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The cells have a memory!


The power of numbers
Leonard Hayflick Scientist
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I did the mathematics in respect to this argument and proposed that if the molecule is hydrogen, the smallest molecule... if the initial cells in the population – that is, the primary culture – consisted entirely of oxygen... of hydrogen, then what is the likelihood that  a hydrogen molecule would end up in the... after 50 population doublings? And the answer is: after knowing the weight of a single cell – and you can determine that if you know the weight of a million cells, which is easy to do; you simply do the math and you know the weight of a single cell – and by doing those mathematics, you come to the conclusion that in order for a cell of the fiftieth population doubling to have in it a single hydrogen molecule from the start of lineage, that would be impossible. The molecule would have been diluted out far earlier than 50 population doublings.

It's important to understand that 50 population doublings, using the number 50 sounds trivial, but if you do the mathematics, you're talking about two to the fiftieth power. Two to the fiftieth power is roughly 10 to the fifteenth power. And if you do more mathematics, you learn that two to the fiftieth power is equivalent to 20 million metric tonnes of cells. That is a big number. And, if you want some context in which to appreciate that number, you may recall and old children's fairy tale involving a king who offered a prize if one of his subjects did some major favour for him, which did indeed happen.

The subject said to the king, 'I want in return for this favour, a grain of wheat put on a checker board; one grain on the first board section and then double it for 64 blocks.' Well, of course, well before the 64th block, you reach a number of wheat grains, more than have ever been produced on this planet. So that gives you some idea of the powers of numbers. That... that became a critical point later as I'll mention. That is the point that it could not be that a molecule bigger than hydrogen would survive after the fiftieth population doubling.

Leonard Hayflick (b. 1928), the recipient of several research prizes and awards, including the 1991 Sandoz Prize for Gerontological Research, is known for his research in cell biology, virus vaccine development, and mycoplasmology. He also has studied the ageing process for more than thirty years. Hayflick is known for discovering that human cells divide for a limited number of times in vitro (refuting the contention by Alexis Carrel that normal body cells are immortal), which is known as the Hayflick limit, as well as developing the first normal human diploid cell strains for studies on human ageing and for research use throughout the world. He also made the first oral polio vaccine produced in a continuously propogated cell strain - work which contributed to significant virus vaccine development.

Listeners: Christopher Sykes

Christopher Sykes is a London-based television producer and director who has made a number of documentary films for BBC TV, Channel 4 and PBS.

Tags: hydrogen, molecule, primary culture, population doubling, weight, dilution

Duration: 3 minutes, 12 seconds

Date story recorded: July 2011

Date story went live: 08 August 2012