The Ladybug Game: Interactive lessons on evolution.

This application and associated lessons are designed to introduce the fundamental components of evolution: selection, inheritance, and variation. The color and behavior of the aphids evolves under the selective pressure of ladybug predation. Each time the ladybug captures an aphid a different aphid is selected at random to reproduce. Offspring inherit their parent's color and behavior with small, random variations (except in lesson 3 where the effect of variation is investigated).

Variants of the game can be played as an on-line javascript program or an on-line applet. In addition, because variation in browsers and security settings may interfer with proper on-line play, there is also a stand-alone executable for Windows:
Windows (download, unzip, and run the .exe file)

Lesson 1: The user controls the ladybug. The user may target aphids of a particular color, mimicing selective breeding. Alternatively, the user may simply capture aphids as fast as possible, resulting in less predictable evolutionary outcomes.

Lesson 2: Compare the outcome of evolution in the two different environments. Typically, the aphids evolve to match their respective backgrounds, but in some case their behaviors may evolve more strongly than their colors. Once the aphids have similar colors try changing the backgrounds (using the color wheel). Note that it may take some time for a strongly convereged population to evolve dramatically different colors.

Lesson 3: Aphids in the lefthand environment don't mutate - they are identical to their parents. Initial variation in the lefthand population may lead to aphids similar to the background color, but changes in the background won't result in changes in the aphids' color once the population has convereged on a color.

Lesson 4: Aphids in the lefthand environment do not inherit traits from their parent - each offspring is completely random. Although well-fit aphids do emerge they do not pass thier traits onto their offspring, so the population as a whole does not adapt.

Lesson 5: The ladybug in the lefthand environment is effectively colorblind. Aphid color doesn't effect the probablity of capture. As a result there is no selection based on color and the aphids will generally not converge on the background color. Note that the aphids' color may eventually converge on some color due to chance.

This material is based in part upon work supported by the National Science Foundation under Cooperative Agreement No. DBI-0939454. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation.