That's a cool graph, but contains something I find rather suspicious. Namely, it puts Homo neanderthalensis on the step before Homo sapiens. This is misleading, since HN and HS existed at the same time, and HS did not evolve from HN. See https://en.wikipedia.org/wiki/Neanderthal for details.
In any case, I'll definitely show this to my kids tomorrow. I always lecture them about evolution and how we can trace so much of our biological world to some evolutionary step millions of years ago. This graph should drive the point home better than any of my incoherent ramblings.