What came first — Egg or Chicken?

Recently, in an effort to bamboozle his biochemist fiancee, my brother-in-law asked the perennial question:

What came first? Egg or Chicken?

She, a bit excited, quickly responded (simplified version):

Before start of life, there were simpler molecules, which lived by the laws of chemical reactions. At one point of time, some molecules formed a chain to encircle other set of molecules and thus forming a cell and cell lining to create earliest living beings — protobionts.

Next came the beautiful logic.

As protobionts were the earliest living beings created purely from the non-living things, hen came first.

Now, the rebuttal!

Is egg a living being? Answer is no. With this, we arrive at the following analogy :

Just like chicken is created from a non-living egg, protobionts were created from non-living things which can be taken as it’s the egg.

Hence, protobionts were created from an egg and we are at square one again. Also, at the same time, it does not answer the question in entirety. It does not take into account that egg is in turn created by chicken itself. We try to modify the question as:

There are two things — one living and another non-living (chicken & egg) who are procreating the other. How do we say which one created the other first?

To satisfy the question, we move to a point where organism are still single cell. In simplest form of multiplying, it grows by consuming matter till it grows big enough to splits into two halves.

Hence, single cell organism is chicken as well it’s own egg.

At this point, something happens and causes organism to have more than one cell and cell specialization begins to address environmental demands. At the same time, it still needed to multiply itself.

The very first successful cell specialization necessarily needs to have both kinds of cells — egg cells and the organism cells as without the other, they will fail. Without egg cells, it will not multiply and will cease to exist.

Essentially, cells specialization as chicken and egg, would have started at the same time. Till that time, egg and chicken were one and the same thing.