A recent study has found that most modern day pigeons have descended from racing birds in the Middle East that escaped captivity. The research, which was recently published in the journal Science, was conducted using extensive DNA studies of the rock pigeon, which much of the world just calls “pigeon.”
In comparison to mammals and fish, little research has been done in regards to the genetic make-up of bird species. Despite this, Michael Shapiro, a principal author on the research and an assistant professor of biology at the University of Utah, believes learning more about birds through genetic studies is very important.
“Birds are a huge part of life on Earth, and we know surprisingly little about their genetics,” Shapiro said in a press release. “There are more than 10,000 species of birds, yet we know very little about what makes them so diverse genetically and developmentally.”
Using software developed by study co-author Mark Yandell, a University of Utah professor of human genetics, the scientists were able to isolated a single mutation in a gene named EphB2, which they say causes head and neck feathers to grow upward instead of downward, creating head crests. It was this gene that allowed them to match the pigeon genome to those of chickens, turkeys and zebra finches.
The study assembled 1.1 billion base pairs of DNA in the rock pigeon genome, and the researchers believe there are about 1.3 billion total, compared with 3 billion in the human genome. The rock pigeon’s 17,300 genes compare with about 21,000 genes in people.
Shapiro believes the research he and his team did on pigeons is a step in the right direction. “We’ve shown a way forward to find the genetic basis of traits — the molecular mechanisms controlling animal diversity in pigeons,” he said. “Using this approach, we expect to be able to do this for other traits in pigeons, and it can be applied to other birds and many other animals as well.”
Pigeons have been domesticated for over 5,000 years, which is longer than any other bird species. Despite their reputation as pesky city dwellers, pigeons are actually quite intelligent. In fact, they were once used as homing pigeons and were beloved for their beauty.
The study found that there are approximately 350 different breeds of pigeon, all with unique characteristics. The research team also discovered that the most common types of pigeon originated in the Middle East. According to the scientists, pigeons in North America are closely related to racing pigeons, which were called racing homers.
With the completion of this research, the pigeon joins the chicken, turkey, zebra finch, and common parakeet as the only free birds whose full genomes have been sequenced. Pigeons are the world’s oldest domesticated birds, with a history with humans that goes back thousand of years, yet scientists have struggled to document the bird’s evolution. According to Shapiro, “this will give us new insights into bird evolution.” That’s not all these sequenced species have in common. “Despite 100 million years of evolution since these bird species diverged, their genomes are very similar,” Shapiro said.
The scientists also studied other breeds of pigeons, some which they believe originated in India. It is thought that while people in India during Fertile Crescent times were trading goods, they were also interbreeding their pigeons giving rise to new breeds.
Shapiro is excited about what the new research could mean for bird research, noting that Charles Darwin had a soft spot for pigeons. “Now we can get to the DNA-level changes that are responsible for some of the diversity that intrigued Darwin 150 years ago,” he said.
While it may seem odd to study such a familiar bird, pigeons have long captured the fascination of scientists. The father of evolution, Charles Darwin, bred pigeons at his home with the intent of studying their evolution. He wrote about them extensively in his books on natural selection and evolution and speculated, along with others, that the 150 breeds known at the time all descended from the rock dove, according to historians.
The study is slated for publishing on January 31 in the Science journal’s website Science Express.