Course: Genetics: The Fundamentals
Length: 6 weeks, 4-7 hrs/wk
Instructors: Michael Hemann, Peter Reddien
How do we know what we know about heredity and how can we design experiments to test hypotheses in genetics? How do we study the inheritance of different traits? How does that information help us understand heritable diseases? …You will explore the foundations of the field of genetics and how to apply those concepts to understand modern studies of heredity.
I’ve noticed, more and more lately, a Conflict of Interests statement preceding academic research papers. Well, here’s my Conflict of Interest statement for this post: I don’t like genetics. While I’ll spend hours poring over biochemical pathways and G-protein coupled receptors and T-cells vs B-cells and the twists and turns of central dogma of DNA to RNA to protein, I just don’t care about the probability of offspring bearing recessive traits should a recessive phenotype and a dominant phenotype mate. I care even less about gene mapping, which isn’t to say I don’t appreciate its importance, just that I don’t particularly want to get into the nuts and bolts. Conflict of interest stated.
I do, however, feel like some idea of the basics is necessary, given my interest in other areas of biology. So when I saw a tweet declaring this initial-run of the first of three moocs in a series on genetics, I clicked. And in spite of my misgivings, I’ll admit: it was very useful in getting a firmer grasp on the basics, which is, after all, the point.
The course starts off with a solid review of basic concepts and definitions: genes and chromosomes, phenotypes and genotypes, recessive and dominant traits, and complementation. There’s also an optional section reviewing meiosis. From there it moves into Mendelian genetics, inheritance patterns, and pedigrees. The later sections involve mapping strategies using SSRs and SNPs and calculating genetic and physical distances to determine linkages. Some math is involved in the form of Chi square tests, Bayes theorem, and LOD scores. It’s all straightforward basic algebra, with the tricky part, as is usually the case, being knowing what data fits into which variable.
One interesting aside: in the section on pedigrees, which are graphic representations of inheritance showing male and female matings and offspring, some new symbols were included to indicate nonbinary and trans people. Obviously, the crucial info in a pedigree is who contributed the egg and who the sperm, so birth gender and biological sex was of primary significance, but it’s nice to see the effort towards inclusion. I hope this doesn’t get them banned in some states.
The overall structure of the course is similar to other MITx bio moocs: two or three lectures per unit, divided into short (usually <10 minutes) segments followed by graded Knowledge Check questions that allow unlimited attempts (meaning they’re basically free points); and four more stringently graded Quizzes, the fourth of which is paywalled ($99) for those purchasing Certificates.
The lectures will perhaps one day be classified as COVID-era by cyberarchaeologists: one set was delivered online with a zoom or chat function so remote students could ask questions (these are recorded, so this function wasn’t live in the mooc), and another set was live-in-classroom with a Masked Professor. While there were some well-produced graphics, particularly in the SSR and SNP sections, what was missing were those wonderful animated inset videos MITx has always been so good at, explaining specific topics in detail for those of us who don’t have recitation sections. I could have used a few of those for the mapping segments; I found the lectures covering LOD scores difficult to follow and I had trouble figuring out the actual approach being taught. Oddly, I also had a terrible time with gene notation: X^D X^d being represented in several ways to indicate an affected gene and a wild-type gene as dominant and recessive. Some pretty pictures might have helped a bit, though I eventually got it – and this is, after all, listed as an advanced course, so maybe they assume if you need pretty pictures, you shouldn’t be here.
I found the discussion forums very helpful on several occasions, with both staff and other students answering questions promptly and clearly.
The quizzes were where I actually did most of my learning. I’d go back and figure out what in which lecture was pertinent. I didn’t always get it right, but I understood the material much better afterwards. This made the quizzes functionally more of a formative rather than summative assessment. Unlike other MITx bio moocs, there were no assays (beyond performing crosses) so the quizzes were much closer to the Knowledge Check questions. I still could have used a middle level in there, a practice quiz before the real quiz, so to speak. But I did figure most of it out, and that is the point.
It’s interesting that the quizzes allowed access to correct answers immediately on completion rather than at the end of the quiz – or, in the case of some of the instructor-scheduled moocs, after the quiz period closed, which sometimes meant waiting two weeks to find out what you did wrong. This worked a lot better for me, in that, if you get the setup wrong and can’t figure out what the problem was, chances are everything following is going to be wrong. I don’t know if this was a pedagogical decision to provide immediate feedback, or an administrative decision to improve completion percentages, in light of the recent edX move from non-profit to profit-making organization – or, for that matter, a random decision in the time of COVID. Of course, those with more discipline can simply choose to not click on Show Answer. I confess to a complete lack of such discipline.
Despite my insistence that I do not like genetics, it was Duke’s Genetics and Evolution mooc back in 2015 that was my first foray into biology. It was a blast, partly because some mooc friends were CTAs and there was a great deal of camaraderie back in the day when camaraderie was possible in moocs. I’ve been doing bio ever since, though I have to admit, as many times as I’ve gone through Eric Lander’s terrific Intro to Bio course to refresh my memory on assays or whatnot, I’ve always skipped over the genetics section because, say it with me, I don’t care about genetics… too bad, since he’s a world-class geneticist, but that’s how it goes. Still, I’ve taken at least one run-through of all of MITx’s biology moocs – except the computational biology workshop, which scares me – and it all started with genetics.
I asked, as I finished the course, what parts 2 and 3 would cover:
We are still developing the next courses, so I cannot promise what they will entail. However, they will likely include methods and techniques to study and edit the genome (think genetic screens, mutant design, CRISPR, knockouts, etc.) as well as some applications such as gene regulation, development, and behavior. We are also hoping to develop material about population genetics.
Maybe I’ll face that as well, because as it turns out, genetics isn’t so bad after all.