Black Peppered Moths Bizaare Color Attributed to Industrial Revolution
Ever wondered where the black peppered moth got its color? Apparently, this winged creature is keeping a dark secret.
According to Smithsonian, the black peppered moth originally sports a white and black color. However, over the years, these moths shed their white pigments and turned completely black. Two studies published in the journal Nature reveal that the cause of this sudden change in pigmentation is industrialization.
One of the studies discovered that the change of color among black peppered moths dated back in 1819, when burning coal was widely used to for energy to fuel industrial machines in Europe. In order to survive and camouflage, the once black-and-white moths adapted the color of coal to hide from possible predators.
The second study reveals that moths, as well as butterflies, contain a gene that allows them to change color over time. This change in genetic makeup was passed on over generations, making the black peppered moths common today.
"When I started working on it I was surprised, given how well known it is, that no-one had actually tried to... characterise the underlying genetics controlling the physical appearance of this moth," Dr. Ilik Saccheri from the University of Liverpool, the scientist responsible for the second study, said.
Saccheri has been studying black peppered moths for 15 years now and said that what happened to these moths is an example of how quickly evolution could occur.
"It's a graphic example of rapid evolutionary change. In the days before we could track mutation and change in bacteria and viruses, there weren't many examples of visible change within a human lifetime," Saccheri said as quoted by BBC.
Through millions of simulations, Saccheri and his team discovered that the gene responsible for this color change is hidden in transposons or "jumping genes," which can copy and paste themselves as well as jump from genome to genome. However, the process of identifying this gene was not an easy task. The researchers started with traditional gene mapping by crossing black and pale moths, tracking each chromosome that's linked to the moth's black pigmentation.
"We knew that within that 400,000 bases, there was some sequence that had to... cause the actual difference between the black type and the typical type,"
After a long and painstaking process, they were able to identify the "jumping gene" or transposons. And because of the peculiar nature of transposon mutation as well as natural selection, the study says that this might not be the end of the black peppered moth's mutation. It could change its color again as it adapts to the changing environment.