Stages of Chicken Egg Development A chick emerges from an egg after three weeks (21 days) of incubation. Soon after incubation begins, a pointed, thickened layer of cells becomes visible in the ...

This embryo development process followed very particular stages known to be remarkably similar between animal species. ... Scientists Finally Solve the ‘Chicken or Egg’ Mystery.

Technically, the chicken that we know today came about after our amniote pals switched to laying hard-shelled eggs. Regardless of if the chicken or egg came first, these researchers have peeled ...