Natural History Museum of Los Angeles County

To holistically understand the biology of animals, we must unravel the complexities and specificities of host-microbe interactions across animal taxa. Birds represent enigmatic and scientifically compelling hosts in which to understand these interactions. Here, we present a brief summary of a series of conversations among avian microbiome researchers regarding methodological challenges facing the avian microbiome field, where most research to date has focused on bacterial communities of the gut. Collectively, we acknowledged a commonly shared but underreported issue facing the avian microbiome field: that of difficulty in obtaining high-quality and high-yield microbial DNA from avian fecal samples. We discuss some of the potential reasons underlying low DNA yields, such as inhibitory compounds and rapid DNA degradation, and provide recommendations for how researchers in the avian microbiome field might cope with these methodological challenges. Collective and dedicated efforts to address these challenges will be required for a robust understanding of host-microbe interactions in avian systems.

The magnitude of the problem of sickle cell disease (SCD) in India is very large and diverse. For people living with SCD there are several unmet health care needs making it pertinent to focus on recognizing the important public health burden of SCD in the country. In a bid to achieve this goal, the Indian College of Hematology (ICH) of the Indian Society of Hematology and Blood Transfusion (ISHBT) in collaboration with Indian Council of Medical Research (ICMR) has formulated a Guideline on Management and Control of Sickle Cell Disease in India. This was achieved by a national taskforce comprising top experts from the field who held multiple sessions to deliberate on different aspects and form consensus on preparing a comprehensive document on SCD care in India. The taskforce has presented its recommendations on various aspects of SCD in India, all of which have been evaluated based on the best evidence. Where the evidence was weak, the recommendations have been based on consensus among the experts. This review which is adapted from the comprehensive guideline document gives a concise treatise on various aspects of sickle cell disease in India along with specific recommendations. The section on screening and diagnosis provides an evidence-based background to scientifically select the most appropriate and feasible test option(s) in various Indian practice settings. The other aspects covered in this review are management of SCD in stable condition, iron overload and chelation therapy, vaso-occlusive crisis, management of other complications of SCD, blood transfusion in SCD, haematopoietic stem cell transplant and gene therapy in SCD, immunization and antibiotic prophylaxis in SCD and monitoring of patients with SCD. It also gives guidance on special circumstances such as pregnancy and surgery in SCD. It concludes with a note on prevention and control of SCD in India with an outline of a defined roadmap to make this possible.

Consciousness is often treated as an evolutionary anomaly, a costly capacity with unclear adaptive origins. Here, cognition and consciousness are distinguished as separate evolutionary lineages, with consciousness arising when an organism must coordinate otherwise distinct regulatory processes to resolve competing demands affecting its own viability. Its functional precursors predate nervous systems, emerging first in boundary-preserving chemical and metabolic regulation. An evolutionary ladder is developed in which proto-control preserves boundaries by selectively permitting, inhibiting, and localizing destruction; meta-control arbitrates among competing local controllers; and settlement control resolves conflict by making competing regulatory demands comparable and jointly binding for policy selection. It follows that artificial consciousness will not emerge from greater cognitive sophistication alone; it will require self-maintaining systems that settle competing demands under real constraint. The framework yields six falsifiable predictions spanning comparative biology, neuroscience, and artificial intelligence. On this view, consciousness is not evolution’s anomaly but its solution: self-anchored, cross-domain settlement under constraint.

ABSTRACT Aim In west‐central California, the landscapes west of the San Andreas fault include the arc plutons of the Salinian block which form the geologic backbone of several South Coast mountain ranges. In the early Miocene Salinia was adjacent to the southern Sierra Nevada, but was subsequently captured by the Pacific Plate, with right‐lateral slip migration displacing terranes northwestwards since the formation of the San Andreas fault. We hypothesise that a migrating Salinia has played an important role in the biogeographic history of dispersal‐limited Megahexura mygalomorph spiders. Location Central and southern California Floristic Province, including Salinia (Santa Lucia, Sierra de Salinas, Gabilan, and Santa Cruz mountains), southern Sierra Nevada, and Transverse Ranges. Taxon Megahexura , Family Megahexuridae, Infraorder Mygalomorphae, Order Araneae. Methods Analyses of ultraconserved element (UCE) nuclear loci and single nucleotide polymorphism (SNP) data are used to estimate ingroup relationships and genetic population structuring, root placement and divergence timing, and a Bayesian‐estimated biogeographic history of Megahexura . Results Phylogenomics strongly supports three primary phylogenetic lineages in Megahexura , with a common ancestor that diverged in the early to mid‐Miocene, depending upon calibration parameters. The southern Sierra Nevada is reconstructed as the centre of origin for Megahexura , and one Megahexura lineage now resides mostly on ranges that include Salinian basement rocks. In the Santa Lucia Range, phylogenetic directionality is structured from north to south. The southern Sierra Nevada is also a more recent ancestral area for Megahexura populations currently occupying the western and southern Transverse Ranges, some of which have expanded northwestwards to secondarily contact Salinian populations. Main Conclusions We uncover a unique biogeographic history where instead of animal populations dispersing recently over an old landscape, phylogenomic patterns are best explained by the landscape itself moving, carrying animal populations. Our results are consistent with a compelling Salinian biogeography and represent a possible case of Neogene divergence driven principally by plate tectonics.

Abstract Tropical rivers in Australia and New Guinea (Sahul) provide a rare natural experiment in vertebrate evolution: unlike other continental systems, their freshwater ichthyofaunas are composed almost entirely of marine-derived lineages rather than primary freshwater fishes. This unique biogeographic setting enables replicated tests of why some marine-to-freshwater transitions give rise to extensive adaptive radiations whereas others remain species-poor, and whether these outcomes reflect ecological opportunity or temporally structured paleoenvironmental constraints. Using a densely sampled, time-calibrated phylogenomic framework spanning 2,303 teleost species, we identified a likely range of 27–34 marine-to-freshwater transitions during the Cenozoic, including a pronounced Middle Miocene peak (16–11 Ma). Although ecological opportunity in Sahul rivers enabled repeated colonization in the absence of dominant primary freshwater incumbents, younger freshwater lineages nevertheless diversify faster than older ones, contradicting the expectation that early arrivers should undergo elevated diversification when accessing vacant niche space. Although some colonizations coincide with bursts of speciation consistent with adaptive radiation, many yielded few species despite long residence times. Functional trait analyses likewise revealed no consistent relationship between colonization timing, ecological breadth, or diversification rate, although expanded functional space characterizes previously proposed Sahul adaptive radiations. Comparisons with paleoenvironmental curves indicate that colonization success correlates with sea-level minima and low-oxygen conditions, suggesting that Earth history dynamics modulated when ecological opportunity was accessible. Our results show that although ecological opportunity enabled repeated freshwater invasions into the Sahul region, diversification outcomes are governed by the interaction of paleoenvironmental dynamics and possibly lineage-specific traits, generating stark asymmetries in freshwater radiations. Significance statement Tropical rivers in Australia and New Guinea host one of the most unusual continental freshwater fish assemblages on Earth, composed almost entirely of marine-derived lineages. This system allows asking why some colonizing lineages diversify dramatically while others remain species-poor on a continental scale. Using large-scale phylogenomic and functional trait data, we show that early arrival alone does not predict diversification success. Instead, the lineages that radiate most successfully are those whose arrival coincides with windows of paleoenvironmental opportunity created by sea-level and oxygen fluctuations. These results reveal that the fates of colonizing lineages are shaped not only by ecological opportunity, but also by Earth-history dynamics that govern when, where, and how species can invade and diversify.