University’s scientists Utah explained the riddle, which depends on the length of pigeon bears, which Charles Darwin described in his book about evolution and origin of species as an illustration of natural selection. This is reported in the article published in the journal Current Biology.
Researchers found that mutation in the ROR2 gene makes short beaks in many breeds of homemade pigeons. Mutations in ROR2 also underlie the human disorder called Robin syndrome and which is a vice maxillofacial area. The syndrome is characterized by the emergence of such specific features of the face, as a wide protruding forehead and short lower jaw and nose. These signs resemble a phenotype in short-frozen pigeons.
Scientists brought two pigeons with a short and middle beak belonging to different rocks. The female was the old German seagull (Old German Owl), and the male referred to the racing Mail Poland (Racing Homer). Their offspring F1 had medium length keys. After crossing the light, the proceedings F2 appeared with the beaks of different lengths. Researchers have determined the exact size and form of beaks in 145 individuals from this group using microcomputer tomography. It turned out that along with the size of the beak also changes the shape of the skull.
Comparison of genomes showed that individuals F2 with small beaks had the same part of the sex chromosome as their grandmother with a small beak. The analysis of the full sequences of the genome of many different breeds of pigeons demonstrated that all birds with small beaks had the same DNA sequence in the genome area containing the ROR2 gene. The authors suggest that the mutation in the gene causes the ROR2 protein to develop in a new way, but scientists plan to carry out additional experiments to find out how mutation affects the cranial development.