Simbio Virtual Labs: Evobeaker Chapter Summary

SimBio Virtual Labs®

EvoBeaker®: Finches and
Evolution
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SimBio Virtual Labs®: EvoBeaker®

Finches and Evolution
Introduction
In 1835, while traveling with the British Survey ship HMS Beagle, Charles Darwin, then 26 years old, visited the Galapagos archipelago. During a five-week stay,
When parents reproduce, they pass to each offspring one of their two gene copies for each locus. Beak widths can vary from 5 mm to 12 mm.
The Parameters panel now includes sliders allowing you to set the Best value for both beak depth and beak width, and sliders allowing you to adjust the Selection strength for each trait. The higher the selection strength for a trait, the more a finch’s value for that trait influences its success in local competition for food. For now, leave the Selection strength sliders at zero.

[ 3 ]

Variation among individuals is now displayed not in a bar graph but in a scatter plot. This is the lower of the two graphs on the right of the screen. Each of the dark dots on the graph represents an individual finch. (These dots may overlap, forming what appear to be bars.) The dot’s position along the horizontal axis indicates the finch’s beak depth; the dot’s position along the vertical axis indicates the finch’s beak width. The light-colored dot near the center of the cloud of points represents the population averages for beak depth and beak width.
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Predict what will happen to the population averages over time when you run the model. © 2013, SimBio. All Rights