Domesticated species and the human populations that domesticate them are typified by a mutualistic relationship of interdependence, in which humans have over thousands of years modified the genomics of domesticated species. Genomics is the study of the structure, content, and evolution of genomes, or the entire genetic information of organisms. Domestication is the process by which humans alter the morphology and genes of targeted organisms by selecting for desirable traits. These genomic changes produce the domestication syndromes. Since domestication involves selection of traits over time, which leads to genetic changes, the science of genomics can identify which genes across an entire genome are altered during this intense artificial selection period. Understanding the genomics of domestication can also offer insight into the genetic effects of both the artificial, human driven selection of domestication, as well as natural selection. This makes the genomics of domestication a unique tool for examining the genetics of evolution in organisms that are relatively easy to study as their history may be more thoroughly preserved due to their usefulness to humans. Historically genomic studies have been focused on select organisms for which there is funding to study. Initially, when sequencing costs were prohibitive, this was limited to organisms with small genomes, such as viruses and bacteria, and then in eukaryotes, model organisms of importance to the scientific community for research. These included the Mus musculus (the house mouse), Drosophila melanogaster (fruit fly) and Arabidopsis thaliana (Arabidopsis) genomes. One of the most prominent publicly funded genome projects was the Human Genome Project which helped to refine existing sequencing techniques as well as develop additional ones. Following these model organisms, agriculturally important species were next emphasized. As of 2009, there are more than 50 plant species whose genomes are being sequenced.