Around 200 years ago, the peppered moths of England were readily identifiable by their black-speckled white wings, which camouflaged well with pale tree bark. But after the Industrial Revolution, when pollution from coal-powered factories darkened the trees, black wings came to dominate the population.
This story about the dark-winged peppered moths is now considered a textbook example of natural selection. However, it wasn’t until 2016 that researchers uncovered the genetic mechanism behind the wardrobe change. By sequencing hundreds of peppered moth genomes, the geneticists found a significant and consistent difference in a gene called cortex involved in wing development. A transposon, absent in the white-winged moths, had been inserted into the beginning of this gene in nearly all the black moths and had led, through an unknown mechanism, to the production of dark-colored wings.
How Virus-like ‘Jumping Genes’ Became Our Partners in Evolution https://www.quantamagazine.org/how-virus-like-jumping-genes-became-our-partners-in-evolution-20260921/
Quanta MagazineHow Virus-like ‘Jumping Genes’ Became Our Partners in Evolution | Quanta MagazineHalf of our genome is made of transposons — snips of DNA that can move and copy themselves. But they’re more than parasites or genetic junk.