17 September 2012

What is a replicator?

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What is a replicator ?
The best definition of a replicator that I have come across was given by Richard Dawkins in his book, The Selfish Gene, and it goes like this :
  • A replicator may be defined as any entity in the universe of which copies are made.

What is not a replicator?

To better understand what it means, let’s see what a replicator is not. A replicator is not something that is being created independently over and over, for example, the molecules of CO2 that every breathing person creates are not copies of one another. Although they are identical, they are not created through a copying process which would involve an original CO2 molecule being copied.
According to the definition, photocopying texts or images would turn those texts and images into potential replicators. So, it seems, could be said of the photocopier itself, of which copies exist in numerous offices. The same goes for music and sounds, and the same goes for food and drinks too. What can be said of ideas ? Those ideas that we pass on from one person to another and of which our culture is made. They do seem to be copied as well. But how, what is an idea, and what does it mean to copy it ? These are some of the questions which memetics need to answer to.
What we can say for sure is that a replicator is something that happens to be copied faithfully over and over because of the way it interacts with its environment.
Sometimes though, it is not easy to see what it is that is being copied. The path that the copy takes to being generated may or may not be complex; it may take plenty or little time, plenty or little energy. In real life, replicators can go through very twisted paths to manage copies of themselves and take decades to do so whilst consuming vast amounts of energy. Although the definition given by Richard is simple and very true, it can be difficult to pinpoint what is actually being copied and much debate ensues over this question. This results in a lot of uncertainties with regard to the meme theory. We will come back to these questions later.

Examples of replicators.

There are only two known types of replicators on this planet: the genes and, if one accepts their existence, the memes. Genes, are very well understood and can be described as specific chains of nucleotides being copied and passed on from generation to generation via sexual reproduction. With regard to memes, a good example of meme is the letter A or a computer virus or even the Christian cross. All get faithfully copied over and over inside human culture. Susan Blackmore would describe the process of cultural copying as "imitation". We will come back to Susan's concept of imitation on a later stage.
Both genes and memes seem to correspond perfectly to the definition of the replicator. This said meme’s copying fidelity might be low in some types of environments meaning that some of them barely meet the requirements to be replicators. However nowadays memes are getting better and better at being copied thanks to modern technology. These aspects are very important in defining memes. They will be explored in later chapters.


What we have here with this definition is a very logic model of the replicator which makes Richard Dawkins’ definition a true algorithm. The beauty of this algorithm is that it is very simple and yet very powerful because the emergence of life as we know it depends on it. However, to agree on the significance of this definition, we need to agree on what is meant by “entity”, “universe” and “copy” and although these may seem straightforward we will see later on that it is not as simple as it seems.