Here's a fact to keep in mind as you pile your plate with Thanksgiving turkey: The bird we roast and enjoy these days looks almost nothing like the turkey your grandparents ate.
The average turkey weighed 13.2 pounds before slaughter in 1929. By 2013, that number had more than doubled to 30.3 pounds.
In the 1940s, farmers started using artificial insemination to select for the turkeys with the biggest breasts. The practice took off, and today's turkeys are so big they have trouble standing upright and have lost the ability to fly.
Check out the video above to learn more about how turkeys went from svelte to supersize.