Bibliographic record
Abstract
To evaluate the number and time of the migration(s) that colonized the New World we analyzed all available sequences of the first hypervariable segment of the human mitochondrial DNA control region, including 544 Native Americans. Sequence and population trees showed that the Amerind, Na-Dene, and Eskimo are significantly closer among themselves than anyone is to Asian populations, with the exception of the Siberian Chukchi, that in some analyses are closer to Na-Dene and Eskimo. Nucleotide diversity analyses based on haplogroup A sequences suggest that Native Americans and Chukchi originated from a single migration to Beringia, probably from east Central Asia, that occurred approximately 30,000 or approximately 43,000 years ago, depending on which substitution rate is used, with 95% confidence intervals between approximately 22,000 and approximately 55,000 years ago. These results support a model for the peopling of the Americas in which Beringia played a central role, where the population that originated the Native Americans settled and expanded. Some time after the colonization of Beringia they crossed the Alberta ice-free corridor and peopled the rest of the American continent. The collapse of this ice-free corridor during a few thousand years 14,000-20,000 years ago isolated the people south of the ice-sheets, who gave rise to the Amerind, from those still in Beringia; the latter originated the Na-Dene, Eskimo, and probably the Siberian Chukchi.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.001 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.003 | 0.017 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; both teacher heads agree on what is shown here.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".