Interpreting Phylogeny: Journey to Flight

Let me start the New Year with a confession: I hate interpreting phylogeny in informal science. You would too if you had experienced all my spectacular failures. I’ve tried morphological observation of extant taxa, only for participants to become fixated on “skull color” or the fact that a taphonomically damaged skull lacks front teeth. I’ve experienced conversations using the metaphor of family trees turn into frank discussions about divorce. Sometimes the conversation veers so wildly off the rails that I just skip phylogeny and go straight for function, because at least sagittal crests and canine sexual dimorphism are fun and interactive.

Understanding phylogenetic relationships is foundational to resolving misconceptions in evolution.

Don’t get me wrong. Understanding phylogenetic relationships is foundational to resolving misconceptions in evolution. Trees avoid the problem of a linear characterization of evolution, branches allow visualizing branching events as points within a decision tree, and true phylogenies (e.g., those without time) allow for relational placement of fossils. Teaching phylogeny effectively is crucial if we want to reach the large percentage of the population that is curious about evolution but needs more scaffolding to feel comfortable rejecting creationist rhetoric.

Unfortunately, evolution is messy. Sometimes speciation points happen without a corresponding character, sometimes there is an irreconcilable amount of homoplasy, and sometimes a beautiful morphological phylogeny can be rendered completely inaccurate by phylogenetics. The classic example typically used, like whales or horses, are not only problematically linear but happen very rarely in nature. Is it appropriate to teach an idealized version of evolution if there are far more exceptions than rules?

Evolution is even messier in the realm of informal science education. First, we must provide appropriate content to the diverse range of ages and abilities present at an average outreach event. Then, in order to lower the barrier to engage with science, we have to help empower people to find the answers for themselves. When phylogeny activities set participants up to fail, they reinforce the “us versus them” notion that can discourage people to pursue science. Finally, despite the importance of phylogeny, it is ultimately a topic that few people find interesting in and of itself. Conversations about phylogeny that are unmoored from an interesting question about evolution are likely to result in short attention spans and very little effective learning.

Journey to Flight kit components

Photo by Emma Doctors

Based on all these factors, I’ve been hesitant to develop a new phylogeny activity. We decided to retire our current phylogeny activity, “Turtle Time,” because of many of the issues discussed above. While it was a huge hit among many of our fellows and group leaders, we worried that it was encouraging lectures and not allowing participants to find the answer for themselves. To reinvent the activity, my colleagues Emma Doctors, Anna Ginther, and I spent a long time researching best teaching practices for understanding phylogeny, seeking a suitable evolutionary story that reflected many of the nuances of evolutionary analysis without setting up our visitors for failure. Despite being one of our simplest kits in materials cost, it has taken more than eight months to develop our January 2020 activity, Journey to Flight.

Journey to Flight is in many ways a traditional phylogeny activity that explores how flight separately evolved in bats, pterosaurs, and birds. However, we’re excited about the ways that we have developed solutions for some of the most common problems in presenting evolution. We place homoplasy at the center of an engaging evolutionary story, but help scaffold the participants' understanding of the important traits so they are better equipped to understand the nuances. We also use fossils and extant taxa together (rather than using fossils on interior nodes), allowing participants to understand that most techniques to resolve relationships of extant taxa also work for fossils. We developed two sets of traits, one that includes conflicting information and DNA and one that quickly resolves the phylogeny. We allow the activity to be flexible for different audiences, even at the same time. Most importantly, we model the process by which phylogenies are created and evaluated, achieving the all-important goal of demystifying evolution.

While I still may not like interpreting phylogeny as a topic in informal science education, I think this activity has the most positive participant response of any phylogenetic activity I’ve participated in developing.

This activity serves an even broader purpose, however. Through this activity, we want to further our understanding of how people learn about phylogeny, especially in our target underserved populations. Therefore, we are continuing a multi-site research project using Journey to Flight to understand how to erase misconceptions around a complicated phylogenetic topic. We are explaining phylogeny in three different ways, then evaluating what percent of participants get the challenge question correct. If you are part of an outreach site and are interested in getting involved, please e-mail Emma Doctors. Hopefully we can work together to make understanding phylogeny a less painful concept across informal science.

If you like Journey to Flight, browse all our DIYSci kits.

Kate Carter
Short Bio

Kate Carter is Director of Community Science Education at NCSE.