Researchers collected tail DNA from 312 mice at 15 locations in New York City. Once they analyzed each mouse’s DNA, the researchers wanted to get a sense of how related the populations were. They assigned mice with similar genotypes particular colors and sorted all the mice by location. They found that mice within a population shared more alleles with one another than they did with mice from other populations.
SOURCE: Munshi-South, J., and Kharchenko, K. (2010) Rapid, pervasive genetic differentiation of urban white-footed mouse (Peromyscus leucopus) populations in New York City. Molecular Ecology 19:4242–4254.