What came first? Chicken or an egg? Science finally has an answer

One of the earliest and most often debated questions among human beings of all time is about which one came first! The chicken or the egg? To solve this it is necessary to turn back to history and evolutionary origins of chickens

Broadly, eggs are found throughout the animal kingdom. Technically, an egg is a membrane-bound container in which an embryo can develop into an independent being. These eggs first appeared with the evolution of the first amniotes many millions of years ago. Before the appearance of the first amniotes, most animals reproduce in water; they laid their eggs in ponds and other moist habitats to keep them from drying out.

Evolution of amniotic eggs
At some point, there was a new sort of egg, this time with three more membranes within it: chorion, amnion, and allantois, which began to evolve. Although each membrane has its specific function, when put together, these envelop an integrated, all-in-one life support system. This new structure allowed embryos to take in stored nutrients, store waste products, and respire, making it possible for animals to lay their eggs on land.

Occurrence of the first chicken
According to the Australian Academy of Science, The very first chicken would have been the result of a genetic mutation (or mutations) occurring in a zygote produced by two proto-chickens. This means that two proto-chickens mated, combining their DNA to form the very first cell of the very first chicken. During this process, genetic mutations occurred in that initial cell, and these mutations were then replicated in every subsequent cell as the chicken embryo developed and resulted in the first chicken.

According to research, the amniotic eggs made their debut roughly 340 million years ago and the first chickens evolved around 58,000 years ago at the earliest, it’s reasonable to assert that the egg came first. Amniotic eggs existed long before chickens did, providing the necessary environment for various animal embryos to develop.

Chicken eggs have a special protein
However, there is one specific protein called ovocleidin-17, or OC-17, which exists only in the ovary of a chicken. Scientists concluded that the chicken must have preceded the chicken egg because OC-17 was necessary for the formation of an eggshell. This protein accelerates the process of forming the eggshell so hens can build their egg from scratch and can lay them in 24 hours.

What really came first?
So ultimately the argument comes back to that age-old riddle. While there can be no denying that eggs in general predate chickens, the specific formation of chicken eggs involves the presence of chickens to produce the necessary protein. Thus it is important to note that the chicken and the egg are mutually dependent. Therefore, chicken eggs are intrinsically tied to the existence of chickens themselves.

Evolutionary Perspective
From an evolutionary standpoint, the egg came first. This idea is grounded in the theory of evolution, which explains how species change and develop over time. Birds, including chickens, evolved from reptiles millions of years ago. Early reptiles laid eggs, and over countless generations, genetic mutations and natural selection led to the emergence of birds.

At some point, a bird species very similar to a chicken laid an egg, and due to a genetic mutation during fertilization, the first true chicken hatched from this egg.