House Sparrows are closely associated with humans and are found in most parts of the world. By investigating the DNA of several species of sparrows, researchers have shown that the House Sparrow diverged from a sparrow in the Middle East – and started to digest starch-rich foods – when humans developed agriculture some 11,000 years ago.
The house sparrow (Passer domesticus), is a very familiar bird species. If you walk down the street of any major European town or city, you will see them hopping back and forth, picking up scraps of food and nesting in nearby buildings. They are also a common sight on farms and in the countryside. Our connection with sparrows goes further – they are mentioned in the Bible, in Chaucer's The Canterbury Tales and Shakespeare's Hamlet.
How is it that this small, charismatic bird has become so closely associated with us?
Researchers at the Centre for Ecological and Evolutionary Synthesis (CEES) at the University of Oslo (UiO) have been trying to answer this question by investigating the DNA of populations of House Sparrows from across Europe and the Middle East. Teaming up with colleagues from Iran and Kazakhstan, they also investigated the Bactrianus sparrow, a subspecies found only in these regions.
The Bactrianus sparrow looks like a House Sparrow, but is wild, avoids human contact and feeds on a very different diet. By comparing the DNA of the two sparrows, the team hoped to gain some insight into why one evolved to be closely associated with people while the other did not.