The so-called causality dilemma – which came first, the chicken or the egg – is based on the fact that we cannot be certain what the cause is and what the effect is. A chicken is required to lay the egg, which also means that the egg which hatched the chicken had already existed. Logically, this is an infinite regression, which, at a glance, does not yield answers. However, you may be surprised that many philosophers and also biologists down the lane, answered this dilemma, but to this day, there is no solution which everybody acknowledges.
A chicken is a chicken, there is no particular dilemma there. It is the most common bird in the world – currently, there are more than 20 billion of them living on the planet. The chicken breed, which apart from our chickens, includes peacocks, quails, pheasants, and others, originates from birds that survived the impact of a giant asteroid that eradicated the dinosaurs and numerous other species.
It is presumed that about 66 million years ago, a gargantuan asteroid of about 10 kilometres in diameter, hit the Earth in what is now known as the Gulf of Mexico, and created the 180 km wide Chicxulub crater. The catastrophic impact decimated all living beings in a radius of several hundred kilometres, followed by volcano eruptions and a series of earthquakes. So much dust and soot went up in the air that the Sun was veiled for months and years, causing the climate on the Earth to drastically change for at least a decade.
Two-thirds of all living species became extinct. Almost all vertebrates weighing more than 25 kg died out, excluding some turtles and crocodiles. Bearing in mind that the impact destroyed forests across the globe and that in the following 100 years, mostly fern thrived on the Earth, almost all birds living in the trees shared similar destiny. Birds that lived close to the ground or water survived, including chicken ancestors.
Chickens similar to modern ones are presumed to have developed around 58 thousand years ago, but these were wild birds which humans proceeded to domesticate, having already done that with cattle and other animals. Domestic chickens are possible to have descended from the still-living red junglefowl (Gallus gallus) which inhabit Asia. The chicken was famous in Ancient Egypt as ’a bird which gives birth every day,’ and Ancient Greeks used them in cockfights.
Eggs are, however, a different story altogether. Animals produce gametes for reproduction – egg cells and sperms which create a new life in the process of fertilization. Laying eggs externally (oviparous reproduction) occurs throughout the animal world, in birds, some reptiles, and some arthropods. So, their egg is a reproductive cell which is wrapped in a membrane (shell) before or after fertilization. During the incubation period, an embryo develops inside the egg, and if things go well, in optimum conditions, a new being will hatch from the egg.
Since eggshells decompose easily, there are no good fossil findings which could help define when the first oviparous animals, which lay eggs on the land, lived, but it is thought it was circa 370-340 million years ago.
Therefore, if we pose the question of which came first – the chicken or the egg – no matter which egg is in question, even the one which hatched, for example, a dinosaur, then it is quite easy to answer that eggs came first by millions of years.
However, the dilemma certainly does not end here. The first chicken in the world is the result of a chance gene mutation in a zygote (a fertilised egg cell), which occurred by mating two ’proto-chickens’, birds which are ’almost chickens’. By combining their DNA material, they created the first cell of the first chick, which mutated and multiplied until a chicken embryo developed. Seemingly, this egg, which nested the first chicken, is older than the first chicken itself.
Yet, more recent findings have additionally complicated the matter. It has been revealed that the eggshell, which is composed of calcium carbonate, was formed by our proto-chicken producing a special OC-17 protein in the womb, which enables hard membrane formation. So, the shell is formed by our proto-chicken and not the chick in the egg. These are the materials of the proto-chicken, not of the chick. Thus, it was the proto-egg which hatched the first chicken. Only the first chicken could have laid the real chicken egg. Ultimately, it looks like the chicken came first.
Not everybody agrees on this, so this could go on and on for ages.
The ancient riddle on what came first was posed by Aristotle in a way, wondering what came first, potentiality or actuality. Although he did not define it as we did, Aristotle would certainly resolve the chicken and egg dilemma by answering that the chicken came first. Ancient Greek philosopher, historian and writer Plutarch, who lived in 1 century AD, also discussed this question in one of his essays, stating, as a stalwart vegetarian, that it was equally immoral to eat an egg and the animal which hatched that egg. Plutarch put the question of what had come first by comparing it to the question of whether the world had a beginning.
At the end of his discussion, Plutarch mentioned that, in the end, a bird first built a nest before laying the eggs, and a woman first prepared a crib, but still, no one concluded that the nest came before the egg, or the crib before the baby. He concluded that a seed or an egg could not beget before an animal was formed, and that the seed might strive to become a principle, but that this was impossible for an egg because it did not have the nature of a whole since it was imperfect.
M.Đ.
Illustration: Adolphe Millot, Nouveau Larousse Illustré (1897)/Wikimedia commons