The Geographic Mosaic of Sex and the Red Queen Kayla C. King, Lynda F. Delph, Jukka Jokela, Curtis M. Lively  Current Biology  Volume 19, Issue 17, Pages 1438-1441 (September 2009) DOI: 10.1016/j.cub.2009.06.062 Copyright © 2009 Elsevier Ltd Terms and Conditions

Figure 1 Depth Profile for Lake Alexandrina, South Island, New Zealand The arrows show the hypothesized outcome of parasite gene flow, resulting from the foraging behavior of the final hosts (grey ducks and New Zealand scaup). The shallow water (0–3 m) is expected to be a source of parasite gene flow because grey ducks forage mostly in the root and rock zones and New Zealand scaup forage mainly in the Isoetes zone. Both species of waterfowl rest on the surface over the deeper water but do not forage below ∼3 m. As a result, parasite genes are expected to be primarily recycled in the shallow water (red arrows), suggesting that the shallow-water margins of lakes are coevolutionary “hot spots.” Conversely, deep-water habitat (Elodea zone > 4 m) is hypothesized to be a coevolutionary “cold spot.” Larval parasites in the deep water are less likely to be eaten by ducks, and thus infections are not recycled back into the snail population (blue arrow). Current Biology 2009 19, 1438-1441DOI: (10.1016/j.cub.2009.06.062) Copyright © 2009 Elsevier Ltd Terms and Conditions

Figure 2 Frequency of Males in the Snail Populations “Shallow” (red) and “deep” (blue) refer to corresponding depth-specific habitat zones of Lake Alexandrina and Lake Kaniere. Vertical bars indicate ±1 standard error of the mean (SEM). Shallow habitats had a significantly higher frequency of males than deep habitats within Lake Alexandrina (t34 = 15.450, p < 0.001) and Lake Kaniere (t34 = 2.811, p = 0.008). ∗p ≤ 0.001. Current Biology 2009 19, 1438-1441DOI: (10.1016/j.cub.2009.06.062) Copyright © 2009 Elsevier Ltd Terms and Conditions

Figure 3 Experimental Infection Frequency of Microphallus in the Snail Populations “Shallow” (red) and “deep” (blue) refer to corresponding depth-specific habitat zones of Lake Alexandrina and Lake Kaniere. Vertical bars indicate ±1 SEM. ∗p ≤ 0.001. (A) Lake Alexandrina parasites. (B) Lake Kaniere parasites. (C) Lake Poerua parasites. Current Biology 2009 19, 1438-1441DOI: (10.1016/j.cub.2009.06.062) Copyright © 2009 Elsevier Ltd Terms and Conditions