How is bateria evolving to "eat" plastic?
The bacteria cling to the plastic breaking it down into terephthalic acid and ethylene glycol. They then digest those two substances. - this is what I already understand.
However, how could bacteria evolve to degrade plastic if this was created in this century?
The bacteria cling to the plastic breaking it down into terephthalic acid and ethylene glycol. They then digest those two substances. - this is what I already understand.
However, how could bacteria evolve to degrade plastic if this was created in this century?
1 Answer
The bacteria have most likely not evolved in the Neo Darwinian sense.
Explanation:
The bacteria have evolved or changed in that these bacteria utilize plastic as a food source. This dose not mean that the bacteria have evolved in the Neo Darwinian sense in that the bacteria have developed new information and proteins that didn't exist before.
Plastic have only existed for the last 70 years. It is most likely that the bacteria in question already had the information for producing the enzyme responsible for the digestion of the plastics. In fact the evidence is that the enzyme used to digest the plastics is a more general form of an existing enzyme. The existing enzyme has lost information and become less specific in function allowing it to help in the digestion of the plastic.
The bacteria produce an enzyme that breaks down the plastics into smaller molecules that the bacteria can use as food sources of carbon and energy. These bacteria have found a new niche and food source. This doesn't mean that the bacteria have developed a new enzyme.
Humans produce an enzyme that allows humans to digest and break down lactose sugars. In cultures where milk products are commonly used humans produce this enzyme in large amounts. In cultures where milk products are unknown or rare like pre Columbian Mexico, the production of this enzyme is less causing lactose intolerance.
In the same way the DNA code for the enzyme may have preexisted in the bacteria before the advent of plastics. In the presence of the plastic the bacteria adapted to the new food source by increasing the production of the enzyme or found a slightly different form of the existing enzyme.
The bacteria have evolved in the sense that they have been able to adapt to a new food source or niche. This does not mean that they have evolved in the Neo Darwinian sense of creating new information and becoming a completely new species.
