Sweet potatoes/yams tends to get a pass, while "normal" potatoes are generally avoided by the paleo community. What about yucca/cassava? Are they nutrient dense like yams, or are they more like normal potatoes?
Weird coincidence, I'm actually eating some right now. Not because it's paleo, but because its a traditional dish of Kerala that my family eats on occasion.
They're somewhere in between potatoes and sweet potatoes, though many avoid them because of the partly-psychological fear produced by the toxin content of the root. They do have significant vitamin and mineral content, and after being cooked, low levels of anti-nutrients (they contain no enzyme inhibitors at all). The steroidal saponins they contain may actually be healthful, upregulating testosterone (this is far from clear).
But they don't hold a candle to sweet potatoes.
From Mark's daily apple: http://www.marksdailyapple.com/difference-yams-sweet-potatoes/