The most beautiful thing about scientific theories is that, like plants, animals, and microorganisms, they evolve. The field of genetics is rapidly evolving in response to new information that contests the long held notion that heredity comes only from natural selection operating on random genetic mutations – a theory called neo-Darwinism. A more comprehensive theory is taking the stage which includes the genome’s remarkable inheritable regulation – a phenomenon known as epigenetics – creating a new theory called progressive Darwinism. This renewed focus on the mechanism of evolution brings back philosophical questions about the importance of evolutionary theories in the face of things such as altruism.
Darwin gave us the theory of natural selection – “survival of the fittest” – which proposes that individuals who are more adapted to their environment survive better, reproduce more often, and are able to influence the development of their species. Darwin’s ground-breaking theory is driven by several things: the variation between individuals, environmental stress, and how variations help or hinder individuals in the face of these environmental stresses. DNA can be thought of as a series of chemical letters – A, C, T, and G – and is divided into hereditary units called genes. Every gene contains information required to make proteins and functional RNA chains. Even changing a single A to a G can result in a dramatically different protein. These changes occur all the time, and are the cause of variation within a population. The environment places stresses on the individuals of a population. Some of these individuals, by random chance, have an edge – one that is given to them by these variations in gene mutations. These individuals survive and reproduce more than those who don’t have the same mutations. Over time, mutations can accumulate, and different environmental processes can operate, and, ultimately, if changes are significant enough, an entirely new species can be created, each suited to the environment it was “forced” to conform to.
Neo-Darwinism is convincing from a purely logical standpoint. If an individual is better suited to its environment, it will necessarily be more likely to survive and reproduce and its genes, will necessarily be more likely to survive the test of time. Where neo-Darwinism falters, though, is in its simplicity. Take the human genome: we only have about 25,000 protein-coding genes – and we share large percentages of these genes with things like bananas and lettuce. Our DNA is about 99 per cent the same as a chimps. Where does that “human spark” come from, then? The answer hypothesized by some scientists is called progressive Darwinism, which is still a gene-centric view of evolution, but one with a significantly refined view of heredity.
Not all genes are equal; they don’t just produce proteins at the same rate all the time in all cells. That is to say, they can be switched on and off. This is why your muscle and liver cells are different – they have identical genomes, but have different genes switched on, which leads to their specific functions and shapes. The genome can respond to changes in the environment, to chemical messages from other cells, and to other regions of DNA – once thought to have no function and called junk DNA – now known to be regulatory regions. The regulation of gene switching is very complex, with different environmental signals, regulatory regions, and chemical messages cooperating and competing to determine what proteins the cells will produce, and, therefore, what its functions will be. So in addition to a unique genome, we each have a unique epigene, a pattern that dictates which genes are active and which are inhibited.
Recent studies show that the epigene can be transferred from parent to child, imbuing the child with the epigenetic patterns that the parent has acquired through a lifetime of environmental adaptation. This is essentially a method of “genetic learning”, a fine-tuning of the genome that creates a “memory” of the environment that is passed down. For example, an animal living in a hot desert that has plenty of bugs to eat but very little water would switch on genes that helped it store water at high energy cost (with the extra energy needed provided by the abundance of food). Put the same animal in a place with plenty of water and it would shut off the costly water storage gene. But the epigene can only do so much with the genes that are present in the individual. If that same animal were put in a cold environment, it might freeze to death.
The epigene plays an especially prominent role in development, and explains why we don’t look like chimps – though we may have largely the same set of genes. For example, the genes that code for, say, the jaw, are turned on for longer in chimp fetuses than in human fetuses, which is why chimps have strong, large jaws and we have more brain room instead.
Ultimately, the epigene can be thought of as the brain of our genome. This brain is one that is set on its own survival, which begs the question: is there really a place for altruism in what is still ultimately a selfish gene model?
In reality a more accurate term might be the indifferent gene. Without actually wanting anything, genes are thrown into an equally indifferent environment, and a simple game of cause and effect develops – the environment acted like a sieve – the genes that survive are able to live on. When cells are able to bind together into multicellular organisms, differentiation is possible. With the creation of different types of cells, an organism is more likely to survive. It is not hard to see how this trend could lead to a highly developed nervous system – the functioning of which neuroscientists believe constitutes thought. The nervous system – which determines behavior together with the genome and its epigene – which determine the nervous system’s structure and function – could have evolved the capacity for behaviors like altruism. Altruism makes evolutionary sense on a larger scale than that of an individual and its genes. Cooperation can ensure that the genes of the community will survive. Even if I help someone at my own expense, that might help them or the community survive, and, as long as the genes common to all of us survive, it does not actually matter which one of us passes them down.
What about the fact that we feel good when we help others? It may be as simple as the reason why sex is pleasurable – by creating a rewarding feeling, the genome has developed a clever way to guide us towards the things that ensure its survival. In this way, all goodness can be said to be based on greed.
Although there is a notion of transcending the basic greed that, by evolutionary necessity, motivates all aspects of our existence it is hard to determine if these efforts are successful. This raises many philosophical questions, such as whether actions alone can be grounds for being good, despite whatever selfish motivations may be there – consciously, subconsciously, or hidden deep within our genome. While this question will puzzle us for ages to come, a good place to start would be the analysis of the singular human ability for reflection and abstract thought. Since we are able to attempt an understanding of evolution, we are in the unique position of being, possibly, the only species which can deliberately guide its own development. This knowledge may turn the tides of the hidden and subtle battle of sorts between our own consciousness and the epigene. Perhaps the epigene will be overthrown by its own creation: the human consciousness.