The Selfish Gene is a landmark 1976 work in the field of biology: It puts the gene at the center of the process of evolution and explains how, when this is taken into account, genes must be seen as “selfish.” Author Richard Dawkins then uses this theory of gene selfishness to explain the massive variety of animal behavior observable on Earth.
Over 3.5 billion years ago, in a primordial soup of molecules, the first, simplest form of life on earth came to be: a molecule able to copy itself, a replicator.
Molecular replicators are made up of long chains of smaller building-block molecules in the same way that a word is made up of a string of letters. Replicators copy themselves by attracting other ‘letters’ and acting as a template for them to match up to.
The first replicator automatically had a competitive advantage over all the other molecules in the primordial soup because they could not copy themselves, and hence the replicator became more numerous than any other type of molecule.
However, mistakes in the copying process led to ‘daughter’ replicators that had a slightly different configuration than their ‘parent.’ These new configurations meant that some ‘daughters’ were able to copy themselves faster, or more accurately, giving them a competitive advantage over their ‘parent.’
More and more replicators were built from the finite supply of building-block molecules in the primordial soup, and these molecules were gradually used up.
These two concepts – a population in which ability varies and an environment of limited resources – are the basic requirements for the process we know as evolution.
As time went on, further mistakes in copying resulted in new advantageous characteristics, such as the capacity to break down other replicators and use their building blocks for replication: the first carnivores. Through the creation of new variations, and the survival of the replicators with the most useful advantages, more complex life forms emerged, eventually resulting in the variety of organisms we see today.
Evolution is driven by varying abilities and limited resources.