How did our ancestors use their feet? Evidence of bipedalism and climbing from internal bone structure.

Project Information

FOOTSTEP

Grant agreement ID: 101025719

DOI

10.3030/101025719

Project terminated on 31 January 2023

EC signature date 8 July 2021

Start date 10 January 2022

End date 9 January 2024

Funded under

• EXCELLENT SCIENCE - Marie Skłodowska-Curie Actions

Total cost

€ 212 933,76

EU contribution

€ 212 933,76

Coordinated by

UNIVERSITY OF KENT
United Kingdom

Periodic Reporting for period 1 - FOOTSTEP (How did our ancestors use their feet? Evidence of bipedalism and climbing from internal bone structure.)

Reporting period: 2022-01-10 to 2024-01-09

Summary of the context and overall objectives of the project

The FOOTSTEP project addressed longstanding questions about the evolution of locomotion in fossil human relatives. We know that at some stage in our evolutionary history, we transitioned from an ape-like ancestor that spent a large amount of time in the trees, to a committed, terrestrial biped. However, the mode of this transition is as yet unclear. Recently, new discoveries of fossil human relatives (hominins), have shown that different species may have used different types of bipedal locomotion and some may have spent a substantial amount of time climbing in trees.
To reconstruct locomotor behaviour in our fossil relatives, the objectives of FOOTSTEP were to analyse the internal bone structure of the foot in humans, non-human ape species that are alive today, and in several fossil hominins. This is because the internal bone structure of the skeleton remodels during life in response to behaviour and so can reveal how an individual actually behaved. The three Research Objectives were: (RO1) establish the relationship between internal bone structure and locomotion in the foot of living groups; (RO2) compare internal bone structure of the foot among active and sedentary human groups; and (RO3) reconstruct foot loading in key hominin taxa. This has societal implications, as understanding the diversity of anatomy among living humans and fossil hominins, and their biomechanics, has relevance for understanding the evolution of the modern human foot, with implications for clinical medicine.

Work performed from the beginning of the project to the end of the period covered by the report and main results achieved so far

To address RO1, to explore differences in the internal bone structure of the feet of living taxa, the bone structure of the metatarsals was analysed and differences between humans and apes were found in the distribution of bone within the joints and in the relative strength of the bones across the foot. Internal bone structure of the ankle was explored across humans and non-human apes and differences in bone distribution related to locomotion were identified. To address RO2, exploring variability across human groups, micro-CT scans were collected from a diverse range of human populations – from two active human hunter gatherer populations and from Tudor soldiers from the Mary Rose shipwreck. This data will be analysed in future to explore variability among human groups. The goals of RO3 were addressed by analysing the internal bone structure of the foot and ankle of Australopithecus africanus from Sterkfontein, and the foot of Homo floresiensis, the short-statured hominin from the Indonesian island of Flores. Future research will continued to explore the internal bone structure of the foot and ankle of these taxa, as well as that of Homo naledi and Australopithecus sediba. The FOOTSTEP project was terminated early, due to the researcher taking up a position as a tenure-track Assistant Professor in the USA. However, future research will, through ongoing collaboration between the researcher and supervisor, continue to address the FOOTSTEP research objectives.
Project results were disseminated at two international conferences in 2022: the Annual Meeting of the American Association of Biological Anthropologists and the European Society for the study of Human Evolution. Futher, results will be disseminated in international conferences in 2023, via two abstracts at the Annual Meeting of the American Association of Biological Anthropologists and one abstract at the International Congress of Vertebrate Morphology. Results of the analysis of the foot of Homo floresiensis will be presented at the Liang Bua MicroCT Workshop (9th-13th October 2023), to ensure results are disseminated to scientists whose research involves material, both skeletal and archaeological, from the Liang Bua cave. Four research articles resulting from this research are currently in preparation to be submitted to academic journals. It is expected that the data collected and analysed during the project period will result in several additional publications in future.
During the project, the researcher received training in novel methods for analysis of internal bone structure, including segmentation methods and application of geometric morphometric based approaches to statistically compare internal bone structure between groups. The researcher also contributed to the supervision of one Masters student and three doctoral students.

Progress beyond the state of the art and expected potential impact (including the socio-economic impact and the wider societal implications of the project so far)

The innovative aspects of the FOOTSTEP project that have progressed beyond the state of the art include two aspects of the methodological approach. Firstly, the FOOTSTEP project has used recently developed cutting-edge methodological approaches for analysis of the internal bone structure. This has allowed for holistic analysis of the internal structure of the foot and ankle. Secondly, by applying this approach to multiple skeletal elements, the project has allowed a more comprehensive understanding of internal structure among living and fossil groups.
The FOOTSTEP project has, and will have, some broader impacts. During the FOOTSTEP project, the researcher contributed to outreach projects involving four local primary schools. This experience provided the students with an introduction to ideas surrounding human evolution, and positive feedback was provided from the teachers on the experience. In addition, the project will benefit the scientific community, in that data collected during the project period will be hosted on the Human Fossil Record Archive, an online archive hosting micro-CT and surface data relevant to human evolution research, to make data available to other researchers. Approval for access to the data is determined by the curatorial institution, as is standard in the field.

With graduate student collaborator Samar Syeda

Outreach activity with primary school students

With collaborator Dr Selim Natahi