Periodic Reporting for period 4 - NewHuman (Pathways to humanity: Adaptive niche diversity at the origins of the human lineage)
Reporting period: 2024-01-01 to 2025-06-30
NewHuman was a project about the fossil record of humans and in particular about an enigmatic group of fossil species whose position in our branch of the Tree of Life is uncertain. Our novel approach to clarifying how these species fit into our evolutionary history was to study the structure of their bones and teeth to reconstruct how they lived and how they differed from other human ancestral species. In particular, we employed cutting edge imaging techniques that detect how individuals moved around during their lifetime and how they are related to each other. This is important to society because it will clarify when, where and how we became the humans we are today and in particular what behaviours were key to the initial appearance of humans. NewHuman focused on unexpected fossil discoveries over the last 20 years that have resulted in the identification of three new fossil human relatives. What made them unexpected was a combination of two things. First, they were unusually small-bodied and small-brained. Second, while two of these new species are found at a time near the origins of our own our group Homo, the other two are surprisingly recent, between 100-300,000 years ago. NewHuman tested the hypothesis that these species could represent a previously unrecognized adaptive niche in the human evolutionary story that persisted until the time that modern humans appeared. The main objectives of NewHuman were to conduct excavations in South Africa, Kenya and Indonesia to try and find more fossil remains of these enigmatic species, to CT scan all the fossils we have of these species in order to study the hidden structures of their bones and teeth, and to use this novel data to reconstruct how they behaved. How did they move around their environments? Did they spend considerable time climbing in an arboreal environment? Did they make and use stone tools? By answering these questions we hope to determine where these intriguing new fossil species fit into the story of human evolution. Over the course of six years NewHuman produced 52 scientific publications and our findings were presented at over 60 international scientific conferences. NewHuman also created an online archive of digital data: Human-Fossil-Record.org which is now the leading online archive devoted to human evolution. Finally, we developed new software tools for the analysis of bone structure which are applicable to a number of other scientific fields including clinical medicine, skeletal biology and vertebrate paleontology.
NewHuman created a database of microtomographic scans of all fossils belonging to Homo floresiensis (recovered from Liang Bua Cave, Flores, Indonesia and curated in Jakarta) as well as 1000s of bones of museum specimens belonging to extant primates (including the Powell-Cotton Museum, Natural History Museum in Berlin, the Natural History Museum in Munich, and the British Museum of Natural History). Many of these scans are now directly available through our online archive (Human-Fossil-Record.org) or will be available through the relevant curatorial institution via our archive. This archive of CT scans will provide for hundreds of future scientific studies of fossil hominins and collectively they represent a step-change in data access which has been notoriously difficult in the field of human evolution. We conducted archaeological fieldwork on the Indonesian island of Flores in 2022, 2023, and 2024. In 2022 and 2023, excavations were carried out at Liang Panas and Liang Verhoeven, two sites near the western coast. This work has led to the discovery of the oldest directly radiocarbon dated human bone on Flores––a hand middle phalanx dated to 21 thousand calibrated years before present. In 2024, excavations at Liang Bua recovered a large number of stone artefacts and faunal remains that are extending our understanding of the paleobiology and paleoecology of Homo floresiensis. We also collected hominin fossils from Chesowanja (Baringo County, Kenya). A large proportion of the research conducted by NewHuman was aimed at using internal bone structure to reconstruct behavior in fossil hominins. Most impactful were our demonstration of distinct locomotory repertoires in South African hominins (Georgiou et al 2020), the first evidence of hand loading behavior in A. sediba (Dunmore et al 2020), the first evidence of finger-loading and its impact on bone structure in A. sediba and H. naledi (Syeda et al 2025), and the first internal data on the ankle of H. floresiensis (Pietrobelli et al 2025a/2025b). Methodologically, NewHuman developed Canonical Holistic Morphometric Analysis of trabecular bone, which allows for more robust statistical analyses of internal bone structure. Our work also 1) improved our understanding tooth development, and 2) incorporated dental data into the systematic analysis of hominin evolution. Davies et al (2021) provided novel findings, interpretations and guidance on accessory cusp expression in hominin molars, we published the Primate Tooth Crown Morphology Framework for the interpretation tooth crown variation in all primates (Chapple et al 2023), demonstrated for the first time that a leading cusp patterning model is consistent with cusp variation in monkeys (Chapple et al 2024), reported a link between thermoregulatory stress and tooth defects in Japanese macaques (Skinner et al 2025), and revised the current nomenclature used to study primate tooth crowns (Chapple and Skinner 2023). Additionally, we produced a number of analyses of the Homo naledi dental sample (Davies et al., 2019, 2020; Delezene et al 2024), the first data on dental tissue growth in Homo naledi (Mahoney et al 2024), the first enamel periodicity data and stress events recorded in Homo naledi teeth (Skinner et al 2024), and a comprehensive catalogue of the entire dental hypodigm (Delezene et al., 2023). Davies et al (2023) published the first data on internal tooth structures of Homo habilis and we contributed to a number of high-profile publications on fossil hominins including: the earliest modern human fossils in Europe from Bacho Kiro (Hublin et al., 2020), the first Denisovan hominin remains from Laos (Demeter et al., 2022), our reattribution of a number of hominin specimens from South Africa (Zanolli et al., 2022), new Neanderthal remains from Axlor, Spain (Bailey et al., 2024), and the earliest Homo erectus from Ethiopia (Mussi et al 2023).
NewHuman produced important and never-before-seen data from human fossils, some of which have been in museum collections for over 70 years. Our virtual approach unlocked secrets about our past and provided important insights into the daily lives of our ancestors. Additionally, we made discoveries of new fossils in South Africa, Kenya and Indonesia that will enrich our understanding of the human branch of the Tree of Life. The software tools that we developed will be useful in other fields such as clinical medicine and particularly research focused on bone health (e.g. osteoporosis). The Human-Fossil-Record.org online archive is now the world leading source of for digital images and surface models of human fossils and is of immense value to students, senior researchers, teachers and members of the public.