Sunday, April 13, 2008

Programmed life

Author: Khalil A. Cassimally

Does aging happen by chance? Is aging the breaking down of an organism till the latter eventually stops working?

According to Valter Longo's latest research, which was published in the September 27 edition of the Journal of Cell Biology, aging is a programmed process. For Longo's part, aging is supposed to ensure the premature death of the majority of a population.

The dead will then consequently provide nutrients for the sake of a few individuals who have acquired genetic mutations. (Think of yeast rather than big complex mammals.) These mutants are more adapted to their environment than the other 'normal' organisms. Therefore these 'sacrificial' deaths increase the chances of reproduction of the mutants as the latter will have more nutrients to feed on.

Now Charles Darwin may not be very happy with Longo's theory. Darwin's natural selection happens at individual level. The better suited to its environment an organism is, the more probable that it will reproduce. This ensures that the species changes or evolves over time as such type of reproduction brings genetic changes to the offsprings. This makes the offsprings more adapted to their ever-changing environment.

Longo's theory however rests on the group selection theory. Many scientists think that this theory is incorrect. The latter proposes that selection happens not at individual level but at group level instead.

Longo's research is mainly based on the observation of programmed aging in yeast. Scientists have used yeasts because the molecular pathway that regulates its longevity is similar to other more complex organisms like mice and possibly humans.

The results of this research are surprising. Yeasts, which were studied died well before they were supposed to in order to provide nutrients for those yeasts within that same population which have acquired genetic mutations. In short, many millions of yeasts died early to suit the few better-adapted mutant yeasts. Can this process happen in humans as well?

"If aging is programmed in yeast and the latter's molecular pathway is very similar to human's, then isn't it possible that humans also die earlier than they have to?" said Valter Longo.

Apart from the possibility that we might have been wrong in sticking with Darwin's all-too-known theory for so long-provided Longo's theory is proven to be correct- gerontologists (scientists studying the aging process) are now conjecturing that aging may actually be healed.

It seems easier to tweak the programming in a computer than to try to replace part after part in an old car that is steadily collapsing.

For Valter Longo, most organisms undergo programmed longevity. Is life therefore supposed to be programmed?

About the author: Khalil A.Cassimally is the editor in chief of Astronomy Journal and Astronomy Journal Ezine. He is also the co-founder of the RCPL Astronomy Club. He is currently Senior Columnist at BackWash.com and Columnist for bbc.co.uk h2g2 The Post where he writes 'Not Scientific Science' column.

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