The modern domesticated turkey has its roots in southern Mexico, with the first evidence of domesticated birds popping up in the archaeological record between 200 B.C. and 500 A.D. Early European settlers would have seen the turkey as a common North American bird. Like wild turkeys today, these birds were dark in color, sporting barred white feathers with a green and bronze iridescent sheen. They were sleek and quick, and could fly short distances when they needed to.
Run the clock forward and generations of breeding domesticated turkeys have produced birds that are twice as big and stark white. Because of their oversized, heavy breasts they cannot fly. Many commercially raised turkeys on industrial farms cannot even mate properly, leaving the turkey industry almost completely dependent on artificial insemination. Why have we seen such changes? Consumer demand and technological innovation.
Turkeys with large breast and thigh muscles are prized by farmers because they’re the most valuable parts of the bird at sale. Birds that presented these traits were selected to breed by farmers, increasing the size of birds through generations.
The color of the birds changed too -- dark colored pin feathers left over from plucking are far less desirable to the consumer than a clean stretch of pink skin. Technological advances in artificial insemination in the 1930s and '40s allowed for prized male turkeys' semen to be distributed more widely among hens, allowing for generations of turkeys to be bred larger at a faster rate. The average turkey today grows to be twice as heavy as a turkey in 1960, and in half the time. Your store-bought Thanksgiving turkey may not look it, but it’s a genetically engineered modern marvel.