Making Sense of Evolution

2016 Volume VI

Introduction

Earth is a dynamic planet, where change is perhaps the only constant in its roughly 4.5 billion-year history. This constant flux is seen in natural climate and environmental changes, as well as human activities that radically alter Earth’s ecosystems. Life on Earth is also in constant flux, and evolution is the process by which organisms genetically change to keep pace with these ongoing challenges. The confusion (and controversy) over evolution concerns the study of species relatedness in the deep past, particularly the shared ancestry of humans and the rest of Earth’s teeming biodiversity. But it is vital to understand that evolution is an active and continual process, which affects all current-day species including humans. Many examples come from human medicine, such as the global problem of evolved drug-resistance in bacteria, and the recognition that cancer spread in the body is essentially an evolutionary process. The mass production of food has clear societal benefits, but modern agriculture uses genetically similar organisms that are vulnerable to pathogens and pests that evolve to exploit them, causing huge economic losses. The understanding of evolution has transformed a wide variety of fields, ranging from forensics to linguistics, and conservation biology to software design. Also, technological innovation relies on evolution thinking, such as engineering design principles of airplanes, submarines and other machinery that mimic evolved forms in nature. Evolution especially impacts biotechnology, such as using directed evolution to manufacture algal biofuels and other alternative energy sources, and informing synthetic biology approaches to construct novel biological parts, devices and systems.

The seminar “Making Sense of Evolution” explored the fascinating importance of evolutionary biology in our dynamic world, and was designed to appeal to biology/science teachers at all grade levels. The overarching goal was to empower teachers in their knowledge of the often-confusing topic of evolutionary biology, with the expectation that this understanding would enrich the classroom experiences of their students. The resulting units were diverse, reflecting the varied interests and backgrounds of the Fellows. Jennifer Claudio develops a unit for high school students concerning the evolution of species diversity in insects and other arthropods, emphasizing how the differing feeding habits and other unique adaptations of these “silent witnesses” help forensic scientists pinpoint details such as time of death in crime scene investigations. The focus of Akemi Hamai’s unit for eighth graders is on the bioethics of genetic engineering, and weighs the benefits of our ability to harness naturally evolved mechanisms such as CRISPRs to genetically alter organisms, eradicate mosquitoes and design babies versus the costs of using such technology that may accidentally alter biological systems in unexpected and uncontrollable ways. David Ostheimer’s unit for first and second graders helps young learners understand how natural selection shapes animal traits across generations over very long periods of time, using the transition from dinosaurs to birds as a prime example and explaining why ‘evolution’ during the individual lifetimes of familiar Pokemon characters cannot really occur.  Amanda Snow’s unit combines instruction on geology and evolution to help middle school students understand Earth’s geological history through an evolutionary lens, emphasizing the fossil record and adaptations that allow organisms to thrive in the face of historical shifts in the planet’s climate. Thomas Teague’s unit for middle school students concerns transitional forms (‘missing links’) and the clear evidence for evolutionary change over time in familiar groups of organisms, such as the well-documented fossil transition from land-dwelling to ocean-dwelling traits during the evolution of whales. Vanessa Vitug’s unit is designed for high school students and concerns the ability for evolution to inform our understanding of human physiology and disease (‘evolutionary medicine’), particularly how the unique evolution of the human brain may cause its greater vulnerability to diseases such as Alzheimer’s and illnesses caused by prions (infectious proteins).

Paul E. Turner