Small segments of rice genome sequence have been compared with that of the model plant Arabidopsis thaliana and with several closer relatives, including the cereals maize, rice, sorghum, barley and wheat. The rice genome is relatively stable relative to those of other grasses. Nevertheless, comparisons with other cereals have demonstrated that the DNA between cereal genes is highly variable and evolves rapidly. Genic regions have undergone many more small rearrangements than have been revealed by recombinational mapping studies. Tandem gene duplication/deletion is particularly common, but other types of deletions, inversions and translocations also occur. The many thousands of small genic rearrangements within the rice genome complicate but do not negate its use as a model for larger cereal genomes.