Like Finches, Only Wackier and With Guns

The This American Life podcast  "Good Guys" is a mixed bag, but the last story (Act 4) takes a turn into strange territory -- an anonymous soldier sent producer Sarah Koenig a number of recordings he made while on a tour of duty in Afghanistan, and he describes a group of men who joined the army not for love and country and patriotism, but instead to be able to experience the thrill of killing another human being . . . and while on some level this is disturbing, on another it makes me wonder if humans are just becoming more specialized, the way the finches did on the Galapagos Islands: now you can make your way in this world as a political pundit, a math nerd, an architect, a musician, a professional athlete, and as a killer . . . you can exploit your artistry, anger, rhetorical powers, mathematical skills,  good looks, ruthlessness, business sense, good will towards all humans, or any number of oddball human traits to earn money and gain fame and favor, so it makes sense that the killing niche will find its experts as well, and they aren't necessarily going to be doing it for the "right" reasons . . . in fact, if they are doing it for the "wrong" reasons, then they might be better at it (but also immoral) just like these guys were really good at making money . . . and if the niche exists, just as it would in an evolutionary matrix, something is going to move into it and exploit it, and you really can't blame people or animals or weeds or finches or whatever, if they do.