Species homogeneity
In ecology, species homogeneity is a lack of biodiversity. Species richness is the fundamental unit in which to assess the homogeneity of an environment. Therefore, any reduction in species richness, especially endemic species, could be argued as advocating the production of a homogeneous environment. Monocultures Homogeneity in agriculture and forestry; in particular, industrial agriculture and forestry use a limited number of species. About 7,000 plants (2.6% of all plant species) have been collected or cultivated for human consumption. Of these, a mere 200 have been domesticated and only a dozen contribute about 75% of the global intake of plant-derived 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 migration 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