One of the unique features of a biotechnology course is the opportunity to discuss bioethics and to consider how science has been used historically. While not every student will pursue a career in science, all students will be asked to make decisions related to biotechnology issues. Stem cell research, genetically modified organisms, and genetic testing are all rich topics which will have an impact on the lives of our students.
These important conversations demonstrate the relevance of biotechnology to their lives, also clarifying that the application of science is not always clear-cut. In fact, sometimes, to paraphrase Jeff Goldblum’s character in the movie “Jurassic Park,” we can be so preoccupied with if science can do something, that we fail to think about whether or not we should.
One of the topics which I find very interesting and relatable to students is genetic testing. In this unit, my students perform a lab in which they look at a portion of their own DNA – a portion which codes for whether they are a “strong taster” of a bitter chemical called PTC, a “non-taster” or a “weak taster.” (Knowing if they can taste PTC has limited utility: It is similar to a chemical found in Brussels sprouts and maybe that could be helpful information in considering meal options…) In addition to techniques such as PCR, restriction enzyme digest, and gel electrophoresis, the purpose of the lab is to show the power of genetic testing – how do we know if someone is a carrier of a recessive gene?
We start by watching some videos and reading some articles from Amy Harmon’s “The DNA Age.” This series introduces students to the reality that genetic testing carries with it serious complications. For example, one of the videos is about the genetic test for Huntington’s Disease. This test can determine with almost 100% certainty whether someone will or will not get this disease, but there are no real treatments. Another focuses on the BRCA1 and BRCA2 genes and how a genetic test for these genes can reveal an increased risk (but not certainty) for breast and ovarian cancer. In contrast to Huntington’s, mastectomy and ovariectomy are possible “treatments” even if cancer is not present. In both cases, students are presented with this question: Would you want to get tested for this disease?
We further explore this topic by looking at how genetic testing has been associated with eugenics. Students take measurements of their head circumference, arm span, and height. They then post their head circumference to height ratio and arm span to height ratio on the board. Without fail, students start to ask if their numbers are “normal.”
Next, we discuss the origin of eugenics and how it was first applied as “positive eugenics” – finding ways to encourage the “best of the best” to have kids and how who was “the best” was determined using some of the same measurements they just calculated. We also learn about “negative eugenics” – which was used to discourage certain groups from reproducing.
Of course, students are not surprised to learn that this type of eugenics was used in Nazi Germany to exterminate six million Jews. They are shocked to learn that negative eugenics was used in the United States as justification for forcible sterilization laws. These laws, which were on the books in some states through the 1970’s, resulted in the sterilization of 70,000 men and women because they were deemed to somehow be a “drain on society.” Finally, we discuss whether eugenics is still alive today in the form of pre-implantation genetic diagnosis (PGD), a type of test which allows parents to choose embryos based on a variety of genetic conditions.
This link between genetic testing eugenics and PGD is suggested in a book by Matt Ridley entitled “Genome.” I highly recommend this book. Each chapter focuses on a different aspect of the human genome and each chapter is linked to the corresponding human chromosome. For example, the chapter on eugenics and genetic testing is chapter 21 (having an extra 21st chromosome is the cause of Down Syndrome). He opens the chapter with a quote from Thomas Jefferson:
I know no safe depository of the ultimate powers of the society but the people themselves; and if we think them not enlightened enough to exercise their control with a wholesome discretion, the remedy is not to take it from them, but to inform their discretion by education.
Of course, Jefferson was talking about the importance of involving all people in a democratic government (not just educated elites), though this quote applies to the biotech classroom as well. Our students will be making decisions about whether or not to label GM foods, undergo genetic testing, or support stem cell research. They also need to understand that, even if they are not making those decisions for themselves directly, their elected representatives will be making decisions about what is lawful and what is not. They need to be exposed to the scientific facts and then allowed to draw their own conclusions.
Our bioethical discussions are rich. Students who have been fairly quiet suddenly have something to say and some stick around after class to ask follow-up questions. Whether a student remembers the details of how Polymerase Chain Reaction works or can correctly label the size marker on an agarose gel are not the most important outcomes of my time with my biotech students. Instead, I want them to have an appreciation of how these amazing advances are applied and how we need to continuously come back to the concept of “just because we can, doesn’t always mean we should.”
Until next month…