Investigating insects in a warming world

Instructional Unit on Adaptation and Evolution: Phenotypic/Genotypic Response to Climate Change in Lady Beetles

Overview

Read about the corresponding research of Elizabeth Dahlhoff and Nathan Rank

The Beetle Project uses insects as a model system to illustrate the biological impacts of climate change, with the goal of engaging students with a range of hands-on and minds-on activities that increase their understanding of how science works, evolutionary processes, and the impacts of climate change. Module components can be combined in different ways and include:

• a set of whole-organism/behavior lab activities using lady beetles (also known as ladybugs or ladybird beetles)
• a paper-and-pencil Data Nugget data analysis activity
• reading with discussion questions that highlights scientific research paralleling student lab activities
• extension lessons drawn from freely available materials produced by the University of Florida
• extension lessons for AP Biology.

Suggestions are included to adapt materials for students who need more or less scaffolding, and for classrooms with greater or lesser access to lab resources.

Instructional level: high school biology, AP Biology, college-level introductory biology

Curriculum overview

Lesson 1 investigates the question, “How are organisms responding to rapid ecosystem change?”. Students will understand that climate change involves not only global warming but also increased weather extremes and seasonal shifts. They will learn how certain kinds of insects survive the winter. Optional additions and extensions teach students to distinguish between genotypic and phenotypic variation, explain the concept of phenotypic plasticity, and identify particular species that may be better suited to survive extreme climate events.

In Lesson 2, students are introduced to lady beetles as a model organism. Students use their learning to explore how lady beetles might respond to environmental temperature change.

Lesson 3 allows students to test their exploratory ideas. Different lab options include:

• A guided inquiry lab, in which students measure the Chill Coma Recovery Time of beetles from a known geographical location and compare it to beetles from other locations.
• An open inquiry lab, in which students design and conduct their own experiments to measure Chill Coma Recovery time as a function of self-identified variables.
• A dry lab/data analysis option; which may be used if either inquiry lab is not feasible, or as an extension.

The laboratory experiment in brief: A useful, quantifiable trait in lady beetles and their relatives is their natural ability to enter Chill Coma.  Chill coma is a reversible total paralysis; emergence from chill coma can be timed.  This measurable parameter is known as Chill Coma Recovery Time (CCRT). CCRT may show both geographic variation among lady beetle populations, and temporal variation during different seasons. Students place groups of live lady beetles into culture tubes and immerse the tubes in crushed ice. After 24 hours, students time the emergence of their beetles from Chill Coma. Class results are compiled and compared to existing outcomes.

Pacing guide (based on 1-hour lessons)

Suggested prerequisite knowledge:

• Basic understanding of the causes of global climate change
• Basic graphing and statistics (histograms, mean, standard error)

LESSON 1 (1 lesson period)

1. Short film + discussion
2. Article: “Extreme Weather”
3. Student research: “How do insects survive the winter?”

LESSON 2 (1 lesson period)

1. Introduction to lady beetles
2. Student design of experiment

LESSON 3 (2 lesson periods)

1. Guided inquiry lab (2 lesson periods) OR open inquiry lab (2+ lesson periods)
2. Data Nugget (1 lesson period)

Optional elaboration/extension lessons (1-3 lesson periods, suggested placement: during or after Lesson 1)

1. Introduction to phenotypic plasticity
2. Whiplash weather and phenotypic plasticity
3. Student activity: “Winners and Losers”

AP-level lesson sequence with different pacing is available in the first tab below.