The pig (Sus scrofa) is a member of the artiodactyls, or cloven-hoofed mammals, which are an evolutionary clade distinct from the primates and rodents. Pigs exist in both feral and domesticated populations that have distinct phenotypes and karyotypes. The haploid genome of the domesticated pig is estimated to be 2800 Mb. The diploid genome is organized in 18 pairs of autosomes and two sex chromosomes.Sus scrofa is an important model organism for health research due to parallels with humans. Swine are omnivores and their digestive physiology is similar to humans. Similarities between humans and pigs also exist in renal function, vascular structure, and respiratory rates. Pigs are used as model organism in many areas of medical research including obesity, cardiovascular disease, endocrinology, alcoholism, diabetes, nephropathy, and organ transplantation. Pigs are also agriculturally important, as pork is a leading source of protein worldwide.