Why We Should Teach Evolution Earlier in Biology Classes
I was recently presented with the chance to redesign an online introductory biology class. The was a very exciting opportunity for me! I started by thinking about what I wanted the students to take away from the class. I also wanted an overarching theme the students could refer back to and place the information from each chapter within a broader picture. What theme would do that? Well that answer came easily. Evolution! As Dobzhansky said, "Nothing in biology makes sense except in the light of evolution."
Great, I had a theme. I went back to my textbook and realized that evolution wasn't taught until chapter 13! That was well over half way through my class. Sure it was mentioned in the introductory chapter. It was briefly mentioned as a side note here and there in other chapters, but it was not used as a means to connect topics together in the early chapters on cells. A lot of the facts surrounding cellular evolution are still unknown, but based on what we know about evolution of populations and species couldn't we speculate in these chapters so students could have an educated guess about how and why cells have evolved to have the organelles they do?
Adult Learners Need More Context
Right now these cellular chapters are full of a lot of facts about how things work together. Answering the whys and hows of where cells and their organelles came from would give students new to biology more context to help them place and retain the information in their own knowledge base.
It has been argued that we don't need evolution to make sense of certain biology topics. Presenting cellular biology to a student without answering the how and why questions though leaves much to be desired for an introductory education. Including some speculation on the hows and whys will allow the students to take their thinking about biology to a higher level. They will be able to start asking how and why questions and speculating on answers themselves. Socially constructing biology facts by discussing these questions with others.
This need to integrate evolution into earlier chapters of introductory biology textbooks is directly related to the principles of andragogy established by Knowles for adults learners. In particular, once a new concept is established adults want to use it for problem solving. If we are discussing cellular organelles, students can understand what the nucleus does and why it is important, but how and why did it come to be there? That is critical information to help them evaluate biological systems and relate them to other systems they know.
Evolution Can Inspire Creativity
Bloom’s taxonomy is used to help design activities that require students to use higher order thinking skills, such as creating something new, to encourage retention of the information. Below is a table that shows some biology activities that were designed to meet the highest level of thinking in Bloom’s revised taxonomy with and without evolution integrated into the project. The activities that integrate evolution into the project increase the depth of exploration by the student into the subject.
Class activities without evolution
Class activities with evolution
Create a cell and describe how leaving out an organelle would impact cellular functions.
Create a cell with primitive organelles and describe how evolution will act to transform this cell and its organelles into a modern cell.
Design a user's manual for a plant or animal cell. Include descriptions of all pertinent structures and functions.
Design a user's manual for a plant or animal cell. Include information on how structures/functions of the cell will allow the cell to evolve and why evolution is important.
Create a sales pamphlet of organelles from eukaryotic and prokaryotic cells.
Create a sales pamphlet of organelles from eukaryotic and prokaryotic cells aimed at selling the organelles to a primitive cell who wants to evolve into a modern cell.
Redesign the process of passing genetic information in DNA to the phenotype. Use or modify any cellular components to improve functioning and write a paper about how your new cell functions better than current cells. If you do not choose to make improvements write a paper describing why you didn't make any changes.
Redesign the process of passing genetic information in DNA to the phenotype. Use or modify any cellular components to improve functioning and write a paper about how your new cell functions better than current cells and speculate on why evolution has not produced the changes you imposed. If you do not choose to make improvements write a paper describing why you didn't make changes and how evolution impacts you decision.
Including more ways students are able to explore a topic increases their ability to be creative with their final product, and they will be able to recognize connections with other topics. Fostering a passion for biology, and other STEM subjects, requires the ability for students to see the connections between topics themselves and then transfer that knowledge to new topics. The more connections they can make themselves the stronger their internal motivation to continue in the field will become, another important part of andragogy mentioned by Knowles. More moments when they go, “OH! I get it!” may be all we need to help retain STEM students. In biology, I think integrating evolution into the curriculum earlier will make a big difference!