Mouflon vignei" (or "orientalis") "arkal" and "O. v./o. bochariensis", grouped with two different clades of argali ("Ovis ammon"). The ancestral sheep is presumed to have had 60 chromosomes, as in goats ("Capra"). Mouflon and domestic sheep have 54 chromosomes, with three pairs (1+3, 2+8, 5+11) of ancestral acrocentric chromosomes joined to form bi-armed chromosomes. This is in contrast to the argali and urial, which have 56 and 58 chromosomes respectively. If the urial is as closely related to the mouflons as mitochondrial DNA indicates, then two chromosomes would need to have split during its evolution away from the mouflon (sub)species. In
Species homogeneity calories. 95% of world consumption of protein derives from a few domesticated species, i.e. poultry, cattle and pigs. There are about 1,000 commercial fish species, but in aquaculture fewer than 10 species dominate global production. Human food production therefore rests on the tips of pyramids of biodiversity, leaving the majority of species not utilised and not domesticated. Species naturally migrate and expand their ranges, utilising new habitats and resources, e.g. the cattle egret. These natural invasions, an incursion in the absence of anthropogenic influences, occur "when an intervening barrier is removed, or through the development of biotic or abiotic transportation