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Hank: There’s a new set of ancient human fossils out there! In two papers published on Wednesday in the journal Nature, two teams of researchers announced that they’d discovered the fossilized remains of at least three tiny hominins on the isolated island of Flores, Indonesia. And the finds are helping scientists piece together how humans evolved.

The fossils are at least 700,000 years old, and they’re thought to belong to the ancestors of the ancient human species Homo floresiensis -- otherwise affectionately known as “Hobbits,” because they were only about a meter tall. Hobbit remains from 50,000 years ago, along with stone tools, were first discovered in 2004 in the Liang Bua cave, also on Flores. And since then, there’s been a lot of controversy about where they fit on the human evolutionary tree.

But with this discovery of what seem to be some of their ancestors, that mystery is one step closer to being solved. There are lots of reasons to think that these are the remains of ancestors of the previous finds -- the Homo floresiensis who lived hundreds of thousands of years later. For one thing, the fossils were found in a layer of sandstone in the Mata Menge, a site in the So’a Basin in central Flores -- only 70 kilometers from the Liang Bua cave, where the Hobbit remains were first discovered. Plus, the jaw and teeth are very similar to those of the Hobbits -- though they are a bit smaller. The stone tools found in the same sandstone layer were also a lot like to the tools used by the later Hobbits -- so they were using the same technology for a really long time.

So scientists are pretty sure that the hominins found at Mata Menge are the ancestors of Homo floresiensis. And the species has been puzzling scientists for years, for two main reasons. For one thing, they were very small: at first, researchers actually thought the remains might have been of more modern humans with some kind of disorder. But then they found more specimens. And after studying them some more -- including their skull structure -- they realized that they were looking at a whole new species of human, one that had evolved to be much shorter. And we still don’t really know why.

Which brings us to the second mystery: how did Homo floresiensis evolve? See, their skulls look a lot like those of the much older Homo habilis, which lived between 2.4 and 1.4 million years ago, and Homo erectus, which lived between 2 million and about 100,000 years ago. But their skeletons seem much more primitive. In fact, they’re similar to the skeletons of one of our earlier ancestors, Australopithecus afarensis, which dates back more than 3 million years. So, the question becomes, did Homo floresiensis evolve from Homo erectus? Or from more ancient Homo habilis... or even from Australopithecus?

The new finds seem to point to Homo erectus. In 2014, ten years after the first Hobbit specimens were discovered, researchers discovered seven more fossils, including part of a jaw and six teeth. They believe that the jaw and some of the teeth belonged to the same adult, while two of the teeth belonged to two different infants. It’s hard to eliminate Australopithecus as a possibility without a more complete skeleton, but the shape of the newly-found jaw and teeth showed some similarity to the teeth of early Homo erectus -- more so than Homo habilis.

Which is weird, because Homo erectus was about half a meter taller than Homo floresiensis, so they would have had to have shrunk VERY quickly, on an evolutionary timescale -- within about 300,000 years. Until we find and study more fossils, it will be hard to know for sure where Homo floresiensis belongs on the evolutionary tree. But the new Mata Menge fossils are helping us understand a little more about how ancient human life developed.

And speaking of discovering other humans, SciShow is adding a new human to our team! You know me, and Michael Aranda, but I would like you to meet Olivia Gordon! Olivia joined us on Talk Show at the Insectarium a few months back, and a lot of people requested more of her, so you're getting more of her. Olivia will now be hosting and sharing her knowledge with us regularly!

Olivia: Hi guys! I’m excited to be here.

Hank: Some of you already got to meet Olivia and ask her some questions during our June Patreon Livestream, so Olivia, would you like to do the Patreon thing that we do at the end of the episode?

Olivia: Sure! This episode of SciShow News was brought to you by our Patreon Patrons. If you want to help make videos like this, you can go to Patreon.com/scishow to learn more and don’t forget to go to youtube.com/scishow and subscribe! That was good!