Teaching the Genetics of Height and its Implications

Teaching the Genetics of Height and its Implications

This week Yetunde and I stayed with the area of genetics. We chose this article https://www.sciencedaily.com/releases/2017/02/170201131513.htm from the website Science Daily.  We chose this article as it is cutting edge and can be used to serve as a template for future studies of polygenic traits. The topic of height is also likely to be at the forefront of the minds of many of our students and will therefore have added relevance. We decided to stay with genetics for a number of reasons. It is a large part of the Biology course. We can show our students that Biology is always learning and changing, and I have found that students are fascinated by the power and influence of genetics.

I was immediately interested by the article. I have always liked to know facts and dimensions and always wanted to be tall. That I am a centimeter taller than anyone else in my family is still a source of some (childish) pride! Any reflection on height should tell you it is not pure Mendelian genetics with an either or outcome. The height trait is a spectrum of possibility being influenced by many factors. The vocabulary throughout gave good opportunities for revision of genetics and some cross curricular thoughts, as well as insight into how biologist think and go about their work.

The main idea in the chapter is that there can be many factors in a single trait such as height. This is important to teach the students especially if you have spent time on Mendelian genetics with its valid but simplified outcomes. Students have a tendency to think in these simplified paradigms and often the questions they ask about rare or maybe fabricated traits they see on the internet would require a more complex view of genetics with a greater appreciation of the myriad of possibilities. I also like to stress that we know some areas quite well but Biology is constantly learning and even finding questions we did not know we had to ask! Teachers should also stress the points made in the article about how scientists work. The article alludes to large scale research tests done with worldwide collaboration, and then the results are checked for validity. We can let our students know that we encourage these practices in class because they are the basis of much professional work too.

There is some talk of Mathematics in this article and it would be good for the students have knowledge of Algebra, units and their conversions, and statistics. As a teacher I would use this opportunity to show this as an example of where Math may be used outside of school and to test the students a little bit on their Math. Math and Science are inextricably linked and that point should be made explicitly and often.  The students should also have a good understanding of basic Genetics in order to process the overall message of the piece. The overall point that genetics is very diverse and complex is sure to stretch those who reflect upon that idea, but at least the article is not complicated by differing viewpoints or conflicting sides. The message that this is new research with possible implications in work on other similar traits is strong throughout.      

There are many points throughout that I would focus on. In Genetics terms, there is mention of frequency and variation, the connection to proteins and skeletal growth. It is important to stress these points to make the students think on DNA and it’s effects in these terms. I find students still think about DNA in an isolated sense and do not give the molecule its due. The article gives a good example of polygenics and this is worth having a class discussion on too. It is not often that you can isolate one gene that does one specific function. More commonly there are a myriad of genes involved which may block or enhance others, work together, blend or mix together or may not be expressed. All of which gives rise to the differences we see in everyone and ever living things we may see. The Math also comes into this point. We can only work on probabilities of things occurring until we actually see them in an individual and then we can only predict the next generation too. The article also gives a tantalizing glimpse into the future. Having isolated the protein STC2 and seeing its influence on height we may, in time, be able to create a treatment for short stature. This could be put to the students as an essential question from this piece. How far reaching could this study and studies that stem from it be? What are its implications and where could we go from here?

The students would certainly need to be comfortable with language such as genome, carrier, variant and markers, before reading the article but I like that the complexity comes more from the overall concept that from the contained language. This can be used to show the students that there is underlying simplicity but in piecing together the vast amounts of moving parts in genetics you get the complexity we encounter in living things. This discussion could then be used to introduce a unit on Mutation.

I feel the article best displays the text frames of cause/effect and problem/solution. It is cause and effect due to the author explaining how genetics of height works and how science explains it (Buehl, 2014). The problem/solution section is alluded to when it is mentioned that identifying proteins and therefore the genes which cause these undesirable traits we could work towards methods of changing them (Buehl, 2014). The article also mentions using the work done here as a blueprint for other such studies.    

I think article is written for students or those with an interest in biology, genetics and medicine. While the article is short it does give interesting insight into what we are currently working on and how it is being done. It also poses interesting questions for those who will reflect on the article. What is the next step? Where can the results of this study bring us to? What should we do with new knowledge coming from this study?

Yetunde asked me to think about using Stop and Think Prompt cards. This strategy involves getting the students to use broad open questions to ask each other about the text that has just been read. Questions such as
1. What is the author’s purpose with this piece. Give evidence for your answer from the text?
2. How does this article relate to what we have learned already in this unit?
3. What comprehension strategies did you use when reading this article?
4. What is the Big idea or Essential Questions of this article. Support your answer with evidence form the text?
5. What questions would you ask the author?
I think this strategy and these questions would work very well. They would challenge the students to think and reflect on the material. They ask for what the students thinks about article and author’s purpose not just what is written down. The students will have to assimilate the material and make inferences about the meaning and what is implied or even what is not said. The students would be forced to mull over the text, the meanings in the text and the author’s thoughts before generating their own thoughts. Then they would have to back up their ideas with textual evidence. These are very important skills both for disciplinary literacy and for 21^st century education (McLaughlin, 2015)(Bellanca & Brandt, 2010). I think it would be very valuable to show the students just how long a conversation or a sharing of ideas can be generated from quite a short text. It would be helpful to show them what we are trying to get them to think about when we approach literacy.

(Just to note, Yetunde’s strategy came from an Irish source so it is, of course, Superior!)

Thanks

References

McLaughlin, M. (2015). Content Area Reading: Teaching and Learning for College and Career Readiness.    

                Boston, MA: Pearson

Bellanca, J. & Brandt, R. (2010). 21^st Century Skills; Rethinking How Students Learn. Solution       

Tree Press

Buehl, D. (2014). Classroom Strategies for Interactive Learning (4^th Ed.). International Reading

                Association