The chicken has a very impressive ancestor - the Tyrannosaurus Rex! Genetic evidence suggests that the chicken is the closest living relative of the famous carnivorous giant. Birds that would have been recognizable as chickens emerged from the evolutionary pool around 10 million years ago, 55 million years after the last T-Rex roamed the earth.
The bird from which all modern breeds of chicken descended is the Jungle Fowl (Gallus gallus). It was - and still is - a native of South east Asia. Approximately 5000 years ago these wild birds were first domesticated, for a combination of reasons - meat, eggs, cock-fighting, and various ritual practices (religious sacrifice and forms of fortune-telling involving 'reading the entrails', for example).
A White Sussex hen - one of the long-established breeds
The chicken's use as a meat and egg bird has given rise to dozens of breeds. Cock-fighting has a long-reaching legacy too, and several existing breeds owe their development to the dubious sport. Banned long ago in many US States and much of Europe on grounds of animal cruelty, the bloody sport is still popular in some parts of the world.
Chickens were widely kept in both Ancient Egypt and Ancient Greece, and Roman armies helped the bird spread to all corners of the Roman Empire. From its origins in the east, the bird's conquest of the West was now complete.
Because of its long history among humans, the chicken has been linked with all kinds of mythology and folklore through the ages. In Greek mythology it was a sacred bird of the Athena, goddess of wisdom and warfare, a bird of fertility for Persephone, a clucking token of love and desire for Eros, and a symbol of commerce and productivity for Hermes. So sacred was it, in fact, that Ancient Greeks didn't eat chicken meat, keeping the birds for eggs and religion only!
To the Romans and to many pagan European religions, the cockerel was linked to the sun, whose daily rising it celebrates with the kind of crowing that has made chickenless neighbors swear for several centuries! Whole books have been written about chicken folklore; and no book of folk tales would be complete without its Little Red Hens, Chicken Lickens and Henny Pennys. This is a bird that has captured our imaginations, our hearts and our dinner plates - quite a combination!
Chickens were soon free-ranging across the globe
It was in the nineteenth century that chicken breeding began with a vengeance. Breeders took existing birds and developed new types, some aiming at better egg production, others at better meat, and plenty more going for good looks alone. One of the catalysts was British monarch Queen Victoria, who kept and bred chickens - and, interestingly, was responsible for the new mood of animal rights and moral reform that spread from England cross the world from the 1820s. Victoria's government banned cockfighting in 1849, and it is now illegal in all States of the US (although it remains legal in some US territories, notably Puerto Rico and Guam, which have long, Spanish-derived traditions of the blood sport).
By the end of the nineteenth century there were countless poultry clubs, competitions, exhibitions and dedicated chicken breeders. Some of the best birds were sold for hundreds of dollars at auction.
The twentieth century saw mass production of chicken meat transform the diet of millions. Chickens became the Earth's commonest species, with numbers translating to more than one bird for every human on the planet.
Sadly, not all the innovations in chicken breeding were positive, with factory-bred birds soon containing more unhealthy fats (due to their diets) than red meat, not to mention a cocktail of growth hormone and antibiotics. Animal welfare has been a major issue too. On a more hopeful note, the end of the twentieth century saw the beginnings of change in the system of food production, powered by a growing health and nutrition lobby and a growing army of consumers looking for organic and other healthy, ethical food products.
The next natural step is to keep your own chickens, where their diet and welfare is in your capable hands!