Bridgette Byrd O’Connor, BHP Team
Louisiana, USA

Students ask questions… they ask a lot of questions! Answering them or guiding students to find those answers is part of our job as teachers. Many BHP student questions have to do with the key point in the driving question for driving question (DQ) for Unit 5: How and why do theories evolve? In particular, many students have questions about the scientific theory of evolution. A short aside with a little background: I taught for 10 years at an all-girls, Catholic high school in suburban Louisiana. While the Catholic Church’s views on evolution have changed over the years, and it now accepts this scientific theory and the evidence behind it, some parents, and therefore, some children, have not. I have heard similar circumstances from numerous teachers in various locations across the United States. Many teachers have posted to the online BHP community to ask for strategies about how to answer these parental and student concerns about the theory of evolution, as well as the Big Bang theory. In many ways, both the answer to the Unit 5 DQ and the assets for this unit help to provide guidance for addressing these questions and concerns.

Theories evolve when new questions are asked about a topic and new evidence is found. With regard to evolution, Darwin (among others) asked new questions about the variety of species on Earth and evidence was found that answered those questions. For decades thereafter, scholars from multiple disciplines found evidence to support the scientific theory of evolution. As this evidence was published and disseminated, it was tested by hundreds (if not thousands) of scholars. As a result, the theory developed and become accepted by other experts. I believe that this is how the Unit 5 DQ should be answered and how teachers might answer questions from those parents and students who are uncomfortable with the scientific theory of evolution (as well as the Big Bang). These theories represent the best scientific evidence that we currently have, and as teachers, our job is to inform students about this evidence.

There are many Unit 5 assets that will help students understand how to answer the DQ, but there are a few that are my favorites because of their positive effect on student engagement and understanding. The first of these is How Closely Are We Related? This activity is a fun way to start the unit and get students thinking about our (human) relationships with other species. The animated David Christian video, Mini-Thresholds of Life and the accompanying activity, which asks students if these are the right mini-thresholds, certainly engage students (cartoons are always fun!) and help them understand the relationships between species and how evolution works. In addition, the Crash Course videos in this unit help to engage students and aid in their understanding of the theory of evolution and the evidence on this subject. Another topic that relates to how and why theories evolve is presented in the Walter Alvarez video, How We Proved an Asteroid Wiped Out the Dinosaurs. Professor Alvarez explains how new questions were asked about this topic and new evidence was gathered that helped answer them. As a result, new theories emerged that were tested and then generally accepted by the scientific community. All of these will help lead students to the answer to the Unit 5 DQ.

About the author: Bridgette Byrd O’Connor holds a DPhil in history from the University of Oxford and has taught Big History, world history, and AP US government and politics for the past 10 years at the high school level. In addition, she has been a freelance writer and editor for the Big History Project and the Crash Course World History and US History curricula.

Header image: From left to right: 1) Ape skeletons, public domain. 2) Charles Darwin’s 1837 sketch, his first diagram of an evolutionary tree from his First Notebook on Transmutation of Species (1837). Public domain. 3) Darwin’s finches or Galapagos finches. Darwin, 1845. Public domain. 4) Photograph of Charles Darwin; the frontispiece of Francis Darwin‘s The Life and Letters of Charles Darwin (1887). Public domain.

One thought on “How and Why Do Theories Evolve?

  1. Distinguishing between “idea” and “theory” is useful for young learners, since they see these words often, even seeing these terms applied incorrectly. It is easier to share ideas, more difficult to advance theories. We are unfortunately drawn to ease; we should resist ease and embrace more difficult endeavors, for it is in the challenge that we experience growth and learning.


Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s