Fostering Responsible Research on Ancient DNA

Informed proxy consent for ancient DNA research

Embracing the underlying principles and processes of informed proxy consent or relational autonomy consent in human ancient DNA research can transform research.

Archaeology meets environmental genomics: implementing sedaDNA in the study of the human past

Sedimentary ancient DNA (sedaDNA) has become one of the standard applications in the field of paleogenomics in recent years. It has been used for paleoenvironmental reconstructions, detecting the presence of prehistoric species in the absence of macro remains and even investigating the evolutionary history of a few species. However, its application in archaeology has been limited and primarily focused on humans. This article argues that sedaDNA holds significant potential in addressing key archaeological questions concerning the origins, lifestyles, and environments of past human populations. Our aim is to facilitate the integration of sedaDNA into the standard workflows in archaeology as a transformative tool, thereby unleashing its full potential for studying the human past. Ultimately, we not only underscore the challenges inherent in the sedaDNA field but also provide a research agenda for essential enhancements needed for implementing sedaDNA into the archaeological workflow.

Follow the citations: Tracing pathways of "race as biology" assumptions in medical algorithms in eGFR and spirometry

Despite overwhelming evidence to the contrary, the concept of 'race' as a biological unit continues to persist in various scientific disciplines, notably in the field of medicine. This paper explores the persistence of 'race as biology' in medical research via examining select citational practices that have perpetuated this problematic concept. Citations serve as a cornerstone in scientific literature, signifying reliability and expert affirmation. By analyzing citation threads and historical patterns, we aim to shed light on the creation and perpetuation of false scientific truths and their impact on medical research, training, and practice. We focus on two prominent examples, eGFR and Spirometry, and trace key articles' citational histories, highlighting the flawed evidence in support of racial corrections in medical assessments. The eGFR equation incorporates 'race' as a factor based on the erroneous belief that Black individuals have higher muscle mass than white individuals. Our analysis reveals that key cited sources for this belief lack robust and well-developed datasets. Similarly, Spirometry measurements incorporate racial correction factors, relying on questionable evidence dating back to the Civil War era. Citations serve as a cornerstone in scientific literature, signifying reliability and expert affirmation. They play a crucial role in shaping theoretical positions and validating data and assumed knowledge. Evaluating citation threads and key articles consistently referenced over time can reveal how falsehoods and erroneous assertions are constructed and maintained in scientific fields. This study underscores the need for critical examination of citational practices in medical research and urges a shift toward a more cautious approach when citing sources that support 'race as biology.' The paper calls for a reevaluation of pedagogical approaches and assigned readings in medical education to prioritize an anti-racist perspective in future research endeavors.

Exploring the dimensions of responsible research systems and cultures: a scoping review

The responsible conduct of research is foundational to the production of valid and trustworthy research. Despite this, our grasp of what dimensions responsible conduct of research (RCR) might contain-and how it differs across disciplines (i.e. how it is conceptualized and operationalized)-is tenuous. Moreover, many initiatives related to developing and maintaining RCR are developed within disciplinary and institutional silos which naturally limits the benefits that RCR practice can have. To this end, we are working to develop a better understanding of how RCR is conceived and realized, both across disciplines and across institutions in Europe. The first step in doing this is to scope existing knowledge on the topic, of which this scoping review is a part. We searched several electronic databases for relevant published and grey literature. An initial sample of 715 articles was identified, with 75 articles included in the final sample for qualitative analysis. We find several dimensions of RCR that are underemphasized or are excluded from the well-established World Conferences on Research Integrity (WCRI) Singapore Statement on Research Integrity and explore facets of these dimensions that find special relevance in a range of research disciplines.

Uncovering the Holocene roots of contemporary disease-scapes: bringing archaeology into One Health

The accelerating pace of emerging zoonotic diseases in the twenty-first century has motivated cross-disciplinary collaboration on One Health approaches, combining microbiology, veterinary and environmental sciences, and epidemiology for outbreak prevention and mitigation. Such outbreaks are often caused by spillovers attributed to human activities that encroach on wildlife habitats and ecosystems, such as land use change, industrialized food production, urbanization and animal trade. While the origin of anthropogenic effects on animal ecology and biogeography can be traced to the Late Pleistocene, the archaeological record-a long-term archive of human-animal-environmental interactions-has largely been untapped in these One Health approaches, thus limiting our understanding of these dynamics over time. In this review, we examine how humans, as niche constructors, have facilitated new host species and 'disease-scapes' from the Late Pleistocene to the Anthropocene, by viewing zooarchaeological, bioarchaeological and palaeoecological data with a One Health perspective. We also highlight how new biomolecular tools and advances in the '-omics' can be holistically coupled with archaeological and palaeoecological reconstructions in the service of studying zoonotic disease emergence and re-emergence.

Specimens as individuals: Four interventions and recommendations for great ape skeletal collections research and curation

Extensive discourse surrounds the ethics of human skeletal research and curation, but there has yet to be a similar discussion of the treatment of great ape skeletal remains, despite the clear interest in their ethical treatment when alive. Here we trace the history of apes who were killed and collected for natural history museums during the early 20th century and showcase how the guiding research questions of the colonial era continue to influence scholarship. We discuss best practices for improving industry and academic standards of research on, and the curation of, ape remains. The suggested interventions involve restoring individual identity and narrative to great apes while engaging with contextual reflexivity and decolonial theory. The resulting recommendations include contextualizing the individual, piecing individuals back together, challenging/questioning the captive-wild dichotomy, and collaborative international conversations. Our objective is to encourage a conversation regarding ethical and theoretical considerations in great ape skeletal remains research.

Review: Computational analysis of human skeletal remains in ancient DNA and forensic genetics

Degraded DNA is used to answer questions in the fields of ancient DNA (aDNA) and forensic genetics. While aDNA studies typically center around human evolution and past history, and forensic genetics is often more concerned with identifying a specific individual, scientists in both fields face similar challenges. The overlap in source material has prompted periodic discussions and studies on the advantages of collaboration between fields toward mutually beneficial methodological advancements. However, most have been centered around wet laboratory methods (sampling, DNA extraction, library preparation, etc.). In this review, we focus on the computational side of the analytical workflow. We discuss limitations and considerations to consider when working with degraded DNA. We hope this review provides a framework to researchers new to computational workflows for how to think about analyzing highly degraded DNA and prompts an increase of collaboration between the forensic genetics and aDNA fields.

Towards an ethical and legal framework in archeogenomics: A local case in the Atlantic coast of central Patagonia

Ethical discussions around ancient DNA (aDNA) research predate the technological breakthroughs that led to the accelerated generation of ancient genomic data, revealing a long-due need to address these aspects in the field. Given the diverse conflicts that genomics has raised towards the communities associated with the Non-living Human Ancestors under study, it has been suggested that the ethical and legal implications of genetically studying present-day and ancient human populations should be considered case-by-case. Nevertheless, the discussions have focused on US and European perspectives. To contribute from a local and Latin American position to the problem, we present the history of consensus and disagreement of the relationships between scientists and Indigenous communities of the Atlantic coast of the central Argentinian Patagonia. We describe how these relationships resulted in the approval of a groundbreaking provincial law that acknowledges the Indigenous community's right to be involved in decision-making concerning their Ancestors. In addition, we emphasize how these established relationships allowed the development of aDNA studies. With this background, we address the main ethical concerns of genomic studies of Ancestors identified in the reference literature and commit to applying some of the recommendations suggested in those ethical guidelines. Then, we reflect on possible negative consequences of ongoing research and propose some suggestions based on personal experiences that will contribute to moving the ethical field towards a more contextualized science with a local perspective.

A Glimpse into the Past: What Ancient Viral Genomes Reveal About Human History

Humans have battled viruses for millennia. However, directly linking the symptomatology of disease outbreaks to specific viral pathogens was not possible until the twentieth century. With the advent of the genomic era and the development of advanced protocols for isolation, sequencing, and analysis of ancient nucleic acids from diverse human remains, the identification and characterization of ancient viruses became feasible. Recent studies have provided invaluable information about past epidemics and made it possible to examine assumptions and inferences on the origin and evolution of certain viral families. In parallel, the study of ancient viruses also uncovered their importance in the evolution of the human lineage and their key roles in shaping major events in human history. In this review, we describe the strategies used for the study of ancient viruses, along with their limitations, and provide a detailed account of what past viral infections have revealed about human history.

Ethical considerations when co-analyzing ancient DNA and data from private genetic databases

Ancient DNA studies have begun to explore the possibility of identifying identical DNA segments shared between historical and living people. This research requires access to large genetic datasets to maximize the likelihood of identifying previously unknown, close genetic connections. Direct-to-consumer genetic testing companies, such as 23andMe, Inc., manage by far the largest and most diverse genetic databases that can be used for this purpose. It is therefore important to think carefully about guidelines for carrying out collaborations between researchers and such companies. Such collaborations require consideration of ethical issues, including policies for sharing ancient DNA datasets, and ensuring reproducibility of research findings when access to privately controlled genetic datasets is limited. At the same time, they introduce unique possibilities for returning results to the research participants whose data are analyzed, including those who are identified as close genetic relatives of historical individuals, thereby enabling ancient DNA research to contribute to the restoration of information about ancestral connections that were lost over time, which can be particularly meaningful for families and groups where such history has not been well documented. We explore these issues by describing our experience designing and carrying out a study searching for genetic connections between 18th- and 19th-century enslaved and free African Americans who labored at Catoctin Furnace, Maryland, and 23andMe research participants. We share our experience in the hope of helping future researchers navigate similar ethical considerations, recognizing that our perspective is part of a larger conversation about best ethical practices.

The genetic legacy of African Americans from Catoctin Furnace

Few African Americans have been able to trace family lineages back to ancestors who died before the 1870 United States Census, the first in which all Black people were listed by name. We analyzed 27 individuals from Maryland's Catoctin Furnace African American Cemetery (1774-1850), identifying 41,799 genetic relatives among consenting research participants in 23andMe, Inc.'s genetic database. One of the highest concentrations of close relatives is in Maryland, suggesting that descendants of the Catoctin individuals remain in the area. We find that many of the Catoctin individuals derived African ancestry from the Wolof or Kongo groups and European ancestry from Great Britain and Ireland. This study demonstrates the power of joint analysis of historical DNA and large datasets generated through direct-to-consumer ancestry testing.

Deconstructing Eurocentrism in skin pigmentation research via the incorporation of diverse populations and theoretical perspectives

The evolution of skin pigmentation has been shaped by numerous biological and cultural shifts throughout human history. Vitamin D is considered a driver of depigmentation evolution in humans, given the deleterious health effects associated with vitamin D deficiency, which is often shaped by cultural factors. New advancements in genomics and epigenomics have opened the door to a deeper exploration of skin pigmentation evolution in both contemporary and ancient populations. Data from ancient Europeans has offered great context to the spread of depigmentation alleles via the evaluation of migration events and cultural shifts that occurred during the Neolithic. However, novel insights can further be gained via the inclusion of diverse ancient and contemporary populations. Here we present on how potential biases and limitations in skin pigmentation research can be overcome with the integration of interdisciplinary data that includes both cultural and biological elements, which have shaped the evolutionary history of skin pigmentation in humans.

Natural products from reconstructed bacterial genomes of the Middle and Upper Paleolithic

Major advances over the past decade in the field of ancient DNA are providing access to past paleogenomic diversity, but the diverse functions and biosynthetic capabilities of this growing paleome remain largely elusive. Here, we investigated the dental calculus of 12 Neanderthals and 52 anatomically modern humans spanning 100 kya to the present and reconstructed 459 bacterial metagenome-assembled genomes (MAGs). We identified a biosynthetic gene cluster (BGC) shared by seven Middle and Upper Paleolithic individuals that allows for the heterologous production of a class of previously unknown metabolites we name paleofurans. This paleobiotechnological approach demonstrates that viable biosynthetic machinery can be produced from the preserved genetic material of ancient organisms, allowing access to natural products from the Pleistocene and providing a promising area for natural product exploration.

Facing Our History-Building an Equitable Future

This report is the product of a major year-long initiative to acknowledge and reckon with past injustice, as well as progress toward justice, within the American Society of Human Genetics (ASHG) and the broader field of human genetics. Approved by the ASHG Board of Directors and launched in 2021, the initiative was sparked by the social and racial reckonings in 2020. The ASHG Bboard of Directors asked ASHG to acknowledge and provide examples of how human genetics theories and knowledge "have been used to feed and justify racism, eugenics, and other systemic forms of injustice, and to focus specifically on examples of ASHG's role in fostering or failing to rebuke harms and on steps the Society could take to address findings." The initiative was undertaken with support and input from an expert panel of human geneticists, historians, clinician-scientists, equity scholars, and social scientists and included a research and environmental scan, four expert panel meetings, and a community dialogue as its main activities.

From collected stamps to hair locks: ethical and legal implications of testing DNA found on privately owned family artifacts

Biological samples containing DNA that is attributed to deceased relatives, can now undergo genetic testing at a reasonable cost due to revolutionary improvements in sampling, sequencing, and analytical techniques. This artifact DNA testing, or 'artDNA', includes genetic analysis of hair locks, stamps, envelopes with saliva traces or teeth. ArtDNA can reveal valuable information about a deceased relative or one's genetic background, but it also presents novel ethical dilemmas and legal uncertainties for genetic researchers and commercial testing services. In this paper, we provide an analysis of some of the unique ethical and legal risks of such testing and provide needed recommendations for practitioners of private family artDNA testing. ArtDNA testing generates ethical and legal risks regarding the privacy and autonomy of deceased individuals, the rights of living relatives over their ancestor's genetic information, and the rights of living persons to control their own genetic information. To mitigate these risks, practitioners can conduct certain preliminary testing to ascertain the identity of a DNA donor and estimate the time that has elapsed postmortem. Generally, the ethical and legal concerns will be higher when a shorter period has passed between the death of the DNA donor and the time of artifact DNA testing. Regardless, all artDNA testing present some risks, and practitioners should exercise professional judgement as necessary.

Extracting the practices of paleogenomics: A study of ancient DNA labs and research in relation to Native Americans and Indigenous peoples

OBJECTIVES

The field of paleogenomics has rapidly grown, influencing a range of scientific fields and drawing notice from the public. In the United States, this work is especially salient for Native Americans, who are frequently the subject of ancient DNA analyses, but are less frequently included as researchers, collaborators, or advisors. This article seeks to deepen our understanding of the current state of paleogenomics so that the field can center Indigenous peoples and their experiences, knowledges, and stakes in the research process.

MATERIALS AND METHODS

We conducted 31 semi-structured interviews with researchers from three paleogenomics labs located in North America and Europe. We used a responsive interviewing technique where the interview resembled a conversation around a set of questions that could change depending upon the interviewee's answers and experiences. We then employed a theme-based analysis of the interviews.

RESULTS

Through this analysis, we are able to identify practices in the field related to training, the structuring of labs and projects, consent, data control, Ancestor care, and funding that influence various forms of engagement with Indigenous peoples, and which foster or delimit ethical commitments to descendant communities.

DISCUSSION

This research not only elucidates contemporary practices in paleogenomics labs but also identifies specific areas of potential intervention to help researchers work toward ethical and collaborative paleogenomic research with Indigenous peoples. Using these results, researchers and community advocates can work toward reorienting the field of paleogenomics toward ethical research with Indigenous peoples.

Advancements and Challenges in Ancient DNA Research: Bridging the Global North-South Divide

Ancient DNA (aDNA) research first began in 1984 and ever since has greatly expanded our understanding of evolution and migration. Today, aDNA analysis is used to solve various puzzles about the origin of mankind, migration patterns, and the spread of infectious diseases. The incredible findings ranging from identifying the new branches within the human family to studying the genomes of extinct flora and fauna have caught the world by surprise in recent times. However, a closer look at these published results points out a clear Global North and Global South divide. Therefore, through this research, we aim to emphasize encouraging better collaborative opportunities and technology transfer to support researchers in the Global South. Further, the present research also focuses on expanding the scope of the ongoing conversation in the field of aDNA by reporting relevant literature published around the world and discussing the advancements and challenges in the field.

Community partnerships are fundamental to ethical ancient DNA research

The ethics of the scientific study of Ancestors has long been debated by archaeologists, bioanthropologists, and, more recently, ancient DNA (aDNA) researchers. This article responds to the article "Ethics of DNA research on human remains: five globally applicable guidelines" published in 2021 in Nature by a large group of aDNA researchers and collaborators. We argue that these guidelines do not sufficiently consider the interests of community stakeholders, including descendant communities and communities with potential, but yet unestablished, ties to Ancestors. We focus on three main areas of concern with the guidelines. First is the false separation of "scientific" and "community" concerns and the consistent privileging of researcher perspectives over those of community members. Second, the commitment of the guidelines' authors to open data ignores the principles and practice of Indigenous Data Sovereignty. Further, the authors argue that involving community members in decisions about publication and data sharing is unethical. We argue that excluding community perspectives on "ethical" grounds is convenient for researchers, but it is not, in fact, ethical. Third, we stress the risks of not consulting communities that have established or potential ties to Ancestors, using two recent examples from the literature. Ancient DNA researchers cannot focus on the lowest common denominator of research practice, the bare minimum that is legally necessary. Instead, they should be leading multidisciplinary efforts to create processes to ensure communities from all regions of the globe are identified and engaged in research that affects them. This will often present challenges, but we see these challenges as part of the research, rather than a distraction from the scientific endeavor. If a research team does not have the capacity to meaningfully engage communities, questions must be asked about the value and benefit of their research.

Twenty-first century bioarchaeology: Taking stock and moving forward

This article presents outcomes from a Workshop entitled "Bioarchaeology: Taking Stock and Moving Forward," which was held at Arizona State University (ASU) on March 6-8, 2020. Funded by the National Science Foundation (NSF), the School of Human Evolution and Social Change (ASU), and the Center for Bioarchaeological Research (CBR, ASU), the Workshop's overall goal was to explore reasons why research proposals submitted by bioarchaeologists, both graduate students and established scholars, fared disproportionately poorly within recent NSF Anthropology Program competitions and to offer advice for increasing success. Therefore, this Workshop comprised 43 international scholars and four advanced graduate students with a history of successful grant acquisition, primarily from the United States. Ultimately, we focused on two related aims: (1) best practices for improving research designs and training and (2) evaluating topics of contemporary significance that reverberate through history and beyond as promising trajectories for bioarchaeological research. Among the former were contextual grounding, research question/hypothesis generation, statistical procedures appropriate for small samples and mixed qualitative/quantitative data, the salience of Bayesian methods, and training program content. Topical foci included ethics, social inequality, identity (including intersectionality), climate change, migration, violence, epidemic disease, adaptability/plasticity, the osteological paradox, and the developmental origins of health and disease. Given the profound changes required globally to address decolonization in the 21st century, this concern also entered many formal and informal discussions.

LGBTQ+ Perspectives on Conducting Genomic Research on Sexual Orientation and Gender Identity

We conducted in-depth, semi-structured interviews with LGBTQ+-identified individuals (n = 31) to explore the range of LGBTQ+ perspectives on genomic research using either sexual orientation or gender identity (SOGI) data. Most interviewees presumed that research would confirm genetic contributions to sexual orientation and gender identity. Primary hopes for such confirmation included validating LGBTQ+ identities, improved access to and quality of healthcare and other resources, and increased acceptance in familial, socio-cultural, and political environments. Areas of concern included threats of pathologizing and medicalizing LGBTQ+ identities and experiences, undermining reproductive rights, gatekeeping of health or social systems, and malicious testing or misuse of genetic results, particularly for LGBTQ+ youth. Overall, interviewees were divided on the acceptability of genomic research investigating genetic contributions to sexual orientation and gender identity. Participants emphasized researchers' ethical obligations to LGBTQ+ individuals and endorsed engagement with LGBTQ+ communities throughout all aspects of genomic research using SOGI data.

Recommendations for Sustainable Ancient DNA Research in the Global South: Voices From a New Generation of Paleogenomicists

Paleogenomics - the study of ancient genomes - has made significant contributions, especially to our understanding of the evolutionary history of humans. This knowledge influx has been a direct result of the coupling of next-generation sequencing with improved methods for DNA recovery and analysis of ancient samples. The appeal of ancient DNA studies in the popular media coupled with the trend for such work to be published in “high impact” journals has driven the amassing of ancestral human remains from global collections, often with limited to no engagement or involvement of local researchers and communities. This practice in the paleogenomics literature has led to limited representation of researchers from the Global South at the research design and subsequent stages. Additionally, Indigenous and descendant communities are often alienated from popular and academic narratives that both involve and impact them, sometimes adversely. While some countries have safeguards against ‘helicopter science’, such as federally regulated measures to protect their biocultural heritage, there is variable oversight in others with regard to sampling and exportation of human remains for destructive research, and differing requirements for accountability or consultation with local researchers and communities. These disparities reveal stark contrasts and gaps in regional policies that lend themselves to persistent colonial practices. While essential critiques and conversations in this sphere are taking place, these are primarily guided through the lens of US-based heritage legislation such as the Native American Graves and Protection Act (NAGPRA). In this article, we aim to expand the scope of ongoing conversations by taking into account diverse regional contexts and challenges drawing from our own research experiences in the field of paleogenomics. We emphasize that true collaborations involve knowledge sharing, capacity building, mutual respect, and equitable participation, all of which take time and the implementation of sustainable research methods; amass-and-publish strategy is simply incompatible with this ethos.

Ethical Guidance in Human Paleogenomics: New and Ongoing Perspectives

Over the past two decades, the study of ancient genomes from Ancestral humans, or human paleogenomic research, has expanded rapidly in both scale and scope. Ethical discourse has subsequently emerged to address issues of social responsibility and scientific robusticity in conducting research. Here, we highlight and contextualize the primary sources of professional ethical guidance aimed at paleogenomic researchers. We describe the tension among existing guidelines, while addressing core issues such as consent, destructive research methods, and data access and management. Currently, there is a dissonance between guidelines that focus on scientific outcomes and those that hold scientists accountable to stakeholder communities, such as descendants. Thus, we provide additional tools to navigate the complexities of ancient DNA research while centering engagement with stakeholder communities in the scientific process. Expected final online publication date for the Annual Review of Genomics and Human Genetics, Volume 23 is October 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Epigenomic Modifications in Modern and Ancient Genomes

Epigenetic changes have been identified as a major driver of fundamental metabolic pathways. More specifically, the importance of epigenetic regulatory mechanisms for biological processes like speciation and embryogenesis has been well documented and revealed the direct link between epigenetic modifications and various diseases. In this review, we focus on epigenetic changes in animals with special attention on human DNA methylation utilizing ancient and modern genomes. Acknowledging the latest developments in ancient DNA research, we further discuss paleoepigenomic approaches as the only means to infer epigenetic changes in the past. Investigating genome-wide methylation patterns of ancient humans may ultimately yield in a more comprehensive understanding of how our ancestors have adapted to the changing environment, and modified their lifestyles accordingly. We discuss the difficulties of working with ancient DNA in particular utilizing paleoepigenomic approaches, and assess new paleoepigenomic data, which might be helpful in future studies.

A call for unity in DEIJ efforts using a proposed framework for education, Recruitment, Retainment, Research, and Active outreach (ERA) for genetic counselors in the United States

Genetic counselors, like many other healthcare providers, play a vital role in genomic health care. As a profession, we, along with our colleagues and students, have recognized the need to improve and incorporate diversity, equity, inclusion, and justice (DEIJ) within our daily ways of practice to help create access to genomic technologies. In order to create systemic change and focus on unity, open communication, and transparency, we introduce a suggested framework called ERA (Education, Recruitment, Retainment, Research, and Active Outreach). This framework would benefit a genetic counselor throughout various stages of their career, from student to practicing genetic counselor, and can be broadly applied to all specialties of genomic medicine. Different iterations of DEIJ efforts have arisen in the National Society of Genetic Counselors (NSGC), from the D&I (Diversity and Inclusion) Task Force to the J.E.D.I (justice, equity, diversity, and inclusion) committee. The lack of recorded history of these previous efforts and the lack of communication between current DEIJ organizations is one of the many reasons the ERA framework demands unity and transparency to achieve sustainable positive change. Genetic counselors must unite and work collaboratively to conduct and promote DEIJ efforts, so the benefits of genomic medicine can be realized by all.

Ancient human genomes and environmental DNA from the cement attaching 2,000 year-old head lice nits

Over the past few decades, there has been a growing demand for genome analysis of ancient human remains. Destructive sampling is increasingly difficult to obtain for ethical reasons, and standard methods of breaking the skull to access the petrous bone or sampling remaining teeth are often forbidden for curatorial reasons. However, most ancient humans carried head lice and their eggs abound in historical hair specimens. Here we show that host DNA is protected by the cement that glues head lice nits to the hair of ancient Argentinian mummies, 1,500–2,000 years old. The genetic affinities deciphered from genome-wide analyses of this DNA inform that this population migrated from north-west Amazonia to the Andes of central-west Argentina; a result confirmed using the mitochondria of the host lice. The cement preserves ancient environmental DNA of the skin, including the earliest recorded case of Merkel cell polyomavirus. We found that the percentage of human DNA obtained from nit cement equals human DNA obtained from the tooth, yield 2-fold compared with a petrous bone, and 4-fold to a bloodmeal of adult lice a millennium younger. In metric studies of sheaths, the length of the cement negatively correlates with the age of the specimens, whereas hair linear distance between nit and scalp informs about the environmental conditions at the time before death. Ectoparasitic lice sheaths can offer an alternative, nondestructive source of high-quality ancient DNA from a variety of host taxa where bones and teeth are not available and reveal complementary details of their history.

Ancient Metagenomic Studies: Considerations for the Wider Scientific Community

Like modern metagenomics, ancient metagenomics is a highly data-rich discipline, with the added challenge that the DNA of interest is degraded and, depending on the sample type, in low abundance. This requires the application of specialized measures during molecular experiments and computational analyses. Furthermore, researchers often work with finite sample sizes, which impedes optimal experimental design and control of confounding factors, and with ethically sensitive samples necessitating the consideration of additional guidelines. In September 2020, early career researchers in the field of ancient metagenomics met (Standards, Precautions & Advances in Ancient Metagenomics 2 [SPAAM2] community meeting) to discuss the state of the field and how to address current challenges. Here, in an effort to bridge the gap between ancient and modern metagenomics, we highlight and reflect upon some common misconceptions, provide a brief overview of the challenges in our field, and point toward useful resources for potential reviewers and newcomers to the field.

Ethics of DNA research on human remains: five globally applicable guidelines

We are a group of archaeologists, anthropologists, curators and geneticists representing diverse global communities and 31 countries. All of us met in a virtual workshop dedicated to ethics in ancient DNA research held in November 2020. There was widespread agreement that globally applicable ethical guidelines are needed, but that recent recommendations grounded in discussion about research on human remains from North America are not always generalizable worldwide. Here we propose the following globally applicable guidelines, taking into consideration diverse contexts. These hold that: (1) researchers must ensure that all regulations were followed in the places where they work and from which the human remains derived; (2) researchers must prepare a detailed plan prior to beginning any study; (3) researchers must minimize damage to human remains; (4) researchers must ensure that data are made available following publication to allow critical re-examination of scientific findings; and (5) researchers must engage with other stakeholders from the beginning of a study and ensure respect and sensitivity to stakeholder perspectives. We commit to adhering to these guidelines and expect they will promote a high ethical standard in DNA research on human remains going forward.

A Standardized Approach for Shotgun Metagenomic Analysis of Ancient Dental Calculus

Ancient dental calculus provides a challenging, yet unparalleled, opportunity to reconstruct ancient oral microbial communities and trace the origins of modern microbiota-associated diseases. Metagenomic analysis of ancient dental calculus using high-throughput DNA sequencing has proven itself as an effective method to accurately reconstruct microorganisms that once lived in the mouths of ancient humans. Here, we provide the strategy, methodologies, and approaches used to establish an ancient dental calculus project, from project conception, community engagement, sampling, extracting DNA, and preparing shotgun metagenomic DNA libraries for sequencing on an Illumina platform. We also discuss techniques to minimize background or contaminant DNA by monitoring and reducing contamination in calculus data sets, utilizing appropriate protective gear, and employing the use of sample decontamination strategies. In this methodology chapter, we hope to promote transparency in the ancient dental calculus research field and encourage collaboration across the ancient DNA research community.

Considerations for Cardiovascular Genetic and Genomic Research With Marginalized Racial and Ethnic Groups and Indigenous Peoples: A Scientific Statement From the American Heart Association

Historically marginalized racial and ethnic groups and Indigenous peoples are burdened by significant health inequities that are compounded by their underrepresentation in genetic and genomic research. Of all genome-wide association study participants, ≈79% are of European descent, despite this group constituting only 16% of the global population. For underrepresented populations, polygenic risk scores derived from these studies are less accurate in predicting disease phenotypes, novel population-specific genetic variations may be misclassified as potentially pathogenic, and there is a lack of understanding of how different populations metabolize drugs. Although inclusion of marginalized racial and ethnic groups and Indigenous peoples in genetic and genomic research is crucial, scientific studies must be guided by ethical principles of respect, honesty, justice, reciprocity, and care for individuals and communities. Special considerations are needed to support research that benefits the scientific community as well as Indigenous peoples and marginalized groups. Before a project begins, collaboration with community leaders and agencies can lead to successful implementation of the study. Throughout the study, consideration must be given to issues such as implications of informed consent for individuals and communities, dissemination of findings through scientific and community avenues, and implications of community identity for data governance and sharing. Attention to these issues is critical, given historical harms in biomedical research that marginalized groups and Indigenous peoples have suffered. Conducting genetic and genomic research in partnership with Indigenous peoples and marginalized groups guided by ethical principles provides a pathway for scientific advances that will enhance prevention and treatment of cardiovascular disease for everyone.

Peopling of the Americas as inferred from ancient genomics

In less than a decade, analyses of ancient genomes have transformed our understanding of the Indigenous peopling and population history of the Americas. These studies have shown that this history, which began in the late Pleistocene epoch and continued episodically into the Holocene epoch, was far more complex than previously thought. It is now evident that the initial dispersal involved the movement from northeast Asia of distinct and previously unknown populations, including some for whom there are no currently known descendants. The first peoples, once south of the continental ice sheets, spread widely, expanded rapidly and branched into multiple populations. Their descendants-over the next fifteen millennia-experienced varying degrees of isolation, admixture, continuity and replacement, and their genomes help to illuminate the relationships among major subgroups of Native American populations. Notably, all ancient individuals in the Americas, save for later-arriving Arctic peoples, are more closely related to contemporary Indigenous American individuals than to any other population elsewhere, which challenges the claim-which is based on anatomical evidence-that there was an early, non-Native American population in the Americas. Here we review the patterns revealed by ancient genomics that help to shed light on the past peoples who created the archaeological landscape, and together lead to deeper insights into the population and cultural history of the Americas.

Autosomal recessive diseases among the Athabaskans of the southwestern United States: anthropological, medical, and scientific aspects

The peopling of the Americas by Native Americans occurred in 4 waves of which the last was Nadene language speakers of whom Athabaskans are the largest group. As the Europeans were entering the Southwestern states of the USA, Athabaskan hunting-gathering tribes were migrating South from Canada along the Rocky Mountains and undergoing potential bottlenecks reflected in autosomal recessive diseases shared by Apaches and Navajos. About 300 years ago, the Navajo developing a sedentary culture learned from Pueblo Indians while the Apache remained hunter-gathers. Although most of the tribe was rounded up and forced to relocate to Bosque Redondo, the adult breeding population was large enough to prevent a genetic bottleneck. However, some Navajo underwent further population bottlenecks while hiding from the brutal US Army action (under Kit Carson’s guidance). This led to an increased frequency of other autosomal recessive diseases. Recent advances in population genetics, pathophysiology of the diseases, and social/ethical issues concerning their study are reviewed.

Community-curated and standardised metadata of published ancient metagenomic samples with AncientMetagenomeDir

Ancient DNA and RNA are valuable data sources for a wide range of disciplines. Within the field of ancient metagenomics, the number of published genetic datasets has risen dramatically in recent years, and tracking this data for reuse is particularly important for large-scale ecological and evolutionary studies of individual taxa and communities of both microbes and eukaryotes. AncientMetagenomeDir (archived at 10.5281/zenodo.3980833) is a collection of annotated metagenomic sample lists derived from published studies that provide basic, standardised metadata and accession numbers to allow rapid data retrieval from online repositories. These tables are community-curated and span multiple sub-disciplines to ensure adequate breadth and consensus in metadata definitions, as well as longevity of the database. Internal guidelines and automated checks facilitate compatibility with established sequence-read archives and term-ontologies, and ensure consistency and interoperability for future meta-analyses. This collection will also assist in standardising metadata reporting for future ancient metagenomic studies.

Measurement(s)	genome • Metagenome • Metadata • Ancient DNA
Technology Type(s)	digital curation
Factor Type(s)	geographic location • sample age

Machine-accessible metadata file describing the reported data: 10.6084/m9.figshare.13241537