Another Icon of Evolution falls - the Peppered Moth

The article "The industrial melanism mutation in British peppered moths is a transposable element" by Van't Hof et al. (2016) provides evidence that the mutation that caused industrial melanism in peppered moths was a transposable element. Transposable elements (TEs) are pieces of DNA that can move around the genome. They are often called "jumping genes". TEs can cause mutations by inserting themselves into genes, disrupting their function. TE's are outside of NeoDarwinism as they are noncoding DNA. This means if a mutation occurs to them they will not be selected for.

In the case of the peppered moth, the transposable element inserted itself into the gene cortex. This gene is involved in the production of melanin, the pigment that gives moths their color. The insertion of the transposable element caused the moths to produce more melanin, making them darker. This means NeoDarwinism was not the cause of this change.

The increase in melanin pigmentation made the moths more camouflaged against the darkened trees in industrial areas. This reduced the risk of the moths being eaten by birds, giving them a selective advantage. As a result, the frequency of the carbonaria (dark) morph of the peppered moth increased in industrial areas.

The discovery that the industrial melanism mutation was caused by a transposable element challenges the traditional view of evolution, which is based on the theory of natural selection. Natural selection is the process by which organisms with advantageous traits are more likely to survive and reproduce, passing on their genes to the next generation.

In the case of the peppered moth, the transposable element insertion was a random event. It did not confer any immediate advantage to the moths. However, the moths that were heterozygous for the mutation (i.e., they had one copy of the normal allele and one copy of the mutant allele) were more camouflaged against the darkened trees. This gave them adaptive advantage (not natural selection) over the moths that were homozygous for the normal allele.

Over time, the frequency of the carbonaria morph increased in industrial areas. This is because the moths with the mutation were more likely to survive and reproduce. However, it is important to note that the mutation itself (NeoDarwinism) did not confer any advantage to the moths. It was the interaction between the TE and the environmental change (i.e., the industrial pollution) that caused the moths to evolve.

The discovery that TEs can cause adaptive changes challenges the traditional view of evolution in two ways. First, it shows that evolution can be driven by random events, not just by natural selection. Second, it shows that evolution can be caused by changes in the genome that do not confer any immediate advantage to the organism.

The discovery of TEs has also led to the development of new theories of evolution. One of these theories, called "evolvability theory", focuses on the mechanisms that allow organisms to change their genomes. Evolvability theory argues that the ability to change the genome is essential for evolution.

Another theory, called "punctuated equilibrium", argues that evolution does not happen gradually, but in fits and starts. Punctuated equilibrium theory argues that TEs can cause rapid changes in the genome, which can lead to new species.

The discovery of TEs has had a major impact on our understanding of evolution. It has shown that evolution is a more complex process than previously thought. It has also shown that TEs can play a significant role in evolution.

In conclusion, the article "The industrial melanism mutation in British peppered moths is a transposable element" provides evidence that TEs can cause evolution without NeoDarwinism. This challenges the traditional view of evolution, but it also opens up new possibilities for understanding how evolution works.