High in the Indian Himalayas, situated at an elevation exceeding 5,000 meters, Roopkund Lake has served for decades as the center of an enduring archaeological puzzle. Scattered across the glacial shores of the remote basin are the skeletal remains of several hundred individuals.

For generations, local folklore and preliminary anthropological assessments posited that the dead were victims of a singular catastrophic event, such as an unprecedented hailstorm that decimated a medieval pilgrimage or a lost military expedition. However, comprehensive genomic testing conducted in 2019 fundamentally dismantled this monolithic narrative, revealing a far more complex history of human movement across the high-altitude terrain.

​The paradigm-shifting findings, published in the journal Nature Communications, emerged from a collaborative biomolecular analysis involving institutions such as the Max Planck Institute for the Science of Human History, Harvard University, the Centre for Cellular and Molecular Biology, and the Birbal Sahni Institute of Palaeosciences. Researchers extracted and sequenced whole-genome ancient DNA from 38 skeletal specimens retrieved from the lake.

The resulting data established that the remains do not belong to a single homogeneous population. Instead, the genetic sequences map to at least three highly distinct geographical ancestries, proving that the accumulation of human remains at the site occurred over multiple, temporally isolated episodes.

​The most populous genetic cluster identified in the study consists of 23 individuals whose genetic signatures fall within the broad variation of present-day South Asians. Rather than representing a single endogamous community or a localized highland population, this group exhibited diverse lineages. The genomic data suggests they originated from various distinct geographic and socioeconomic backgrounds across the Indian subcontinent.

Radiocarbon dating of these specific remains placed their time of death at approximately 800 CE. Chronological analysis indicated that even within this South Asian cohort, the depositions likely occurred in multiple distinct events during the medieval period.

​The second major genetic cluster yielded an unexpected geographical origin, significantly expanding the scope of the site’s historical footprint. Genome analysis of 14 individuals revealed ancestry closely aligning with present-day populations in the eastern Mediterranean, with specific genetic affinities to inhabitants of mainland Greece and the island of Crete. Radiocarbon dating for this Mediterranean-linked group established their presence at the lake around 1800 CE.

The temporal gap of nearly a millennium between the South Asian and Mediterranean depositions categorically invalidated the prevailing hypothesis of a single mass-casualty event at the glacial lake.

​A final, singular specimen further complicated the demographic profile of the site. One individual sequenced in the study demonstrated genetic markers characteristic of Southeast Asian populations, also dating to the 19th century. The exact motivations driving eastern Mediterranean migrants to the remote reaches of the Nanda Devi biosphere remain undetermined in the historical record. Nonetheless, their presence at an inhospitable altitude underscores the extent of global movement and maritime connectivity during the early modern period.

​To corroborate the genomic data, the research team conducted stable isotope dietary reconstructions on the bone collagen of the specimens. The isotopic signatures provided secondary confirmation of the distinct population groupings. The individuals with South Asian ancestry displayed highly variable dietary patterns, marked by a reliance on both C3 and C4 plant sources. This dietary variance aligns with the genetic evidence, pointing to a mix of millet, wheat, and rice staples indicative of an agriculturally diverse society with multiple socioeconomic strata.

​Conversely, the stable isotope analysis of the 14 individuals with eastern Mediterranean ancestry revealed a starkly different dietary history. Their bone chemistry exhibited isotopic ratios consistent with diets heavily reliant on distinct terrestrial and marine food webs typical of the Mediterranean basin. The isotopic data lacked any transitional indicators that would suggest prolonged acclimatization to South Asian food sources. This finding implies that the Mediterranean group undertook a relatively rapid journey to the Himalayas and perished shortly after their arrival in the region, before their skeletal isotopes could adapt to local dietary inputs.

​The physical environment of Roopkund Lake presented unique challenges for researchers attempting to reconstruct its history through conventional archaeological methods. The site is a dynamic glacial landscape, subjected to frequent rockslides, extreme weather cycles, and the seasonal freezing and thawing of the lake bed. Over the past century, the remains have been routinely disturbed by trekkers, local pilgrims, and early expeditions who manipulated the bones and removed associated artifacts. This extensive taphonomic disturbance rendered traditional stratigraphic dating nearly impossible, making biomolecular analysis the only viable mechanism for deciphering the chronology of the site.

​The successful extraction of viable ancient DNA from the Roopkund remains represents a significant methodological milestone for bioarchaeology in South Asia. DNA preservation is notoriously poor in the region due to extreme climatic fluctuations; however, the persistent sub-zero temperatures at the high-altitude lake acted as a natural cryogenic vault. By utilizing advanced next-generation sequencing libraries targeting approximately 1.2 million single nucleotide polymorphisms, geneticists were able to bypass the environmental degradation that typically compromises osteological material in lower altitudes.

​The implications of the 2019 study extend beyond the immediate geographic confines of the Himalayan lake. The research established a new baseline for investigating highly disturbed archaeological sites where spatial context has been lost. It demonstrated that integrating radiocarbon dating, stable isotope analysis, and whole-genome sequencing can effectively reverse-engineer the demographic parameters of a site. The multidimensional approach transformed an anomalous mass grave into a longitudinal ledger of human migration, revealing a complex intersection of regional travelers traversing the same hazardous mountain pass a thousand years apart.

Kami Rita, 56, reached the 8,849-meter (29,032-foot) summit at 10:12 a.m. local time while guiding climbers according to Nepal’s Department of Tourism.
The department described the achievement as a “historic milestone” and praised the Sherpa guide for his contribution to Nepal’s mountain tourism industry.

Authorities also said Sherpa climber Lakhpa Sherpa, 52, completed her 11th ascent of Everest, the highest number recorded by a woman. Further details about the expedition were not immediately available.

Kami Rita, who was born in Thame village in Nepal’s Solukhumbu district, first climbed Everest in 1994 and has summited nearly every year since, except during seasons when expeditions were canceled in 2014, 2015 and 2020 due to avalanches, earthquakes and the COVID-19 pandemic. In several years, he reached the summit more than once in a single climbing season.

Thame is also the birthplace of legendary Sherpa climber Tenzing Norgay, who, alongside New Zealand mountaineer Edmund Hillary, became the first confirmed climbers to reach Everest’s summit in 1953.

More than 8,000 people have climbed Everest since the first successful ascent more than seven decades ago, many completing multiple expeditions.
Among non-Sherpa climbers, British mountaineer Kenton Cool holds the record with 19 Everest summits, followed by American climbers Dave Hahn and Garrett Madison with 15 ascents each. Cool and Madison are currently participating in expeditions on Everest this season.

Sherpa guides play a central role in Nepal’s mountaineering industry, assisting foreign climbers on Everest and other Himalayan peaks, with climbing tourism remaining a key source of income for many families in the Solukhumbu region.

Nepal has issued 492 climbing permits for Everest during the current March-to-May season, according to tourism authorities. Three Nepali climbers have died on the mountain this month.