A couple of Biology curricula ago, there was a small segment – one learning experience – devoted to probability. This particular lesson involved students learning the difference between the inferred ratios and observed ratios. Clearly this is an area that should allow and encourage cross-curricula study.

One trouble in modern high schools is that lessons are presented episodically and not even necessarily in anymore logical fashion than putting pieces of a jig-saw puzzle together. It takes many pieces to be put in place before the picture starts to become clear. The other issue that creates difficulty for students is the misleading use of numbers and mathematics repeated often in the media. Take for instance the recent commercial on television for a type of wiper blade sold at a major Canadian tire store. The woman proclaims that she doesn’t listen to weather reports anymore because they said there was a 30% chance of snow….and it snowed. She announces proudly, ‘they were wrong’. This commercial is repeated probably a dozen times per day or more. A student watching television would soon start to think that a 30% chance of something happening means that it won’t. Of course, this is rubbish!

There are many ways in a classroom of generating data for student analysis. For example, I have seen computer programs instantly generate the kind data that would be obtained in hundreds of generations of pea plants to simulate numbers related to Mendel’s experiments. I’m not sure that students really grasp numbers generated in such a manner. I preferred the good old fashioned coin flipping. You know, the kind where students work in pairs. Each has a coin with the alleles marked in masking tape so that a flip is like the equivalent of a meiotic division. Then when the coins land, it is the equivalent of fertilization. In this manner, the students actually experience seeing the numbers generated and appreciate the independent manner each flip is. The students can readily start to see that the observed ratios approach the inferred ratios only as the number of flips increases. This is a good time to bring into the discussion the idea that there are ways of deciding when the differences between observed and inferred is a real difference, or only one that is due to chance. It is a good opportunity to tell students that scientists don’t just look at the data and proclaim “that’s close enough!” Scientists actually have statistical methods of analysing the data. Some students will even want to give that a try themselves, especially if they have already been exposed to the methods in their mathematics class.

I recently read Leonard Mlodinow’s book “The Drunkard’s Walk: How Randomness Rules Our Lives”. I found the book a fascinating array of mathematics, history and anecdotes. I especially like the way Mlodinow presents the history. He talked about the scientists and what things inspired them to come up with their ideas. It is probably not surprising that the earliest developments in the study of probability came from gamblers and games of chance. This book gives teachers many anecdotes to illustrate probability and statistics in an understandable way.

Although the book does not mention the word gene, genome or genomics, it does discuss some of the mathematical reasoning related to DNA evidence used in court cases. Teachers will also be amused (I hope) with his analysis of student evaluations. He points out how extremely difficult it is to remain objective and come up with a reliable and valid mark for student work.


In all aspects of science education including Genomics, an ability to understand the meaning of the statistics is important. I highly recommend taking in this easy read.