Next year, we will start to learn what a host of ancient animal and early human remains really are, thanks to new techniques for identifying even fragmentary pieces.
Over the past decade, DNA analysis has overturned our ideas of human evolution. It has revealed that humans interbred with Neanderthals, and unveiled a hitherto-unknown group called Denisovans.
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鈥淓namel in teeth could help us identify mystery remains and put together a family tree for early humans鈥�
But it has limits. The DNA in remains doesn鈥檛 survive long when conditions are hot or wet, so we won鈥檛 get much from the tropics. Even in ideal conditions, DNA breaks down. The oldest DNA yet recovered comes from a horse that lived 700,000 years ago.
However, proteins can survive longer. One example is the collagen in bone, which can now be used to roughly identify organisms. The method is fast and cheap. Another technique is more precise. Enamel in teeth also contains proteins, which can reveal an animal鈥檚 species.
In September this year, Enrico Cappellini at the Natural History Museum of Denmark used the method on remains of extinct rhinos and figured out how the species were related. This proof of concept was huge, because teeth are the most frequently preserved body part.
The technique should shed light on human evolution. 鈥淲e have all these exciting fossils coming out of Africa, but we have no DNA to go along with them,鈥� says Samantha Brown at the Max Planck Institute for the Science of Human History in Germany. Newly discovered species like Homo naledi and Australopithecus sediba cause confusion because we can鈥檛 tell where they fit in our family tree. 鈥淓namel could be useful for putting together those trees,鈥� she says.
There is also the matter of finding a Denisovan skeleton. The species is known only from teeth and tiny bones, but a better specimen could already be in a museum 鈥� and enamel could unmask it.
This article appeared in print under the headline 鈥淣ews Preview 2019: Teeth shed light on evolution鈥�
