Physical barriers to gene flow

Physical barriers to gene flow

Physical barriers can prevent gene flow, or the transfer of alleles of genes, from one population to another. Though these barriers are usually natural, such as a desert or river, the Great Wall of China has hindered the gene flow of native plant populations

Photo: Billy Matthews, http://www.flickr.com/photos/billaayy/. Licensed under Creative Commons Attribution-Noncommercial-Share Alike 2.0 Generic