In this video discussion, University of Chicago scientist Paul Sereno tells the NewsHour's Jeffrey Brown about how his team, looking for dinosaur bones in Niger, Africa, found two populations of humans in a burial ground; the bodies are 6,000 to 9,500 years old.

Sereno and his team found hundreds of bodies, which allowed them to compare height, health and stature of the various early humans. The find yielded two different types of humans, and Sereno explains via differences in two sample skulls he brings to the interview.

The find is also important because it is connected to climate change science: the Sahara desert where the bodies were found used to have vegetation, hippos, elephants and huge fish, but is now a very dry part of the world.

"Well, the surprise is that we get much more of the picture when you find hundreds of burials. You get entire bodies. You get stature. You get health. You really get a look at the lifestyle of these people. You get to understand what they were eating, what they're hunting." - Paul Sereno, University of Chicago

"Where these people came from, ultimately, and where they became the Tenerians, that's for future research. We're really interested, because the Sahara is inhabited today by some very interesting nomads. And we're wondering, ultimately, are we looking at the roots of that population?" -Paul Sereno

"I mean, basically, we want to know how the recent populations -- everybody wants to know how the recent populations relate to these ancient populations. Are we looking at the roots of the people who are living there today, the Egyptians, the Berbers, the Tuaregs?" - Paul Sereno

When did the earliest humans live? Where did they live? See if you can find a basic timeline.

Where is the Sahara desert? What are its characteristics?

Why is this find significant? How does this burial site help scientists learn about these early humans?
Is it important to learn about early humans? Why or why not?

Were you surprised to learn that this area of the desert used to be green? Do you think that relates to the current debate about global warming? Why did it become a dry desert?