Examples presented demonstrate that evolutionary outcomes depend not only on those processes that operate within populations(e,g.,selection) but also on interactions (via gene flow) among populations. Factors affecting rates of gene flow are likely to produce evolutionary change even when within-population processes remain constant. These examples also illustrate that the combined effects of selection and gene flow are not restricted to organisms found on islands like those in western Lake Erie but may be important in any organism whose distribution spans a range of habitat types. As human activities produce changes in habitat characteristics and distribution (e.g., by fragmenting formerly continuous habitats), changes in selection regimes and rates of gene flow may produce microevolutionary changes in other organisms that mirror those seen in island water snakes.
King, Richard B. and Lawson, R., "Microevolution in Island Water Snakes" (1997). Faculty Peer-Reviewed Publications. 761.
Department of Biological Sciences
American Institute of Biological Sciences