01 December 2014
ByAppeared in BioNews 782
Complex organisms, according to Darwinian doctrine, randomly evolved from simple lifeforms through the process of natural selection. In other words, you and I - and all the diverse lifeforms on our planet - are the result of millions of years of totally blind trial-and-error.
But precisely how adaptation and innovation fits into the process of natural selection remains a mystery. Professor Andreas Wagner, an evolutionary biologist at the University of Zurich, thinks he's cracked the puzzle and tried to get us to agree at this Royal Institution lecture.
He opened with a quote from the pioneering early geneticist Hugo De Vries: 'Natural selection may explain the survival of the fittest, but it cannot explain the arrival of the fittest.' In other words, Darwin's theory of natural selection provides a plausible explanation for the selective preservation of beneficial traits. It does not, however, explain how these new traits arise.
He postulates that nature's ability to innovate - to create the new; its 'innovability' - is governed by an organisational process and not only by random change.
To explain this, Professor Wagner used the analogy of a large network of synonymous texts distributed randomly across a 'universal library'. This library, akin to the 'Library of Babel' described by Jorge Luis Borges, contains texts covering all possible topics in the universe - including those not yet conceived.
Professor Wagner likened these texts to the amino acid sequences that encode genes. Nature's random exploration in this universal library uncovers different amino acid sequences that encode genes with similar phenotypical expressions.
Through this process, nature 'discovers what was already there all the time'. It preserves traits essential for survival, and constantly explores new ways of improving those traits, leading to the 'arrival of the fittest'.
Professor Wagner's lecture provided fascinating insight into nature's creative abilities. The lecture drew a parallel between nature's innovability and our present day technological advancements. If we could harness nature's innovative potential we could, for example, produce cars able to run on petrol, diesel, orange juice or fizzy drinks, all at the same time.
Professor Wagner advanced an engaging, provocative but logical argument backed by years of research and data from computational simulations that could, at least in part, help us begin to understand the origins of complex life.