Egg came first or the chicken?

The chicken or egg causality dilemma has been there with mankind for some time now.  The moot point here is not the term in itself but its actual usage.  There could be two interpretations – it could be either trying to find out the actual cause of a circular dependence or maybe it is really about whether the hen/chicken (Gallus gallus domesticus) came first or whether the egg from which it took birth came first.

Now, the first interpretation is pretty self intuitive as there could be many scenarios in daily life where we might have two events which could be plausible reasons of each other. It could be equally applicable to scientific theories or principles Van der Waals equation or Colebrook equation where one equation would be dependent on a certain parameter which could itself only be derived from the said equation.

Now, let’s take a look at the second interpretation.  I for one, all this while thought that no one was ACTUALLY bothered about the literal chicken or its egg and it dependency on each other. And I was least expecting that a team of researchers would actually go about finding the answer to this dilemma. I was pretty much baffled when I found this news article about two British researchers finding an answer to the age old problem. Let me summarize the research results for you.

“Scientists have long believed that a chicken eggshell protein called ovocledidin-17 (OC-17) must play some role in egg shell formation. The protein is found only in the mineral region of the egg (the hard part of the shell) and lab bench results showed that it appeared to influence the transformation of (CaCo3) into calcite crystals. The mechanism of this control remained unclear. How this process could be used to form an actual eggshell remained unclear.

Dr David Quigley from the Department of Physics and Centre for Scientific Computing, University of Warwick, said: “Metadynamics extends conventional molecular dynamics (MD) simulations and is particularly good at sampling transitions between disordered and ordered states of matter.”

Using these tools, the team was able to create simulations that showed exactly how the protein bound to amorphous calcium carbonate surface using two clusters of “arginine residues”, located on two loops of the protein and creating a literal chemical “clamp” to nano sized particles of calcium carbonate.”

With due respect to the researchers as well as my limited knowledge of biology (Indeed I took my last biology class way back in 1999 when I was in 10^th standard), I would beg to differ. First things first – If the chicken is able to produce OC-17 , then we all know that even other birds have their very own eggs and there must be some protein even their eggs must be relying upon. So protein is not important. As a matter of fact, the protein is being produced in chicken’s body because of some natural processes which obviously the chicken is not in control of. Neither was it ancestor – Red Junglefowl (Gallus gallus). Here, let me touch upon my favorite topic – evolution.

Birds or aves evolved during Jurassic period from theropod dinosaurs and are the last living representatives of dinosaurs. And indeed the dinosaurs too gave birth through eggs. So lets change the topic to did the dinosaur come first or the egg? Here again, Dinosaur was not the first egg laying animal of course. Dinosaurs had evolved by about 230 million years ago, but before that the reptiles (the class to which superorder dinosauria belongs, 320-310 million years ago) also used to give eggs. Can we stop at reptiles then? Yes and No.

No because eggs are not a specialty of reptiles as reptiles evolved from earlier vertebrates like fish who also give eggs. In fact, it is said that all vertebrates (excepting mammals and marsupials) give eggs. Vertebrates are the set of animals (a subphylum of chordates to be precise) who are known distinctly by their backbones (could be cartilage also as in the case of shark).  But as far as I know, earlier invertebrates specially arthropods like crustaceans and insects also give birth through eggs. The time I am talking about is 540 million years ago.

Yes because reptiles are the first type of animals who came out with a calcium covered egg, i.e. the kind of egg which can be protected to some extent from the forces of nature and which can sustain the embryo life inside for a considerable period of time.

The poor chicken which is already carrying the burden of billions of people world over by becoming a part of their meal day in and day out is thus being thrusted upon with the extra responsibility of egg origins. Whereas the actual culprits are early reptiles.

So I would like to conclude by saying that the common man should not be mislead into believing that actually the chicken came first and stuff like that. I firmly believe though that the intention of the researchers was never to solve the egg chicken problem but to find out how to promote and control artificial forms of crystallization which would go a long way in bone formation and related research.