Biology Question

Question

Genetic mutation is what leads to the mechanism of natural selection, and thus contributes directly to evolution, a necessary and useful process. The crossing over and randomization at fertilization also increases variation. Without the variation that results from mutations, natural selection would not occur, thus proving that genetic mutations are beneficial and crucial for life. However, cancer is a disease caused by mutation. Does this mean that cancer is inescapable for all humans if we simply live long enough?

Answer 1

Hello Jen!

That is a pretty good question.

There are loads of factors that have been studied to play a role in the development of cancer. However, just because something has a role in development, does not mean it will always cause cancer. For example, smoking is often correlated with the development of lung or throat cancer. The physical mechanism (the way in which cells become cancerouus) is not entirely understood.

Another example can be the consumption of plastic. Some studies have made very weak correlations to the amount of food eaten from plastic containers and the development of colon cancer. Because this correlation is very weak, it could be assumed that eating food out of plastic containers is not that much of a contributer to the development of cancer.

Another interesting example is sun exposure. People who live in very sunny areas run the risk of being exposed to UV rays a decent amount of time. There is a correlation between individuals who have been in the sun a lot and the development of a type of skin cancer called melanoma.

So, even if we did not have genetic mutations that predisposed us to development of certain cancers, interacting with our environment can sometimes cause our cells to become cancerous through various mechanisms or pathways.

But, let's assume our environment has nothing to do with it, and we live for a very long time (more than 100 years) we would indeed develop some form of cancer due to the replication of cells in our body. As cells replicate, we have an increase in error in our DNA. With each error, we have an increase in chances of that cell becoming cancerous.

Let me know if this answer is confusing in any way.

-Jose