Research on toxoplasma in wolf populations: "The effect of TOXO[toxoplasma positive test] was positive ...With an odds ratio of 46.06 (exp[3.83]), the odds that a seropositive wolf becomes a pack leader is more than 46 times higher than a seronegative wolf becoming a pack leader."
Extraordinary result. I think one would need to do an experimental infection to be sure that this is not due to some complex confounder. But super-interesting idea.
Paper here: