"Darwin's Nightmare" fully lives up to its chilling title, a cinema verite journey to the heart of darkness -- not, mind you, the heart of Africa, where it transpires, but to the murkiest reaches of human apathy and despair.

The documentary, which was made by Austrian filmmaker Hubert Sauper, examines a phenomenon that took root 40 years ago in Lake Victoria, in Tanzania, where, as a "little scientific experiment," the Nile perch was introduced to the thriving aquatic ecosystem. In short order, the voracious fish ate everything in its path, including other fish and the lake's plant species.

It turns out that, for Sauper, the Nile perch is an apt metaphor for the First World and its rapacious exploitation of Africa's natural resources. As the filmmaker informs viewers in one of several intertitles, 2 million white people eat Nile perch every day. In a stinging irony, precisely that number of Tanzanians are starving, able to consume only the fish heads and maggot-infested carcasses.

With unblinking, often sickening deliberation, Sauper methodically connects the dots that begin as seemingly unrelated interviews with Russian and Ukrainian cargo pilots, teenage Tanzanian prostitutes, orphaned children living on the streets and the chief of a multinational corporation called Simba. What gradually comes into focus is a terrifying, appalling, infuriating cycle of exploitation and corruption, with those pilots flying in weapons for Africa's myriad civil wars and flying out fish, leaving Tanzania impoverished and dying.

"Darwin's Nightmare" is many things, including an environmental cautionary tale, a critique of globalization and a portrait of a community, country and continent in deep crisis. But at its most profound level it's about the ways in which those of us on the receiving end of the supply chain routinely and unknowingly break faith with the most dispossessed and defenseless of the world.

-- Ann Hornaday

"Darwin's Nightmare" traces an "experiment" gone awry.