Amazing stuff! It took from July 2023 preprint to May 2025 to publish this paper in a journal! This is almost unacceptable! Slower than a snail!
"... Instead, the authors of a new study turned to proteins, which survive much longer than DNA. By analyzing enamel from four P. robustus ["a heavy-jawed, thick-molared human relative that lived in southern Africa roughly two million years ago"] tooth fossils, researchers were able to determine the biological sex of each specimen—and were surprised to find that one tooth, initially thought to come from a female due to its small size, actually belonged to a male. “ Paleoanthropologists have long known that our use of tooth size to estimate sex was fraught with uncertainty ...
The analysis also revealed variation in a protein called enamelin and showed that one P. robustus individual was more distantly related to the other three specimens than they were to one another. Those findings may point to hidden genetic diversity within the Paranthropus genus, supporting the possibility of multiple distinct species. ..."
From the editor's summary and abstract:
"Editor’s summary
It is now well known that the early hominin fauna was species rich, with many overlapping lineages existing in the African Pleistocene. However, our knowledge of diversity within many of these lineages has been limited because current ancient DNA technologies have not been able to reveal genetic sequences older than around 0.2 million years. Madupe et al. examined protein sequences from approximately 2-million-year-old Paranthropus robustus teeth that were particularly well preserved. Using proteomics approaches, the authors were able to assign the individual teeth to sex and to identify patterns of diversity suggesting the existence of multiple populations.
Abstract
Paranthropus robustus is a morphologically well-documented Early Pleistocene hominin species from southern Africa with no genetic evidence reported so far. In this work, we describe the mass spectrometric sequencing of enamel peptides from four ~2 million–year-old dental specimens attributed morphologically to P. robustus from the site of Swartkrans in South Africa. The identification of AMELY-specific peptides enabled us to assign two specimens to male individuals, whereas semiquantitative mass spectrometric data analysis attributed the other two to females. A single amino acid polymorphism and the enamel-dentine junction shape variation indicated potential subgroups present within southern African Paranthropus. This study demonstrates how palaeoproteomics can help distinguish sexual dimorphism from other sources of variation in African Early Pleistocene hominins."
Males of this ancient human cousin weren’t always bigger than females "Proteins from a collection of fossils hint at sex and genetic differences in P. robustus"
Proteins from two-million-year-old teeth reveal unprecedented insights into extinct human relative (original news release)
Enamel proteins reveal biological sex and genetic variability in southern African Paranthropus (no public access)
Enamel proteins reveal biological sex and genetic variability within southern African Paranthropus (preprint, open access)
Fig. 1 Location and cave structure of the site of Swartkrans, South Africa. Plus teeth
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