Archive · 9 Aug 2025
Science Answers: Did the Chicken or Egg Come First?
The age-old question of whether the chicken or the egg came first is answered by science!
Eggs, in a more basic form, existed long before chickens.
Animals developed amniotic eggs, which allowed them to lay eggs on land around 340 million years ago.
The first true chicken emerged from an egg with a genetic mutation laid by 'proto-chickens'.
The protein that makes the egg shell is found only in chicken.
Therefore the egg with the important mutation existed before the chicken itself.
This means, the egg that hatched the first chicken wasn’t exactly a chicken egg!
Eggs, specifically amniotic eggs, predate chickens by millions of years.
Amniotic eggs, with protective membranes, evolved around 340 million years ago.
The first chicken arose from genetic mutations in an egg laid by 'proto-chickens'.
Chickens may have diverged from red junglefowl around 58,000 years ago.
Ovocleidin-17 (OC-17), a protein unique to chickens, is key to making chicken eggshells.
- Who
- Scientists studying evolutionary biology and the ancestors of modern chickens.
- What
- The scientific explanation for the order of the chicken and the egg.
- When
- Eggs with protective membranes appeared around 340 million years ago; chickens evolved roughly 58,000 years ago.
- Where
- The article references the evolutionary timeline generally.
- Why
- To explain the evolutionary origins of chickens and eggs.
Egg Came First
Chicken Came First
Timeline
Egg Came First
Eggs, in the form of amniotic eggs, predate the existence of chickens.
Chicken Came First
The first chicken had to come from an egg which means eggs came first.
- Egg Type
- Amniotic
- Amniotic Eggs Timeline
- ~340 million years ago
- First Chicken Timeline
- ~58,000 years ago
- Chicken Ancestor
- Red Junglefowl
- Chicken Eggshell Protein
- Ovocleidin-17 (OC-17)