Chicken or egg

Which came first, the chicken or the egg

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Chicken eggs. image: wikipedia

This is a common philosophical dilemma and commonly described in wikipedia as :

“ The chicken or the egg causality dilemma is commonly stated as "which came first, the chicken or the egg?” 

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recently hatched chickens. image: R.Conan-Davies

To ancient philosophers, the question about the first chicken or egg also evoked the questions of how life and the universe in general began. 

Cultural references to the Chicken and Egg intend to point out the futility of identifying the first case of a circular cause and consequence. 

It could be considered that in this approach lies the most fundamental nature of the question. 

A literal answer is an egg according to some people, as egg-laying species pre-date the existence of chickens. To others, the chicken came first, seeing as chickens are merely domesticated Red Junglefowls. However, the metaphorical view sets a metaphysical ground to the dilemma. 

To better understand its metaphorical meaning, the question could be reformulated as: "Which came first, X that can't come without Y, or Y that can't come without X?”

Source adapted from Chicken or the egg. (2015, January 15). In Wikipedia, The Free Encyclopedia. Retrieved 08:37, January 22, 2015, from http://en.wikipedia.org/w/index.php?title=Chicken_or_the_egg&oldid=642658328


Evolutionary argument

From an evolutionary life perspective the chicken came first.  The reason is because  a few hundred million years there was a common ancestor to a chicken, a creature that shares common features of a chicken. This proto creature reproduced most likely by binary fission (splitting) similar to a euglena or a hydra, a single celled creature.

But how did this single celled creature become multicelluar?

One idea for the formation of  multiceullular creatures, like the ancestors of chickens, is the colonial flagellate hypothesis[wikipedia].  This creature then goes onto evolve a few specialised cells that go onto become egg cells. 

The first eggs didn’t have a shell because they were still in the ocean. 

But evolution led to a genetic variation that allowed for a shell gene to form so that the first sea creatures could get their eggs on land to avoid being eaten or drying out for example.  Through a chain of evolution a creature like an chicken forms (dinosaurs is the current accepted theory). Although this may suggest that chickens come from eggs, the first egg evolved from a non egg laying creatures.

So it really depends on how to define ‘chicken’ and ‘egg’. If chicken is taken as any common ancestor of chickens then it still suggests the chicken came first in a generic sense.  But if  ‘chicken’ is taken as the common chicken [Gallus galls domestics]. Then there would be an egg first with unique characteristics that are specific to Gallus .