Research reveals a surprising link between the evolution of teeth and pregnancy

Humans have the highest prenatal growth rate of any extant primate, but how this exceptional rate occurs has remained a mystery until now. Leslea Hlusko, a scientist at the Centro Nacional de Investigación sobre la Evolución Humana (CENIEH), took part in a study by Tesla Monson, a paleoanthropologist at Western Washington University (WWU) in the US, looking at teeth, prenatal growth. rates and evolution of pregnancy. This study revealed a key piece of this puzzle in an unexpected place: the relative sizes of fossilized molars.

Teeth are an indicator of what is happening elsewhere in the body, and the study was published in the journal Proceedings of the National Academy of Sciences (PNAS).suggests that it can be used as a map to unravel the interplay between genetics and development, as well as improve our understanding of the history of life in the past.

Tesla Monson and Andrew Weitz of WWU’s Department of Environmental Sciences, a team including scientists from the Berkeley Geochronology Center (USA) and CENIEH studied the fossils of the primate group, which includes Old World monkeys and apes. as well as data collected from fossilized molars and skull fragments from the terminal Miocene to the Plio-Pleistocene, which spanned from about six million years ago to about 12,000 years ago.

The results show that hominids A million and a half million years ago, they reached the prenatal growth rate that set them apart from all other apes. human species evolved itself (300,000 to 200,000 years ago).

molars

Prenatal growth rate is closely related to endocranial volume and, surprisingly, to variation in molar proportions. “This suggests that teeth can be an indicator of both prenatal growth rate and brain size. the fossil record“, says Hlusko.

The discovery of the relationship between these ratios molars and prenatal growth rates have raised many new questions for evolutionary researchers, such as understanding the underlying genetic mechanisms. One of the main questions is whether this also happens in other mammals.

“While I don’t think our humanity can be reduced to just teeth, I do believe that part of it is ours teeth🇧🇷 This work opens a window for pregnancy and pregnancy research. We can take dental material from human ancestors and other fossils primates to find out what their pregnancies are like,” Monson concludes.