Welcome to a new feature on my blog: The Science of Science Fiction. Whenever I find interesting science articles online, I intend to link to them and discuss both the science and its potential in science fiction. My first article comes from Time and is titled "Why Genes Aren't Destiny."
As you probably learned in high school biology, deoxyribonucleic acid, better known as DNA, is the carrier of our genetic information. (For a refresher course on DNA, please check here and here.) With the exception of red blood cells and eggs/sperm, all cells in the human body carry all of the instructions, or genes, needed to create a human being. However, not all genes are needed in all cells, and even the ones that are on in a given cell have to be regulated. In order to turn genes on or off or to change how often their instruction are read, small molecules bind to DNA in specific places. These chemical markers form the basis of epigenetics, the study of non-genetic changes in genetic regulation that are heritable.
These changes in gene regulation can persist for a surprisingly long time. The article in Time discusses a Swedish study linking overeating as a child, even for a single season, to significantly shorter lives for that child's grandchildren. (That's a very scary thought, given the typical American diet!) Fortunately, unlike changes in the DNA sequence, the markers aren't permanent and can fade if the environment changes. Also, these markers are a possible target for new drugs to treat certain illnesses. Some markers can even overrule poor genes. Pregnant women are urged to get extra folic acid during pregnancy. It turns out that folic acid is a source of markers called methyl groups (one carbon and three hydrogen atoms), and a study in mice showed that giving folic acid to pregnant mice with a genetic tendency toward diabetes resulted in the babies turning out healthy.
So, what does all of this mean for a science fiction writer? Epigenetics is still a very new field, with much to be learned. One thing that is known, however, is that some genes have different effects depending on if they came from the father or the mother; this is another example of DNA markers at work. As a science fiction writer, I could see using epigenetics as a way to explain differences between genders or as a way for a population to change very quickly in response to their environment. You could even create a single alien race with several distinct types of individuals; they could all have the same genes that are regulated differently based on the genetic markers they bear.
I hope you found this new feature of my blog interesting and not too overwhelming. If you have questions or comments, please feel free to post them. Like our genome, this blog is also open to evolution!