Various evolutionary forces shape the human skeleton

Senckenberg Centre for Human Evolution and Palaeoenvironment at the University of Tübingen explores skeletal features as an alternative to DNA analysis

Tübingen, 10.08.2023 
Genetic kinship analyses of human bones reach their limits if the DNA is poorly preserved or if destructive sampling is not possible. New research shows that in such cases, comparisons of the structure and shape of certain parts of the skeleton may also provide detailed information about relationships, and do so non-destructively. This is the result of a large-scale study by an international research team led by Dr. Hannes Rathmann and Professor Katerina Harvati from the Senckenberg Centre for Human Evolution and Palaeoenvironment and the Institute for Archaeological Sciences at the University of Tübingen. 
The team analyzed large genetic and skeletal datasets to determine the extent to which human genetic diversity worldwide is reflected in the morphology – i.e, the structure and shape – of skeletal parts. The researchers obtained the best results when comparing certain dental and cranial elements, yet they also found that some worked significantly better than others and this difference is likely the result of how they evolved. This basic research may be used as a reference in future archaeological and forensic investigations to arrive at more robust inferences when DNA analysis is not possible. The study has been published in the journal PNAS Nexus. 

 Skeletal elements preserve differing evolutionary forces

Human skeletal morphology is highly diverse and varies among individuals and populations around the globe. This diversity is the result of a complex interplay of various evolutionary forces over a long period of time. “Evolutionary biologists divide these forces into two distinct processes. A neutral process refers to mutations producing new diversity which, however, offers no direct advantages or disadvantages to the affected individuals. This new diversity then increases or decreases randomly via what is known as genetic drift within a population,” explains Hannes Rathmann. “This is contrasted with non-neutral processes, for example, when mutations do affect the fitness of an individual. As a result, the affected individuals have a greater or lesser ability to adapt to environmental factors,” he says. To draw detailed conclusions about underlying genetic kinship, he says, only skeletal elements that evolved through neutral processes should be used. 
In the study, the team focused on the teeth and skull, whose structures are considered to have evolved primarily through neutral processes. “Contrary to earlier assumptions, not all features in the teeth and skull reliably reflect the underlying genetic code; some are much more suitable than others,” Rathmann says. Small morphological features on the teeth, such as groove patterns in the crowns, the number and size of cusps, the shape of the roots, and the presence or absence of wisdom teeth, proved to be particularly suitable. “However, we obtained the best results, almost identical to a conventional genetic relationship analysis, when we included all features of the skull and teeth,” he says. “This is also expected, as more skeletal features provide a richer knowledge of underlying genetic information,” he adds. 

A non-destructive alternative 

Katerina Harvati, the study’s senior author, adds, “The results enhance our understanding of the origins of human skeletal diversity. They are also promising for several direct applications in archaeological and forensic investigations.” Genetic analyses are often constrained by poor DNA preservation. This is commonly the case with very old bones or those that have been exposed to a warm climate, Harvati explains. Damaging bones for DNA analyses is also often out of the question in the case of fragile material or rare finds, or due to ethical reasons. “In such cases, the non-destructive examination of skulls and teeth is a valuable alternative for tracing past population history and hominin phylogeny in archaeological contexts, for example, or for infering ancestry profiles in forensic cases. This work, therefore, has implications for the scientific community and society at large,” Harvati says. 

Hannes Rathmann, Silvia Perretti, Valentina Porcu, Tsunehiko Hanihara, G. Richard Scott, Joel D. Irish, Hugo Reyes-Centeno, Silvia Ghirotto, Katerina Harvati (2023): Inferring human neutral genetic variation from craniodental phenotypes. PNAS Nexus, Volume 2, Issue 7, pgad217, 



Dr. Hannes Rathmann
wiss. Mitarbeiter

Current position
Research associate / Curator of the Human Osteological Collection

Research interests
Hannes Rathmann is a Bioarchaeologists specialized in human osteology, dental morphology, population and quantitative genetics, bioinformatics, and programming. His research interests center primarily around questions relating to human migration in the past. He worked on different archaeological projects including the reconstruction of the ancient Greek colonization of the Mediterranean; hunter-gatherer mobility in Ice Age Europe; and out-of-Africa dispersal models. He has conducted fieldwork in several European countries. His work promotes interdisciplinary synergy between Physical Anthropology, Paleogenetics and Archaeology.

University Education

2014 – 2018
Ph.D. Archaeological Sciences / Paleoanthropology (magna cum laude)
Institute for Archaeological Sciences, University of Tübingen
Supervisors: Professor Katerina Harvati and Professor Richard Posamentir

2011 – 2013
M.Sc. Archaeological Sciences / Paleoanthropology (magna cum laude)
Institute for Archaeological Sciences, University of Tübingen
Supervisors: Professor Joachim Wahl and Professor Heinrich Härke

2008 – 2011
B.A. Pre- and Protohistory and Medieval Archaeology (magna cum laude)
Institute for Pre- and Protohistory and Medieval Archaeology, University of Tübingen
Supervisors: Professor Joachim Wahl and Professor Martin Bartelheim

Previous Employments in Academia

2018 – 2019
Research Fellow at the DFG Center for Advanced Studies “Words, Bones, Genes, Tools: Tracking Linguistic, Cultural and Biological Trajectories of the Human Past”, University of Tübingen

Research Assistant at the DFG Center for Advanced Studies “Words, Bones, Genes, Tools: Tracking Linguistic, Cultural and Biological Trajectories of the Human Past”, University of Tübingen

2015 – 2017
Doctoral Fellowship through the Gerda Henkel Foundation, Düsseldorf.

Research Assistant at the Senckenberg Centre for Human Evolution and Paleoenvironment, University of Tübingen

Research Assistant at the Institute of Classical Archaeology, University of Tübingen

Research Grants

2015 – 2017
Doctoral dissertation grant of the Gerda Henkel Foundation (57,850 Euro).

Publications in Peer-Reviewed Journals (by December 2022)

Rathmann H, Stoyanov R, Posamentir R (2022). Comparing individuals buried in flexed and extended positions at the Greek colony of Chersonesos (Crimea) using cranial metric, dental metric, and dental nonmetric traits. International Journal of Osteoarchaeology. 32 (1): 49-63.

Rathmann H, Reyes-Centeno H (2020). Testing the utility of dental morphological trait combinations for inferring human neutral genetic variation. Proceedings of the National Academy of Sciences USA. 117 (20): 10769-10777.

Rathmann H, Kyle B, Nikita E, Harvati K, Saltini Semerari G (2019). Population history of southern Italy during Greek colonization. American Journal of Physical Anthropology 170 (4): 519-534.

Rathmann H, Reyes-Centeno H, Ghirotto S, Creanza N, Hanihara T, Harvati K (2017). Reconstructing human population history from dental phenotypes. Scientific Reports 7: 12495.

Reyes-Centeno H, Rathmann H, Hanihara T, Harvati K (2017): Testing modern human out-of-Africa dispersal models using dental non-metric data. Current Anthropology 58 (S17): S406-S417.

Rathmann H, Saltini Semerari G, Harvati K (2017). Evidence for migration influx into the ancient Greek colony of Metaponto: A population genetics approach using dental nonmetric traits. International Journal of Osteoarchaeology 27: 453-464.

Press Material

Skulls excavated from an archaeological site.  


Pressemeldung menschliche Skelette

Comparison between worldwide genetic diversity and morphological diversity of skulls and teeth. The world map above shows an overview of the samples studied (A). The six graphs below show the relationships of the samples based on DNA data (B) and on various morphological skull and tooth data (C-G). A grouping of points indicates close relationship. The morphological data overall yields similar, though not identical, results to the DNA-based kinship analysis. Image