50 years after - examination of some circumstances around the establishment of the correct chromosome number of man
Bibliographic record
Abstract
Three authors, Levan (1975, 1978), Tjio (1978) and Hultén (2002) have independently described the establishment of the correct chromosome number of man (Tjio and Levan 1956) and the background to that study. However, the three authors provide strikingly different accounts of this historical discovery. In this study I have examined the consistency between these accounts and details provided by the logbook kept at Cancer Chromosome Laboratory, University of Lund. For complementary details I have also consulted several persons that were active at the Institute of Genetics, Univ. of Lund, at the time of the discovery. Levan's (1975)Levan's (1978) accounts are both written in a modest way compared to the more self-centered narratives of Tjio and Hultén. His accounts are also consistent with all details that can be collected from the logbook. However, and most unfortunately, Levan is not explicit with respect to the dates of what might be different cytogenetic observations related to the determination of the correct chromosome number of man. The logbook leaves no room for various temporal details given by Tjio, which, if correct, might substantiate his account. Also Tjio's introduction of an alter ego into the narrative is apt to lessen the general credibility of his account. Tjio's (1978) contention of having made his human chromosome preparations at 2 a.m. on December 22nd or 23rd would be consistent with his claim that he arrived from Spain in early December 1955. His account of this crucial issue is incorrect, however, as he did not arrive at the Cancer Chromosome Laboratory until December 19. Hultén's claim of involvement becomes highly questionable in the light of her fading recollections of both the localities at the Institute of Genetics and the persons working there. Her temporal account, like that of Tjio, remains unsupported by the logbook. Examination of the logbook for temporal details relating to the establishment of the correct chromosome number of man suggests that Levan made his first preliminary 2n=46 human chromosome counts around December 20th-23rd, 1955, and that Tjio made his first conclusive preparations two-three weeks after his arrival from Spain, that is in early January 1956.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.003 | 0.009 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.002 | 0.002 |
| Science and technology studies | 0.008 | 0.013 |
| Scholarly communication | 0.005 | 0.005 |
| Open science | 0.001 | 0.003 |
| Research integrity | 0.002 | 0.005 |
| Insufficient payload (model declined to judge) | 0.007 | 0.001 |
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; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
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".