Liz Scheltens
is a senior editorial producer for the Vox video team.
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 has more than doubled in size since 1929.
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.