Evolution in Action: Data Analysis
These two activities allow students to analyze a data set of measurements taken from two populations of Galápagos finches. The activities support concepts covered in the short film The Beak of the Finch.
Students graph and analyze authentic data provided by evolutionary biologists Peter and Rosemary Grant. The data include wing length, body mass, and beak depth, and were taken from a sample of 100 medium ground finches (Geospiza fortis) living on the island of Daphne Major in the Galápagos archipelago. The complete data set is available in the accompanying Excel spreadsheet.
In the graphing activity, students are guided through the analysis of this sample of the Grants’ data by constructing and interpreting graphs, and calculating and interpreting descriptive statistics (mean, standard deviation, and 95% confidence interval). In the statistics activity, students analyze the data set using statistical tests, such as the Student’s t-test for independent samples, to help draw conclusions about the role of natural selection on morphological traits based on measurements.
Student Learning Targets
- Graph primary research data using both bar graphs and a scatter plot graph.
- Evaluate the evidence provided in data sets in relation to a particular scientific question.
- Analyze the means between data sets with t-tests to determine the significance between data sets.
- Construct explanations using evidence about the role of natural selection on morphological traits, based on the measurements.
- Propose hypotheses to explain the trends illustrated in the graphs, based on an understanding of natural selection.
confidence interval, histogram, mean, sample, standard deviation, trend line, t-test, variability
Grant, Rosemary B., and Peter R. Grant. “What Darwin's Finches Can Teach Us about the Evolutionary Origin and Regulation of Biodiversity.” BioScience 53, 10 (2003): 965–975. http://bioscience.oxfordjournals.org/content/53/10/965.full.pdf.
HS-LS2-2, HS-LS4-3, HS-LS4-4; SEP4, SEP5, SEP6
EVO-1.D, EVO-1.E, EVO-1.M, EVO-1.O, EVO-3.A; SP1, SP2, SP3, SP4, SP5, SP6
5.2, C.1, C.5
II.A, II.C, III.A
Math.F-IF.7, Math.S-ID.1, Math.S-ID.2, Math.S-ID.3, Math-S-ID.4, Math.S-IC.1, Math.S-IC.3; MP1, MP2, MP5
CC1, CC5; DP1, DP2