Understanding Evolution: your one-stop source for information on evolution
Resource library Teaching materials Evolution 101

Teaching materials : Image library:

To save: right-click (Windows) or control-click (Mac) on the image and select "Save image."

Genetic drift - Small population

Image caption:
The marble-drawing scenario also illustrates why drift affects small populations more. Imagine that your bag is only big enough for 20 marbles (a tiny bag!) and that you can only draw four marbles to represent gene frequencies in the next generation. Something like this might happen:

See the Understanding Evolution page where this image appears.

<< Back to search results

Image credit:
If you use this image in your own non-commercial project please credit it to the University of California Museum of Paleontology's Understanding Evolution (http://evolution.berkeley.edu).