Micro Methods for Megafauna: Novel Approaches to Late Quaternary Extinctions and Their Contributions to Faunal Conservation in the Anthropocene

Leveraging palaeoproteomics to address conservation and restoration agendas

Archaeological and paleontological records offer tremendous yet often untapped potential for examining long-term biodiversity trends and the impact of climate change and human activity on ecosystems. Yet, zooarchaeological and fossil remains suffer various limitations, including that they are often highly fragmented and morphologically unidentifiable, preventing them from being optimally leveraged for addressing fundamental research questions in archaeology, paleontology, and conservation paleobiology. Here, we explore the potential of palaeoproteomics—the study of ancient proteins—to serve as a critical tool for creating richer, more informative datasets about biodiversity change that can be leveraged to generate more realistic, constructive, and effective conservation and restoration strategies into the future.

Collapse of the mammoth-steppe in central Yukon as revealed by ancient environmental DNA

The temporal and spatial coarseness of megafaunal fossil records complicates attempts to to disentangle the relative impacts of climate change, ecosystem restructuring, and human activities associated with the Late Quaternary extinctions. Advances in the extraction and identification of ancient DNA that was shed into the environment and preserved for millennia in sediment now provides a way to augment discontinuous palaeontological assemblages. Here, we present a 30,000-year sedimentary ancient DNA (sedaDNA) record derived from loessal permafrost silts in the Klondike region of Yukon, Canada. We observe a substantial turnover in ecosystem composition between 13,500 and 10,000 calendar years ago with the rise of woody shrubs and the disappearance of the mammoth-steppe (steppe-tundra) ecosystem. We also identify a lingering signal of Equus sp. (North American horse) and Mammuthus primigenius (woolly mammoth) at multiple sites persisting thousands of years after their supposed extinction from the fossil record.

Brutish Neanderthals: History of a merciless characterization

The idea that Neanderthals were brutish and unintelligent is often traced back to Marcellin Boule, a French paleontologist who examined the specimen known as the Old Man in the first decades of the 20th century. This article examines the work of Boule's predecessors and aggregate a variety of literature to underline an argument that this idea has much earlier origins and is rooted in the first recognized specimen discovered in the Neander Valley in 1856. Reorienting our understanding of the brutish Neanderthal to account for its 19th-century origins, allows for a reexamination of the factors in 19th-century culture, science, and society which contributed to this caricature, especially the concepts of race and species' extinction. Such a reexamination dismantles the narrative of Boule's error while providing a new vantage point to think about Neanderthals in the present.

Bone need not remain an elephant in the room for radiocarbon dating

Radiocarbon (¹⁴C) analysis of skeletal remains by accelerator mass spectrometry is an essential tool in multiple branches of science. However, bone ¹⁴C dating results can be inconsistent and not comparable due to disparate laboratory pretreatment protocols that remove contamination. And, pretreatments are rarely discussed or reported by end-users, making it an 'elephant in the room' for Quaternary scientists. Through a questionnaire survey, I quantified consensus on the reliability of collagen pretreatments for ¹⁴C dating across 132 experts (25 countries). I discovered that while more than 95% of the audience was wary of contamination and would avoid gelatinization alone (minimum pretreatment used by most ¹⁴C facilities), 52% asked laboratories to choose the pretreatment method for them, and 58% could not rank the reliability of at least one pretreatment. Ultrafiltration was highly popular, and purification by XAD resins seemed restricted to American researchers. Isolating and dating the amino acid hydroxyproline was perceived as the most reliable pretreatment, but is expensive, time-consuming and not widely available. Solid evidence supports that only molecular-level dating accommodates all known bone contaminants and guarantees complete removal of humic and fulvic acids and conservation substances, with three key areas of progress: (i) innovation and more funded research is required to develop affordable analytical chemistry that can handle low-mass samples of collagen amino acids, (ii) a certification agency overseeing dating-quality control is needed to enhance methodological reproducibility and dating accuracy among laboratories, and (iii) more cross-disciplinary work with better ¹⁴C reporting etiquette will promote the integration of ¹⁴C dating across disciplines. Those developments could conclude long-standing debates based on low-accuracy data used to build chronologies for animal domestications, human/megafauna extirpations and migrations, archaeology, palaeoecology, palaeontology and palaeoclimate models.