Are tick populations really less variable and should they be?

Empirical evidence from electrophoretic examinations of Metastriate ticks does not support the prediction that these ectoparasites necessarily have low levels of genetic variability within populations and large interpopulation differences. In part, the failure of the theory to produce a parsimonious prediction seems to stem from the use of an inappropriate model based on spatial environmental heterogeneity. The experimental data are better explained in terms of host mobility, tick population size, and the degree of host specificity of the tick.