The genetic change that caused peppered moths to become dark in the UK during the industrial revolution has been traced. As it turns out, it's the same gene that controls the colours of the Heliconius family of tropical butterflies. "Scientists have discovered the specific mutation that famously turned moths black during the industrial revolution.
In an iconic evolutionary case study, a black form of the peppered moth rapidly took over in industrial parts of the UK during the 1800s, as soot blackened the tree trunks and walls of its habitat.
Now, researchers from the University of Liverpool have pinpointed the genetic change that caused this adaptation.
They have also calculated the most likely date for the mutation - 1819.
Their study appears in the journal Nature, alongside a second paper, which describes how the same gene allows tropical butterflies to switch between different colour schemes.
The second Nature paper concerned with the cortex gene explores its role in the Heliconius family of tropical butterflies.
Dr Nicola Nadeau from the University of Sheffield was the first author of that study. "It's amazing that the same gene controls such a diversity of different colours and patterns in butterflies and a moth," she said.
Her findings implicate cortex in the Heliconius butterflies' unusual habit of exchanging DNA and mimicking each other's dramatic colouring, which helps ward off predators."