Historical Thinking and the Human: Introduction

In recent years the age-old question “what is the human?” has acquired a new acuteness and novel dimensions. In introducing the special issue on “Historical Thinking and the Human”, this article argues that there are two main trends behind the contemporary “crisis of human”: ecological transformations (related to human-induced climate change and planetary environmental challenges), and technological ones (including advancements in human enhancement, biotechnology and artificial intelligence). After discussing the respective anthropocenic and technoscientific redefinitions of the human, the paper theorizes three elements in an emerging new historicity of the human: first, the move from a fixed category to a dynamic and indeterminate concept, considering the human as a lifeform in movement; second, the extent to which the human is conceived of in its relational dependence on various non-human agents, organic and non-organic; and third, the reconceptualization of the human not as one but as many, to comprehend that we cannot speak of human individuality in the classical biological sense. In the final part, the article addresses the consequences of the redefinition of the human for historical thinking. It makes the case for the need to elaborate a new notion of history – captured by the phrase “more-than-human history”, and attuned to an emerging planetary regime of historicity in which historical thinking becomes able to affirm multiple temporalities: digital, technoscientific, sociocultural, human, biological and anthropocenic. The article concludes by recognizing the necessity to venture into a new transdisciplinary knowledge economy, appropriate for making sense of the contemporary constellation of the entangled human, technological and natural worlds.

Risk Assessment of SARS-CoV-2 in Antarctic Wildlife

The coronavirus disease 2019 (COVID-19) pandemic, caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has spread rapidly to most parts of the world, causing high numbers of deaths and significant social and economic impacts. SARS-CoV-2 is a novel coronavirus with a suggested zoonotic origin and with the potential for cross-species transmission among animals. Antarctica can be considered the only continent free of SARS-CoV-2 although at the end of the 2019-2020 tourist season, at least one SARS-CoV-2 positive tourist visited the Antarctic Peninsula. Therefore, concerns have been expressed regarding the potential human introduction of this virus to the continent through the activities of research or tourism with potential effects including those related to human health, but also the potential for virus transmission to Antarctic wildlife. This reverse-zoonotic transmission risk to Antarctic wildlife is assessed considering the available information on host susceptibility, dynamics of the infection in humans, and contact interactions between humans and Antarctic wildlife. Measures to reduce the risk are proposed as well as the identification of knowledge gaps related to this issue.

Fire and grazing determined grasslands of central Madagascar represent ancient assemblages

The ecology of Madagascar's grasslands is under-investigated and the dearth of ecological understanding of how disturbance by fire and grazing shapes these grasslands stems from a perception that disturbance shaped Malagasy grasslands only after human arrival. However, worldwide, fire and grazing shape tropical grasslands over ecological and evolutionary timescales, and it is curious Madagascar should be a global anomaly. We examined the functional and community ecology of Madagascar's grasslands across 71 communities in the Central Highlands. Combining multivariate abundance models of community composition and clustering of grass functional traits, we identified distinct grass assemblages each shaped by fire or grazing. The fire-maintained assemblage is primarily composed of tall caespitose species with narrow leaves and low bulk density. By contrast, the grazer-maintained assemblage is characterized by mat-forming, high bulk density grasses with wide leaves. Within each assemblage, levels of endemism, diversity and grass ages support these as ancient assemblages. Grazer-dependent grasses can only have co-evolved with a now-extinct megafauna. Ironically, the human introduction of cattle probably introduced a megafaunal substitute facilitating modern day persistence of a grazer-maintained grass assemblage in an otherwise defaunated landscape, where these landscapes now support the livelihoods of millions of people.

Taxonomy of Micronesian monitors (Reptilia: Squamata: Varanus ): endemic status of new species argues for caution in pursuing eradication plans

In the light of recent phylogenetic studies, we re-assess the taxonomy and biogeography of the Varanus populations distributed in the Micronesian islands of Palau, the Western Carolines and the Marianas. Whether these populations are of natural origin or human introductions has long been contentious, but no study has fully resolved that question. Here, we present molecular and morphological evidence that monitor lizards of the Varanus indicus Group reached both Palau and the Mariana Islands sometime in the late Pleistocene and subsequently differentiated into two separate species endemic to each geographical region. One species is confined to the Mariana Islands, and for these populations, we revalidate the name V. tsukamotoi Kishida, 1929. The other species has a disjunct distribution in Palau, the Western Carolines and Sarigan Island in the Northern Marianas and is herein described as V. bennetti sp. nov. Both species are most closely allied to each other, V. lirungensis and V. rainerguentheri , suggesting that colonization of Micronesia took place from the Moluccas. We discuss the biogeographic distributions of both species in the light of the likely colonization mechanism and previous arguments for human introduction, and we argue that bounties for Palauan populations are ill-advised and plans for eradication of some other populations must first demonstrate that they are, in fact, introduced and not native.

Advances in Understanding Landscape Influences on Freshwater Habitats and Biological Assemblages

<i>Abstract.</i>—Waterfalls, caused by the abrupt changes of elevation in streams, are natural barriers that influence the distribution and dispersion of aquatic species. The resulting habitat fragmentation has contributed to species specialization as well as barriers that inhibit passage of nonnative species upstream. In Hawai‘i, it is assumed that nonnative species are unable to pass waterfall barriers, yet they are present above some waterfalls, possibly facilitated by human introduction. In this study, we used a landscape approach to identify likely human introductions and examine the ability of nonnative stream fauna to bypass waterfalls. We identified the human activities associated with the high likelihood of species introduction. We found that when a local catchment has a population density >4.24 people/km2 or road length density is >0.01 km/km2, the presence of nonnative species in the stream is likely a result of human introduction. After filtering human facilitated introduction, we also assessed the potential waterfall climbing ability of 14 nonnative taxa. We found that 12 out of the 14 taxa were absent upstream of waterfalls, indicative of their inability to traverse waterfalls. Only two species, Tahitian prawn (also known as monkey river shrimp) <i>Macrobrachium lar </i>and American bullfrog <i>Rana catesbiana</i>, seem able to pass waterfalls. This study highlights the role that people play in facilitating species introductions in otherwise inaccessible habitats. Without human interference, waterfalls can be considered effective barriers to nonnative species and can be instrumental in supporting nonnative species eradication and control strategies.

Amphi-Pacific tropical disjunctions in the bryophyte floras of Asia and the New World

Disjunctions between tropical America and tropical Asia, commonly called amphi-Pacific tropical disjunctions, have frequently been discussed among flowering plants but have received very little attention in bryology. A screening of the literature revealed nine species and sixteen genera or infrageneric taxa of bryophytes with amphi-Pacific tropical (or subtropical) ranges. They include Austinia tenuinervis, Diphyscium chiapense, D. longiflorum, Elmerobryum, Fissidens sect. Sarawakia, Ganguleea angulosa, Hydrogonium arcuatum, Hymenostyliella, Hymenostylium aurantiacum, Luisierella barbula, Mniomalia, Rozea, Sphaerotheciella and Sorapilla among the mosses and Ceratolejeunea grandiloba, Drepanolejeunea subg. Rhaphidolejeunea, Lejeunea sect. Echinocolea, Lobatiriccardia, Myriocoleopsis sect. Myriocoleopsis, Phycolepidozia, Pictolejeunea, Rectolejeunea, Southbya organensis and Vitalianthus among liverworts. All of them occur in tropical or subtropical Asia and the Neotropics but are not known from Africa. The causes of the amphi-Pacific tropical disjunctions in bryophytes are still unclear. In flowering plants, molecular analyses indicate that amphi-Pacific tropical ranges frequently resulted from past migration across Eurasia and the northern Atlantic Ocean, followed by local extinction. This scenario may also have operated in amphi-Pacific bryophytes but some might have reached South America via the southern Pacific migration route. The possibility of direct long-range dispersal across the Pacific Ocean cannot be ruled out and this scenario seems likely for Southbya organensis, which occurs on Hawaii and freely produces spores and small gemmae. The possibility that the disjunctive ranges reflect insufficient collecting and that some taxa also occur in Africa should also be taken into account. There is no strong evidence for human introduction of amphi-Pacific tropical bryophytes. The new combinations Lejeunea sect. Echinocolea (R.M.Schust.) Gradst. comb. nov. and Myriocoleopsis sect. Protocolea (R.M.Schust.) Gradst. comb. nov. are proposed.

Mice as stowaways? Colonization history of Danish striped field mice

Species from the steppe region of Eastern Europe likely colonized northwestern Europe in connection with agriculture after 6500 BP. The striped field mouse ( Apodemus agrarius Pallas, 1783), is a steppe-derived species often found in human crops. It is common on the southern Danish islands of Lolland and Falster, which have been isolated from mainland Europe since approximately 10 300–8000 BP. Thus, this species could have been brought in with humans in connection with agriculture, or it could be an earlier natural invader. We sequenced 86 full mitochondrial genomes from the northwestern range of the striped field mouse, analysed phylogenetic relationships and estimated divergence time. The results supported human-induced colonization of Denmark in the Subatlantic or Subboreal period. A newly discovered population from Central Jutland in Denmark diverged from Falster approximately 100–670 years ago, again favouring human introduction. One individual from Sweden turned out to be a recent introduction from Central Jutland.

Oceanic dispersal, vicariance and human introduction shaped the modern distribution of the termites Reticulitermes , Heterotermes and Coptotermes

Reticulitermes , Heterotermes and Coptotermes form a small termite clade with partly overlapping distributions. Although native species occur across all continents, the factors influencing their distribution are poorly known. Here, we reconstructed the historical biogeography of these termites using mitochondrial genomes of species collected on six continents. Our analyses showed that Reticulitermes split from Heterotermes + Coptotermes at 59.5 Ma (49.9–69.5 Ma 95% CI), yet the oldest split within Reticulitermes (Eurasia and North America) is 16.1 Ma (13.4–19.5 Ma) and the oldest split within Heterotermes + Coptotermes is 36.0 Ma (33.9–40.5 Ma). We detected 14 disjunctions between biogeographical realms, all of which occurred within the last 34 Ma, not only after the break-up of Pangaea, but also with the continents in similar to current positions. Land dispersal over land bridges explained four disjunctions, oceanic dispersal by wood rafting explained eight disjunctions, and human introduction was the source of two recent disjunctions. These wood-eating termites, therefore, appear to have acquired their modern worldwide distribution through multiple dispersal processes, with oceanic dispersal and human introduction favoured by the ecological traits of nesting in wood and producing replacement reproductives.