When did chickens start laying eggs?

This is a tricky question! Here's why:

* Evolution: Chickens evolved from a long line of bird ancestors. The ability to lay eggs predates the existence of chickens by millions of years. So, in a sense, chickens have *always* been laying eggs, just not as the chickens we know today.

* Domestication: Domestic chickens are a specific breed selectively bred for egg production. The exact timeline of when chickens were domesticated and egg production was prioritized is still debated. However, it's likely that chickens have been laying eggs for humans to collect for at least 5,000 years, possibly even longer.

So, there's no one definitive answer! We can say that chickens have been laying eggs for a very long time, both in their evolutionary history and in the history of human interaction with them.