Life has evolved over millions of years. Yet evolution can produce dramatic change quickly! The coat color of gray squirrels, which occur over much of eastern North America and are introduced around the globe, is a good example. Today most are indeed gray but two centuries ago most were apparently black. How could evolution change this species so profoundly and so quickly? Help us explore this question at SquirrelMapper where you can contribute observations of squirrels from your own neighborhood, classify squirrles based on their color, and play a game that measure how well adapted each color squirrel is to its environment. Together we can crack this nut! By engaging SquirrelMapper you can contribute to an important scientific discovery about evolution in action in our own backyards. There are three ways you can participate: 1) Contribute observations of squirrels to the SquirrelMapper project on iNaturalist. Over 40,000 photographs of squirrels have been submitted so far. When you submit an observation, the community of citizen scientists at iNaturalist confirm its identification. Once an observation is confirmed to be an eastern gray squirrel (a research grade observation), we import the photo to our project site at Zooniverse for you to classify by its coat color. Please follow the steps, below to make sure your contributions are credited in SciStarter Dashboard: I. After you've created an iNat account, come back to SciStarter Dashboard > Info&Setting https://scistarter.org/dashboard/settings. Scroll down and enter your iNaturalist user name (case sensitive) in the section titled “Affiliation Integration”. II. You will start to see your participation recorded in your SciStarter Dashboard within 24 hours. Don’t worry–you won’t have to do this again. In the future, you can go directly to the iNaturalist app and your contributions will be synced to your SciStarter Dashboard. 2) Classify the coat color of squirrels as gray or black at the SquirrelMapper project on Zooniverse. The coat color of each squirrel is confirmed through classifications by at least 10 users at Zooniverse. Once the color of a squirrel is classified, we map it, identify its habitat, and determine which morph occurs more often where. This lets us understand how quickly squirrels, and mammals like them, can adapt to changes in their habitats. Please follow the steps, below to make sure your contributions are credited in SciStarter Dashboard: I. Click "Visit" II. From the Zooniverse platform (the host of this project) create a Zooniverse account using the same email address (case sensitive) you used to create your SciStarter account. Your Zooniverse account will include a username. III. Copy your Zooniverse username and paste it where instructed on your SciStarter dashboard's "Info & Settings" https://scistarter.org/dashboard/settings. IV. You'll only need to do this one time. In the future, you'll go straight to Zooniverse to participate and you'll earn SciStarter credit each time! 3) Directly measure natural selection on squirrel coloration by playing our Find the Squirrel game. In this game you will search for squirrels in scenes of old growth forests, secondary forests, and roads, and we measure how long it takes you to find gray and black squirrels in each scene. By participating in the game you will directly measure the selection pressures on black and gray squirrels in each environment. This game is fun and provides critical data on how easy (or hard) squirrels of different colors can be seen by predators.