Posted on 04/25/2020 9:17:57 PM PDT by SunkenCiv
Human tooth shape varies greatly among individuals and populations. Examples of common dental features include the groove patterns in crowns, the relative size of cusps, the number of roots, and the presence or absence of wisdom teeth. These dental traits are heritable, with certain traits commonly observed within families. Some of them occur at different frequencies across populations in a way that is similar to the inheritance and variation of DNA. "Dental traits can be used in population genetic studies when DNA is not available," says Hannes Rathmann. Teeth are the hardest tissue in the human body and individuals' dental remains are often well preserved, even when associated skeletal and DNA preservation is poor...
"For this study we developed an algorithm that could compare DNA data against commonly used dental traits and all the possible combinations of these traits," explains Rathmann. The researchers performed extensive calculations and looked at more than 130 million possible combinations of dental traits. This enabled them to identify a set of highly informative trait combinations that preserve neutral genetic signals best -- making them the most useful for reconstructing genetic relationships.
The findings could be applied in many different contexts, including the identification of unknown individuals in forensic cases, the investigation of mobility of ancient populations in archaeological studies, and the reconstruction of the origin and evolution of our species using human fossils in paleoanthropological research... says Reyes-Centeno... "We propose that future studies should prioritize the most effective dental traits and trait combinations found in our study, as they allow more accurate conclusions to be drawn about genetic relationships." Including non-neutral dental traits could otherwise skew the results of the genetic analysis, the researchers say.
(Excerpt) Read more at phys.org ...
The Neandertal Enigma"Frayer's own reading of the record reveals a number of overlooked traits that clearly and specifically link the Neandertals to the Cro-Magnons. One such trait is the shape of the opening of the nerve canal in the lower jaw, a spot where dentists often give a pain-blocking injection. In many Neandertal, the upper portion of the opening is covered by a broad bony ridge, a curious feature also carried by a significant number of Cro-Magnons. But none of the alleged 'ancestors of us all' fossils from Africa have it, and it is extremely rare in modern people outside Europe." [pp 126-127]
by James Shreeve
in local libraries
Just sayin'.
girls with canines are hot
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