Sea of Okhotsk during the late first millennium AD. A previous study that performed whole-genome sequencing of a late Okhotsk individual suggested two migration waves from the Russian Far East to northern Japan. The first wave is estimated to have originated from the Kamchatka Peninsula around 2000 years before present (BP), and the second from the Amur Basin around 1600 BP. These findings suggest the past existence of an admixed hypothetical population between the Kamchatka and indigenous Jomon lineages in northern Japan between 2000 and 1600 BP, although direct genetic evidence has not yet been obtained. Here, we present the genome data of an early Okhotsk individual (NAT004) excavated from northern Japan. Admixture modelling reveals that the genome can be explained as a mixture of Kamchatka and Jomon ancestries, providing direct support for the existence of the previously hypothesized hypothetical population. This result offers new insights into the prehistoric population dynamics of northern Japan and contributes to the broader understanding of its archaeological and anthropological history.

Integrated analysis of socio-ecological impacts on underground food storage in Beringia
Kazuyuki Saito; Yu Hirasawa; Michael S Koskey; Yoko Kugo; Theresa John; Go Iwahana; Shirow Tatsuzawa
Environmental Research: Ecology, 30 Jun. 2025
Scientific journal

Techno-Morphological Study of Swan Point Burins, from the 14,200-Year-Old Diuktai Phase of the East Beringian Tradition
Yu Hirasawa; Charles E. Holmes
PaleoAmerica, 11, 1, 52, 68, 02 May 2025, [Peer-reviewed]
Scientific journal

Food life history and cold storage in Greater Beringia. Part I: Preliminary interdisciplinary investigation
Saito, K.; Kugo, Y.; Koskey, M.; Iwahana, G.; Hirasawa, Y.; Tatsuzawa, S.; Zhegusov, Y.; Jambaljav, Y.; John, T.A.
Polar Science, 41, Sep. 2024
Scientific journal

Early Beringian Traditions: Functioning and Economy of the Stone Toolkit from Swan Point CZ4b, Alaska
Gauvrit Roux, E.; G{\'o}mez Coutouly, Y.A.; Holmes, C.E.; Hirasawa, Y.
American Antiquity, 89, 2, Apr. 2024
Scientific journal

更新世末から完新世初頭の内陸アラスカにおける環境変化と人類活動の様相
平澤 悠
北太平洋の先住民文化ー歴史・言語・社会, 41, 58, 31 Mar. 2024, [Peer-reviewed], [Lead author]
Japanese, In book

Revisiting Yubetsu Methods in Beringia and Adjacent Regions: An Examination of the Origins of the Early Alaskan Microblade Technologies
Yu Hirasawa
Anthropological Papers of the University of Alaska New Series, 7, 1-2, 63, 85, 2023, [Invited], [Lead author]
English, Symposium

MULTIVOCAL ARCHAEOLOGIES OF THE PACIFIC WAR, 1941–45: Collaboration, Reconciliation, and Renewal
Raffield, B.; Hirasawa, Y.; Price, N.
Multivocal Archaeologies of the Pacific War, 1941?45: Collaboration, Reconciliation, and Renewal, Multivocal Archaeologies of the Pacific War, 1941–45: Collaboration, Reconciliation, and Renewal, 2023
Scientific journal

INTRODUCTION: A War of the Worlds
Ben Raffield; Yu Hirasawa; Neil Price
Multivocal Archaeologies of the Pacific War, 1941–45: Collaboration, Reconciliation, and Renewal, 1, 9, 01 Jan. 2023
In book

Research Trends on Archaeological Studies in Interior Alaska and Yukon Territories
Yu Hirasawa
Senri Ethnological Reports, 156, 171, 203, Nov. 2022, [Lead author]
Japanese, Research institution

Food Life History in Use of Natural Freezing and Snow - Traditional Preservation and Storage from the North to Japan -
Kazuyuki Saito; Go Iwahana; Yoko Kugo; Yu Hirasawa; Shirow Tatsuzawa; Iwao Takei; Yuriy Zhegusov
Summaries of JSSI and JSSE Joint Conference on Snow and Ice Research, 2022, 49, 2022
International conference proceedings

Cultural adaptations and island ecology: Insights into changing patterns of pottery use in the Susuya, Okhotsk and Satsumon phases of the Kafukai sites, Rebun Island, Japan
Ari Junno; Hiroko Ono; Yu Hirasawa; Hirofumi Kato; Peter D. Jordan; Tetsuya Amano; Sven Isaksson
Quaternary International, 623, 19, 34, Elsevier BV, Dec. 2021, [Peer-reviewed]
Scientific journal

Building a high-resolution chronology for northern Hokkaido – A case study of the Late Holocene Hamanaka 2 site on Rebun Island, Hokkaido (Japan)
Ari Junno; Jack P.R. Dury; Christian Leipe; Mayke Wagner; Pavel E. Tarasov; Yu Hirasawa; Peter D. Jordan; Hirofumi Kato
Journal of Archaeological Science: Reports, 36, 102867, 102867, Elsevier BV, Apr. 2021, [Peer-reviewed]
Scientific journal

Walnuts, salmon and sika deer: Exploring the evolution and diversification of Jōmon “culinary” traditions in prehistoric Hokkaidō
Harry K. Robson; Alexandre Lucquin; Kevin Gibbs; Hayley Saul; Tetsuhiro Tomoda; Yu Hirasawa; Toshiro Yamahara; Hirofumi Kato; Sven Isaksson; Oliver E. Craig; Peter D. Jordan
Journal of Anthropological Archaeology, 60, 101225, 101225, Elsevier BV, Dec. 2020, [Peer-reviewed]
Scientific journal

Evaluation of Chiquihuite Cave site, Zacatecas, Mexico, within the peopling of Americas senarios
平澤 悠
Communications of the Palaeo Perspective: 旧石器時代研究への視座, 2, 46, 49, Nov. 2020, [Lead author]
Scientific journal

Evidence of increasing functional differentiation in pottery use among Late Holocene maritime foragers in northern Japan
Ari Junno; Sven Isaksson; Yu Hirasawa; Hirofumi Kato; Peter D. Jordan
Archaeological Research in Asia, 22, 100194, 100194, Jun. 2020, [Peer-reviewed]
English, Scientific journal

A review of early human migration hypotheses in North America: problems on the fluted technology centric view
Yu Hirasawa
日本をめぐる北の文化誌：岡田淳子先生米寿記念論集, 10, 53, 28 Feb. 2020, [Lead author], [Domestic magazines]
Japanese, In book

The relationship between microblade morphology and production technology in Alaska from the perspective of the Swan Point site
Hirasawa, Y.; Holmes, C.E.
Quaternary International, 442, 104, 117, 2017, [Peer-reviewed], [Lead author]
Scientific journal

Diversity of lithic assemblages in interior Alaska and continuity of human populations: recent research trends and problems
Yu Hirasawa
晩氷期の人類社会：北方先史狩猟採集民の適応行動と居住形態, 257, 276, 10 May 2016, [Lead author], [Domestic magazines]
Japanese, In book

Current status and issues of microblade assemblage research in interior Alaska
Yu Hirasawa
古代文化, 67, 3, 110, 117, 110-117, 2015, [Lead author], [Domestic magazines]
Japanese, Scientific journal

Paleolithic Materials Found in Tuva Republic, Russian Federation
Hirofumi, K; Naganuma, M; Suzuki, K; Astakhov, S. N; Makarov, S. S; Hirasawa, Y
Геоарчеология. Этнология. Антропология, 2, 3, 112, 123, 112-123, 2013, [Peer-reviewed], [International Magazine]
English, Scientific journal

Current state of research on the late Pleistocene archaeology in Alaska
Yu Hirasawa, 月刊考古学ジャーナル, 805, 805, 27, 30, Jan. 2025, [Invited], [Lead author]
東京 : ニュー・サイエンス社, Japanese, Introduction commerce magazine

日本旧石器学会 第20回研究発表・シンポジウム 更新世末の西南日本における環境変動と人類活動
平澤 悠, 旧石器研究 = Palaeolithic research / 日本旧石器学会 編, 19, 125, 130, May 2023
日進 : 日本旧石器学会, Japanese

Preliminary report on the excavation of the Phung Quyen rock shelter in northern Vietnam
澤田純明; NGUYEN Thi Mai Huong; NGUYEN Anh Tuan; 江田真毅; 佐藤孝雄; 澤浦亮平; 澤浦亮平; 樋泉岳二; 本郷一美; 平澤悠; 山形眞理子, 日本人類学会大会プログラム・抄録集(Web), 77th, 2023

Food Life History in Use of Natural Freezing and Snow - Traditional Preservation and Storage from the North to Japan -
斉藤和之; 斉藤和之; 岩花剛; 久郷洋子; 平澤悠; 立澤史郎; 竹井巌; ZHEGUSOV Yuriy, 雪氷研究大会講演要旨集(Web), 2022, 2022

Traditional Food Preservation and Cache Using Frozen Environment “Food Life History”: usage and practices of natural freezing
斉藤和之; 斉藤和之; 岩花剛; 久郷洋子; 平澤悠; 立澤史郎, 雪氷研究大会講演要旨集(Web), 2021, 2021

日本のアラスカ考古学研究史と最前線
平澤 悠, 北方から未来へ North to the Future ー日本人が出会ったアラスカー, なし, 46, 50, 2018

本州最北端における最終氷期の陸産貝類群集組成とその後の変遷
黒住耐二; 佐藤孝雄; 奈良貴史; 渡辺丈彦; 澤田純明; 澤浦亮平; 吉永亜紀子; 千葉毅; 金井紋子; 竹内俊吾; 平澤悠, 日本貝類学会大会研究発表要旨集, 2014, 2014

MULTIVOCAL ARCHAEOLOGIES OF THE PACIFIC WAR, 1941–45: Collaboration, Reconciliation, and Renewal
Ben Raffield; Yu Hirasawa; Neil Price
01 Jan. 2023, 9781000912760, Others

氷室・風穴（自然冷熱エネルギー）の機能を地域環境保全へ還元する再エネ利用研究
科学研究費助成事業
01 Apr. 2024 - 31 Mar. 2027
斉藤 和之; 立澤 史郎; 平澤 悠; 澤田 結基; 木村 賢人; 岩花 剛
日本学術振興会, 基盤研究(B), 国立研究開発法人海洋研究開発機構, 24K03143

Lithic raw material utilization of the first migrants in middle Tanana River area, Alaska
Grants-in-Aid for Scientific Research
01 Apr. 2017 - 31 Mar. 2020
Hirasawa Yu
This study aimed to reveal 1) the distribution patterns of lithic raw material used for microblade industry, 2) historical change of microblade and burin technology, and 3) the relationship between production technology and lithic raw materials in interior Alaska. To study these subtopics, I conducted lithic raw material distribution survey near site concentrated area and examined microblade cores and burins in terms of their technology and raw materials from Swan Point and Broken Mammoth multi-component sites. Consequently, chert distributing area was newly found near the sites, and microblade and burin technology and raw materials are more different at Swan Point oldest component from the other later assemblages.
Japan Society for the Promotion of Science, Grant-in-Aid for Young Scientists (B), 17K17560