Dude, you can't count...

Jan 05 2012 Published by under Uncategorized

From time to time, scientists end up bucking the commonly established and deeply entrenched beliefs of the scientific community, sometimes to their own peril.  And a fair amount of the time, they may just end up being wrong, but in some instances, it really is that they got it right and the rest of us dopes were just wrong.  Reaching back into the annuls of time we can find a textbook example of this when you study the history of the human chromosome number.  Of course all our textbooks tell us that the diploid number in man, woman, and child is 46 chromosomes.  However this was not always the agreed upon number.

The original agreed upon number was 48 chromosomes set forth by eminent zoologist Theophilus Painter, when he observed 24 meiotic chromosomes on a metaphase spread of spermatocytes way back in 1923.  This number would remain in hearts and minds of budding cytologists for 33 years.  Until another cytologist, T. C. Hsu, the "father of mammalian cytogenetics" improved the metaphase spread method by incorporating hypotonic buffers and cell fixation techniques.  Further refining the process were Joe Hin Tjio and Albert Levan, who used colchicine to arrest the cell in metaphase increasing the number of spreads for analysis.  Upon analyzing over 20 different fetal lung cell cultures, they came to a consensus that the chromosome number was 46, not the long believed 48.

The kicker to all of this was that for years other scientists were making metaphase spreads from cells of different tissues and coming up with 46 chromosomes, but sat on the data or refused to believe it was true because it deviated from Painter's gospel of 48.  Later other scientists including Hsu would revise their number but others held steadfast until the final consensus came in the late 50s.

4 responses so far

  • tideliar says:

    i remember learning that and being all like, WTF dude?! Amazing how we toe the line isn't it!

  • Pascale says:

    "The kicker to all of this was that for years other scientists were making metaphase spreads from cells of different tissues and coming up with 46 chromosomes, but sat on the data or refused to believe it was true because it deviated from Painter's gospel of 48. "
    Or they could not get their data published because the reviewers knew that they must have done something wrong!

  • Jim Thomerson says:

    Thanks for the story. I got into it after 46 was firmly accepted and was aware, without detail, that 48 had been accepted at one time. I think if I had been getting 46, my first reaction would be to think I had a unique and interesting situation. I probably would have published on it as a novelty. "Unique karyotype of an inbred lineage from --------.", then ""Occurrence of unique karyotype in distantly related lineages from -------."

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