I still remember how torn I was when I first read about the counter-intuitive possibility that natural selection could favor suicide. Apparently, sometimes one can increase one’s inclusive fitness by looking into barrel of a gun. Now, as it turns out, natural selection can favor also functional necrophlia. Read more about it from here, or consult the original publication. And who are these corpse humpers? Our beloved frogs.
Izzo et al (2012) Functional necrophilia: a profitable anuran reproductive strategy. Journal of Natural History 46:2961-2967.