Patterns such as day and night or seasons, were very important for the emergence of the first life on Earth. This is stated by chemist Peer van Duppen in his research on which he will receive his PhD at Radboud University on 17 December.
How humans developed from the first cell can be explained by Darwin’s theory of evolution. But how life itself originated is unclear. Van Duppen: ’The prevailing idea is that reactions arose in some kind of primordial soup, without DNA or enzymes. In the chemical reactions we know, in our environment or in ourselves, DNA and enzymes are crucial: DNA is a kind of instruction book that states exactly which substance should be converted into another substance, and the enzymes are the machines that do the work. So how can it happen that reactions were turned on or off without DNA or enzymes?’
Formose reaction
For his research, the chemist used a chemical reaction - the formose reaction - which is believed to have been important in the emergence of early life. In this reaction, complex sugars are formed from simple molecules. This creates a kind of web of reactions that keeps expanding. Van Duppen: ’The primordial soup is totally chaotic and has no direction. But in a formose reaction, the environment can direct which part of the network is used and which molecules are formed.’
Van Duppen put a substance (formaldehyde, which was also present in the atmosphere of primitive earth) into a mini reactor the size of a fingertip. To this he added a sugar molecule. He found that adding certain patterns from the environment ensured that certain reactions could be properly controlled. Van Duppen: ’Patterns such as day and night, or changing seasons, caused some substances to be produced more than others. Those patterns therefore influenced the reactions that took place. Without those patterns, chaos endured.’
The chemist thinks this was also the case on primitive earth. ’There were certain substances present, like formaldehyde and simple sugars, which swirled around like a soup, totally chaotic. But by adding a pattern like a season, it became more ordened. We think those patterns were therefore very important for the emergence of early life.’
