46 or
48?
How did scientists arrive
to the human chromosome
count of 46? What if I told you
they were initially wrong? Travel
back in time to know the real story.
Read on!
L
et’s take a trip back in time to the year 1955 and ask a random univer-
sity biology student, the human chromosome count. The answer would
be an undoubted 48. Yes, it’s not a typo out there! For three long decades,
the chromosome number in humans was regarded to be 48. Now let’s say, you
are not prepared to agree and the university student you’ve just met, too just isn’t
willing to budge. He rather invites you to take a look into a karyotype preparation
under the microscope and decide for yourself. Now we’d have two eccentrics fight
over the same cytological preparation with two different values for the same chro-
mosome number. All because they were counting with a number already in the back
of their mind to which they had to reach to.
18
Renowned scientists of that time had established 2n = 48, and this was universally
accepted. If you were a student back then and could see only 46, would you challenge
the establishment, blame the preparation or play safe by reporting it as an obvious 48? I
am reminded of a pathology practical class where one slide had been erroneously labeled.
It was fun to watch people trying to fit in the expected observations into the wrong slide.