There have been various explanations explaining the origin of chickens. Charles Darwin?s studies concluded that the domestic chicken originated from the red jungle fowl. However, a new study from University of Uppsala suggests that Darwin was wrong. The first domesticated chickens originated in India and East Asia around 7000 BC. The first historical reference to?chickens?may have occurred in Mesopotamia around 2000 BC.
Mapping of genes that give rise to yellow legs in domesticated chicken was researched. This led to the discovery that the genetic heredity of chickens originates from the gray jungle fowl. Studies show that despite the red jungle fowl contributing the most genes to the domesticated chicken, contribution by another species should have been made: the gray jungle fowl.
The genes that contribute to yellow skin are widely spread among millions of domestic chicken around the world. One researcher concluded that the yellow in the legs is brought about by the type of feed. The more yellow the carotenoids are in the chicken food, the more yellow the legs.
The gene responsible for coding an enzyme that breaks down carotenoids is inactive in skin but active in other organs in chickens with yellow legs. Consequently, the yellow carotenoids stay in the skin in these chickens. This is referred to as a regulatory mutation due to the modification of the gene sequence which is intact.
It is still not understood why humans bred chickens with this trait of yellow legs. The same gene can be important when elaborating the flamingo?s pink color, salmon?s reddish meat and birds of prey?s yellow legs. Carotenoids are responsible for these characteristics.
A literal answer to the question of ?Where do chickens come from?? as far as commercial production is concerned is a metal shed. Almost all chicken meat consumed comes from a farm. Some of the conditions are very undesirable, and this is why buying free range birds are best for your family?s diet. 94% of chicken production comes from rearing of birds. Continuous filming is done to record important statistics like water intake, food intake, and the weight of the birds.
Egg production and meat production are two different industries. For a while now, farmers have reared broilers for meat and layers for eggs. Eggs are fairly cheap, and free range chicken breasts are fairly affordable, making chickens an important staple in the diet of millions of people.