Q1: Why is this study important? What does the discovery of Denisovan fossils in Taiwan mean?

On the sea bottom of the Penghu Channel in the Taiwan Strait lies a fossil treasure trove, preserving numerous animal fossils that serve as crucial evidence for studying the migration, adaptation, and evolution of mammals across the Eurasian continent since the Quaternary. Human fossils are especially rare and valuable, and the discovery of a Denisovan fossil in Taiwan significantly expands our understanding of the Denisovans’ range of activity. It suggests that Denisovans were widely distributed across East Asia and parts of Island Southeast Asia. Furthermore, it demonstrates their ability to adapt to diverse environments—from the frigid regions of Siberia and the high altitudes of Tibet to the forest-steppe and wetland ecosystems of East Asia.

Q2: What are the limitations of the study?

The preservation and discovery of human fossils are not easy, and whether fossils can retain enough genetic material—such as ancient DNA and ancient proteins—for research and analysis often determines the scope of possible scientific inferences. Because the ancient genome or protein sequences in this study are not yet complete, it is difficult to support interpretations related to genetic variation in species.

Q1: Why is this study important? What does the discovery of Denisovan fossils in Taiwan mean?

Each hominin or human fossil has the potential to entirely rewrite or revise our understanding of how we evolved. This Denisovan man from Taiwan is one of those discoveries, which can be a highly representative study and also points out that Taiwan holds a significant position in understanding human evolution.

One of the representative results led by the 2022 Nobel laureate Svante Pääbo was successfully extracting ancient DNA of early humans, and published an unknown hominin from Siberia, later dubbed Denisovans. Outside Siberia, the only confirmed Denisovan with molecular evidence came from Tibet.

More interestingly, genomic studies of modern humans suggest that Denisovans were widespread across East Asia, Southeast Asia, and even Oceania. However, there is no confirmed Denisovans, especially with decisive molecular evidence, from the warmer and low-latitudinal regions. Our discovery of a male Denisovan from Taiwan offers novel insights to reveal this big mystery.

Q2: What are the limitations of the study?

Our study successfully extracted partial ancient proteins but no ancient DNA, which indeed hinders our subsequent analyses and interpretations. Still, this does not affect and diminish the importance of a male Denisovan from Taiwan. On the other hand, this Denisovan discovery provokes our curiosity for more details about Denisovans coming, inhabiting, or leaving Taiwan.

For example, simply think of human evolution from a Taiwan perspective. This male Denisovan represents the oldest known human from Taiwan. Then, when did modern humans come to Taiwan? Did Denisovans and modern humans coexist in Taiwan? Or, did Denisovans go out of Taiwan to Oceania to explore a new world across oceans?

Also, we can think of this discovery from a broader viewpoint, which includes other animals. Another Science paper that we published in 2023 was about island extinctions (including Taiwan). Our analyses also showed that modern humans accelerated the extinctions on islands across the world. Then, how much or did Denisovans contribute to the island extinctions? Our Denisovan discovery, which seems to only include limited data on ancient proteins, has the potential to lead to more interesting and exciting research projects.

The research article titled "A Male Denisovan Mandible from Pleistocene Taiwan" marks a significant advancement in our understanding of Denisovan morphology and geographic distribution. The specimen, known as Penghu 1, was recovered through seabed dredging in the Penghu Channel, situated between the Penghu archipelago and Taiwan, approximately 50 kilometers off Taiwan’s western coast.

Leveraging cutting-edge palaeoproteomic methods, an international research team—including experts from Denmark (Drs. Enrico Cappellini and Frido Welker, University of Copenhagen), Japan (Drs. Takumi Tsutaya, SOKENDAI and Yousuke Kaifu, University of Tokyo), and Taiwan (Drs. Chun-Hsiang Chang, National Museum of Natural Science, and Cheng-Hsiu Tsai, National Taiwan University)—successfully identified the mandible as belonging to a male Denisovan.

This study represents a major methodological breakthrough, as previous attempts to extract ancient DNA from Penghu 1 were unsuccessful, likely due to tropical environmental degradation. Instead, through protein analysis, the researchers retrieved over 4,200 amino acid residues from 51 proteins, including collagen and enamel proteins. Notably, they detected two Denisovan-specific amino acid variants (in AMBN and COL1A2), providing robust molecular evidence of the specimen’s Denisovan identity. This underscores the value of palaeoproteomics in contexts where ancient DNA preservation is poor, particularly in humid and temperate regions.

The discovery significantly expands the known range of Denisovan habitation by thousands of kilometers, aligning with genomic data suggesting that Denisovans were once widespread across eastern Asia and possibly parts of island Southeast Asia. Previously, direct molecular evidence of Denisovans was limited to remains from Denisova Cave in Siberia and the Xiahe site on the Tibetan Plateau. The identification of Penghu 1 in what would have been a lowland and humid Pleistocene environment challenges earlier assumptions that Denisovans were predominantly adapted to cold or high-altitude conditions, suggesting instead a high degree of ecological flexibility.

Morphologically, Penghu 1 exhibits dentognathic traits consistent with other Denisovan fossils, including a robust and low mandibular body, large molars, and thick premolar roots, as well as third molar agenesis. These features are in stark contrast with the tall and gracile mandibles characteristic of Neanderthals, highlighting divergent evolutionary trends within archaic human lineages.

While this study is undoubtedly a breakthrough, due to the limited number of amino acid variation in protein sequences, the Denisovan assignment is supported by only two amino acid variants (in AMBN and COL1A2). This narrow molecular signal limits the ability to discern finer-scale population structure within Denisovans or to distinguish them confidently from potentially related or hybrid lineages.

In sum, the molecular identification of Penghu 1 as a Denisovan provides a vital data point for paleoanthropological research. It confirms the Denisovan presence in subtropical East Asia and offers new insights into their adaptability and morphological variation. Research into ancient human remains—such as the identified Denisovan mandible from Penghu—helps uncover the deep human history of Taiwan. This isn't just about ancient bones; it's about redefining who we are and placing Taiwan more firmly on the map of human evolution. Understanding our ancestral roots enriches our collective identity and helps foster a deeper connection to our cultural and biological heritage.