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Background Vision is a crucial sense for the evolutionary success of many animal groups. Here we explore the diversity of visual pigments (opsins) in the transcriptomes of amphipods (Crustacea: Amphipoda) and conclude that it is restricted to middle (MWS) and long wavelength-sensitive (LWS) opsins in the overwhelming majority of examined species. Results We evidenced (i) parallel loss of MWS opsin expression in multiple species (including two independently evolved lineages from the deep and ancient Lake Baikal) and (ii) LWS opsin amplification (up to five transcripts) in both Baikal lineages. The number of LWS opsins negatively correlated with habitat depth in Baikal amphipods. Some LWS opsins in Baikal amphipods contained MWS-like substitutions, suggesting that they might have undergone spectral tuning. Conclusions This repeating two-step evolutionary scenario suggests common triggers, possibly the lack of light during the periods when Baikal was permanently covered with thick ice and its subsequent melting. Overall, this observation demonstrates the possibility of revealing climate history by following the evolutionary changes in protein families.

Ionizing radiation is among the most important planetary factors that regulate the intensity and dynamics of biospheric processes. At the early stages of life on the Earth, short-wave radiation permeated the Earth surface. The evolution of the planet, corrected by fluctuations of cosmophysical factors, contributed to the development of the adaptation processes in the emerging biosystems, including resistance to a wide range of ionizing effects. Studies of microorganisms from extreme habitats have changed the scientific paradigm of cell viability and adaptive potential. The taxonomic spectrum of bacteria and archaea, isolated from extreme biotopes and resistant to ionizing radiation, is constantly enlarged. However, it is also necessary to develop in situ studies at the system level, as well as to assess the ecosystem stability and prospects for its restoration as the basic unit of the biosphere during prolonged exposure to radiation and accumulation of significant doses. The goal of this research was to study the effects of high doses (60‒250 kGy) of ionizing gamma radiation on the viability of bacterial communities in frozen sedimentary rocks and modern soils, as well as to assess the aftereffect of high doses on natural samples.

The methodical exploitation of arable lands in pre-Hispanic Mesoamerica has been recognized since the 16th century, but the Spanish Conquest caused cultivated landscapes to be dramatically modified. Thus, general amazement remains great when remote sensing techniques (RS) like airborne laser scanning (LiDAR) uncover fossilized farmlands. Recent studies demonstrated that agrarian features are widespread among the remains revealed by LiDAR-derived models. Efforts are being made to map these features but few studies have focused directly on the landforms and soils which they modify. Concurrently, while paleopedology has refined the identification of anthropogenic features within soils, spatial approaches correlating soil covers and archaeological sites have received less attention as perspectives often diverge between archaeological mapping, which often focuses on intra-site elements, and soil mapping, which generally encompasses broader areas. Yet, geoscientists have used RS to predict soil parameters and demonstrated that it could increase accuracy in knowledge-based soil maps. Today, while LiDAR-derived data are facilitating archaeological mapping beyond settlement limits, high-resolution RS also offers opportunities for more accurate soil mapping and calls for harmonization of perspectives. We present a method that combines LiDAR-based RS and fieldwork in archaeology and soil science to address pre-Hispanic cultivated landscapes based on a case study in West Mexico. It focuses on the Zacapu area, where long-lasting archaeological and geoecological research offered a solid background. We used LiDAR visualizations, modeling, and satellite images to detect anthropogenic and geopedologic features. The latter was verified through field surveys and test pits. Archaeological material and soil analyses followed. All data were mapped on GIS. As a result, we were able to update and improve significantly both the archaeological and geopedologic maps. The approach further provided an unprecedented reconstruction of landscape appropriation from the 6th to the 15th century AD. It demonstrates that archaeology, geomorphology, and pedology can efficiently complete each other to address more comprehensively pre-Hispanic cultivated landscapes.

Paleoecology as originally practiced is the use of biological information found in sedimentary rocks to help determine ancient paleoenvironments. Phanerozoic sedimentary rocks are found to have in situ marine fossils that were deposited in ancient oceans. This chapter shows the distribution within environments of various different fossil groups that have a substantial fossil record. Much work on paleoecology has been spurred by the petroleum industry and the need to understand ancient environments from drill cores and cuttings as well as outcrops. In particular, one major aspect of conservation paleobiology is conservation paleoecology, which focuses on providing data from the past to manage future ecological changes. Paleoecology has deep roots that were initiated with humankind's understanding that fossils are natural objects that provide evidence on ancient ecosystems. The fossil record contains evidence for a wide variety of past environmental changes, some of which are strikingly similar to current anthropogenically created changes.

This paper explores the opportunities that arise where forest ecosystem management and cultural heritage monuments protection converge. The case study area for our analysis was the landscape surrounding the Moigrad-Porolissum Archaeological site. We emphasize that an Airborne Laser Scanning (ALS or LiDAR-Light Detection and Ranging) approach to both forest management and cultural heritage conservation is an outstanding tool, assisting policy-makers and conservationists in decision making for integrated planning and management of the environment. LiDAR-derived surface models enabled a synoptic, never-seen-before view of the ancient Roman frontiers defensive systems while also revealing the present forest road network. The thorough and accurate road inventory data are very useful for updating and modifying forest base maps and registries and also for identifying the priority sectors for archaeological discharge. The ability to identify and determine optimal routes for forest management and to locate previously unmapped ancient archaeological remains aids in reducing costs and creating operational efficiencies as well as in complying with the legislation and avoiding infringements. The potential of LiDAR to demonstrate the long-term and comprehensive human impact on wooded areas is discussed. We identified a significant historical landscape change, consisting of a deforestation period, spanning over more than 160 years, during the Roman Period in Dacia (106-271 AD). The transdisciplinary analysis of the LiDAR data provides the base for combining knowledge from archaeology, forestry and environmental history in order to achieve a thorough analysis of the landscape changes and history. In the “nature versus culture” dichotomy, the landscape, outfield areas and forests are primarily perceived as nature, while in reality they are often heavily marked by human impact. LiDAR offers an efficient method for broadening our knowledge regarding the character and extent of human interaction with landscapes - forested or otherwise.

This study describes the biodiversity of the indigenous microbial community in the sodium-chloride water brines (cryopegs) derived from ancient marine sediments and sandwiched within permafrost 100–120,000 years ago after the Arctic Ocean regression. Cryopegs remain liquid at the in situ temperature of −9 to −11 °C and make up the only habitat on the Earth that is characterized by permanently subzero temperatures, high salinity, and the absence of external influence during geological time. From these cryopegs, anaerobic and aerobic, spore-less and spore-forming, halotolerant and halophilic, psychrophilic and psychrotrophic bacteria, mycelial fungi and yeast were isolated and their activity was detected below 0 °C.

The partially correlative Alaskan dinosaur-bearing Prince Creek Formation (PCF), North Slope, lower Cantwell Formation (LCF), Denali National Park, and Chignik Formation (CF), Aniakchak National Monument, form an N–S transect that, together, provides an unparalleled opportunity to examine an ancient high-latitude terrestrial ecosystem. The PCF, 75–85° N paleolatitude, had a Mean Annual Temperature (MAT) of ~5–7 °C and a Mean Annual Precipitation (MAP) of ~1250 mm/year. The LCF, ~71° N paleolatitude, had a MAT of ~7.4 °C and MAP of ~661 mm/year. The CF, ~57° N paleolatitude, had a MAT of ~13 °C and MAP of ~1090 mm/year. The relative abundances of the large-bodied herbivorous dinosaurs, hadrosaurids and ceratopsids, vary along this transect, suggesting that these climatic differences (temperature and precipitation) played a role in the ecology of these large-bodied herbivores of the ancient north. MAP played a more direct role in their distribution than MAT, and the seasonal temperature range may have played a secondary role.

Subarctic marine ecosystems are highly sensitive to current climate and sea-ice change but long-term evidence for food web shifts is lacking. Sedimentary ancient DNA (sedaDNA) data covering the last 124,000 years combined with network analysis provides evidence for a shift from glacial (GLC) bottom-up to a deglacial-interglacial (IG) top-down food web structure. A consensus network approach, calibrated on generalized Lotka-Volterra simulations, delivers distinct modules that potentially resemble interglacial and glacial trophic structures. The glacial food web with a dominance of sea-ice adapted primary producers, densely linked with each other, supports a high module robustness and resource-driven bottom-up control. In contrast, the deglacial-interglacial food web with predominant consumers, like salmon, herring and small whales, are trophically diverse but rather fragile. Our study assumes that mobile consumers are facilitated by habitat expansion through submerged shelves and ice-free conditions during deglacial-interglacial periods altering the composition and structure of higher trophic levels. Our study implies that future warming, sea-ice decline and sea level rise may affect the structure and stability of subarctic consumer-driven, top-down food webs with adverse consequences for ecosystem services.

Human populations and their use of land have transformed most of the terrestrial biosphere into anthropogenic biomes (anthromes), causing a variety of novel ecological patterns and processes to emerge. To assess whether human populations and their use of land have directly altered the terrestrial biosphere sufficiently to indicate that the Earth system has entered a new geological epoch, spatially explicit global estimates of human populations and their use of land were analysed across the Holocene for their potential to induce irreversible novel transformation of the terrestrial biosphere. Human alteration of the terrestrial biosphere has been significant for more than 8000 years. However, only in the past century has the majority of the terrestrial biosphere been transformed into intensively used anthromes with predominantly novel anthropogenic ecological processes. At present, even were human populations to decline substantially or use of land become far more efficient, the current global extent, duration, type and intensity of human transformation of ecosystems have already irreversibly altered the terrestrial biosphere at levels sufficient to leave an unambiguous geological record differing substantially from that of the Holocene or any prior epoch. It remains to be seen whether the anthropogenic biosphere will be sustained and continue to evolve.

The first humans to reach the Americas are likely to have come via a coastal route For much of the 20th century, most archaeologists believed humans first colonized the Americas ∼13,500 years ago via an overland route that crossed Beringia and followed a long and narrow, mostly ice-free corridor to the vast plains of central North America. There, Clovis people and their descendants hunted large game and spread rapidly through the New World. Twentieth-century discoveries of distinctive Clovis artifacts throughout North America, some associated with mammoth or mastodon kill sites, supported this “Clovis-first” model. North America's coastlines and their rich marine, estuarine, riverine, and terrestrial ecosystems were peripheral to the story of how and when the Americas were first settled by humans. Recent work along the Pacific coastlines of North and South America has revealed that these environments were settled early and continuously provided a rich diversity of subsistence options and technological resources for New World hunter-gatherers.