Cancer’s convergent evolution

Cancer is an evolutionary disease

The concept of evolution is very useful as it applies to cancer, because it forms a paradigm of understanding that simple genetics cannot match. Charles Darwin, studying animals in the idyllic Galapagos island formulated the theory of evolution by natural selection, which was revolutionary at the time he published it in his book On the Origin of Species (1859). According to legend, he had noticed that the shape and size of the beak of a finch varied according to the food source.

For example, long, pointy beaks were great for eating fruit, whereas the shorter thicker beaks were good for eating seeds off the ground. He reasoned that this could not simply be a coincidence. Instead, he postulated that there was a process of natural selection going on here.

Just as with humans, there are those who are shorter or taller, muscular or lean, fatter or thinner, blue or brown eyes. Within a population of birds, there are those with longer and shorter beaks, and thinner and thicker beaks. If the main food source is fruit, then those with longer pointier beaks had a survival advantage and would reproduce more often. Over time, most of the birds would have long pointy beaks. The opposite happens if the main food source is seeds. In humans, we see that people in northern Europe tend to have very fair…