MSGID: 1:317/3 645b1de4   
   PID: hpt/lnx 1.9.0-cur 2019-01-08   
   TID: hpt/lnx 1.9.0-cur 2019-01-08   
    Evidence of Ice Age human migrations from China to the Americas and   
   Japan    
      
     Date:   
         May 9, 2023   
     Source:   
         Cell Press   
     Summary:   
         Scientists have used mitochondrial DNA to trace a female lineage   
         from northern coastal China to the Americas. By integrating   
         contemporary and ancient mitochondrial DNA, the team found evidence   
         of at least two migrations: one during the last ice age, and one   
         during the subsequent melting period. Around the same time as the   
         second migration, another branch of the same lineage migrated to   
         Japan, which could explain Paleolithic archeological similarities   
         between the Americas, China, and Japan.   
      
      
         Facebook Twitter Pinterest LinkedIN Email   
      
   ==========================================================================   
   FULL STORY   
   ==========================================================================   
   Scientists have used mitochondrial DNA to trace a female lineage from   
   northern coastal China to the Americas. By integrating contemporary   
   and ancient mitochondrial DNA, the team found evidence of at least two   
   migrations: one during the last ice age, and one during the subsequent   
   melting period. Around the same time as the second migration, another   
   branch of the same lineage migrated to Japan, which could explain   
   Paleolithic archeological similarities between the Americas, China,   
   and Japan. The study appears May 9 in the journal Cell Reports.   
      
   "The Asian ancestry of Native Americans is more complicated than   
   previously indicated," says first author Yu-Chun Li, a molecular   
   anthropologist at the Chinese Academy of Sciences. "In addition to   
   previously described ancestral sources in Siberia, Australo-Melanesia,   
   and Southeast Asia, we show that northern coastal China also contributed   
   to the gene pool of Native Americans."  Though it was long assumed that   
   Native Americans descended from Siberians who crossed over the Bering   
   Strait's ephemeral land bridge, more recent genetic, geological, and   
   archeological evidence suggests that multiple waves of humans journeyed   
   to the Americas from various parts of Eurasia.   
      
   To shed light on the history of Native Americans in Asia, a team of   
   researchers from the Chinese Academy of Sciences followed the trail of an   
   ancestral lineage that might link East Asian Paleolithic-age populations   
   to founding populations in Chile, Peru, Bolivia, Brazil, Ecuador, Mexico,   
   and California. The lineage in question is present in mitochondrial DNA,   
   which can be used to trace kinship through the female line.   
      
   The researchers scoured over 100,000 contemporary and 15,000 ancient   
   DNA samples from across Eurasia to eventually identify 216 contemporary   
   and 39 ancient individuals belonging to the rare lineage. By comparing   
   the accumulated mutations, geographic locations, and carbon-dated age   
   of each of these individuals, the researchers were able to trace the   
   lineage's branching path.   
      
   They identified two migration events from northern coastal China to the   
   Americas, and in both cases, they think that the travelers probably set   
   dock in America via the Pacific coast rather than by crossing the inland   
   ice-free corridor (which would not have opened at the time).   
      
   The first radiation event occurred between 19,500 and 26,000 years ago   
   during the Last Glacial Maximum, when ice sheet coverage was at its   
   greatest and conditions in northern China were likely inhospitable for   
   humans. The second radiation occurred during the subsequent deglaciation   
   or melting period, between 19,000 and 11,500 years ago. There was a rapid   
   increase in human populations at this time, probably due to the improved   
   climate, which may have fueled expansion into other geographical regions.   
      
   The researchers also uncovered an unexpected genetic link between Native   
   Americans and Japanese people. During the deglaciation period, another   
   group branched out from northern coastal China and traveled to Japan. "We   
   were surprised to find that this ancestral source also contributed to   
   the Japanese gene pool, especially the indigenous Ainus," says Li.   
      
   This discovery helps to explain archeological similarities between the   
   Paleolithic peoples of China, Japan, and the Americas. Specifically, the   
   three regions share similarities in how they crafted stemmed projectile   
   points for arrowheads and spears. "This suggests that the Pleistocene   
   connection among the Americas, China, and Japan was not confined to   
   culture but also to genetics," says senior author Qing-Peng Kong, an   
   evolutionary geneticist at the Chinese Academy of Sciences.   
      
   Though the study focused on mitochondrial DNA, complementary evidence from   
   Y chromosomal DNA suggests that male ancestors of Native Americans also   
   lived in northern China at around the same time as these female ancestors.   
      
   This study adds another piece to the puzzle that is Native American   
   ancestry, but many other elements remain unclear. "The origins of several   
   founder groups are still elusive or controversial," says Kong. "Next,   
   we plan to collect and investigate more Eurasian lineages to obtain a   
   more complete picture on the origin of Native Americans."   
       * RELATED_TOPICS   
             o Fossils_&_Ruins   
                   # Archaeology # Ancient_Civilizations # Ancient_DNA   
                   # Human_Evolution # Early_Humans # Origin_of_Life #   
                   Cultures # Evolution   
       * RELATED_TERMS   
             o Human_migration o Indigenous_peoples_of_the_Americas o   
             Chichen_Itza o RNA o Maya_civilization o Little_Ice_Age o   
             Geologic_temperature_record o The_Genographic_Project   
      
   ==========================================================================   
   Story Source: Materials provided by Cell_Press. Note: Content may be   
   edited for style and length.   
      
      
   ==========================================================================   
   Journal Reference:   
      1. Li and Gao et al. Mitogenome evidence shows two radiation events and   
         dispersals of matrilineal ancestry from northern coastal   
         China to the Americas and Japan. Cell Reports, 2023 DOI:   
         10.1016/j.celrep.2023.112413   
   ==========================================================================   
      
   Link to news story:   
   https://www.sciencedaily.com/releases/2023/05/230509122008.htm   
      
   --- up 1 year, 10 weeks, 1 day, 10 hours, 50 minutes   
    * Origin: -=> Castle Rock BBS <=- Now Husky HPT Powered! (1:317/3)   
   SEEN-BY: 15/0 106/201 114/705 123/120 153/7715 218/700 226/30 227/114   
   SEEN-BY: 229/110 112 113 307 317 400 426 428 470 664 700 292/854 298/25   
   SEEN-BY: 305/3 317/3 320/219 396/45   
   PATH: 317/3 229/426