Microbial symbionts are shared between ants and their associated beetles.

The transmission of microbial symbionts across animal species could strongly affect their biology and evolution, but our understanding of transmission patterns and dynamics is limited. Army ants (Formicidae: Dorylinae) and their hundreds of closely associated insect guest species (myrmecophiles) can provide unique insights into interspecific microbial symbiont sharing. Here, we compared the microbiota of workers and larvae of the army ant Eciton burchellii with those of 13 myrmecophile beetle species using 16S rRNA amplicon sequencing. We found that the previously characterized specialized bacterial symbionts of army ant workers were largely absent from ant larvae and myrmecophiles, whose microbial communities were usually dominated by Rickettsia, Wolbachia, Rickettsiella and/or Weissella. Strikingly, different species of myrmecophiles and ant larvae often shared identical 16S rRNA genotypes of these common bacteria. Protein-coding gene sequences confirmed the close relationship of Weissella strains colonizing army ant larvae, some workers and several myrmecophile species. Unexpectedly, these strains were also similar to strains infecting dissimilar animals inhabiting very different habitats: trout and whales. Together, our data show that closely interacting species can share much of their microbiota, and some versatile microbial species can inhabit and possibly transmit across a diverse range of hosts and environments.

Historical evaluation of the in vivo adventitious virus test and its potential for replacement with next generation sequencing (NGS).

The Consortium on Adventitious Agent Contamination in Biomanufacturing (CAACB) collected historical data from 20 biopharmaceutical industry members on their experience with the in vivo adventitious virus test, the in vitro virus test, and the use of next generation sequencing (NGS) for viral safety. Over the past 20 years, only three positive in vivo adventitious virus test results were reported, and all were also detected in another concurrent assay. In more than three cases, data collected as a part of this study also found that the in vivo adventitious virus test had given a negative result for a sample that was later found to contain virus. Additionally, the in vivo adventitious virus test had experienced at least 21 false positives and had to be repeated an additional 21 times all while using more than 84,000 animals. These data support the consideration and need for alternative broad spectrum viral detection tests that are faster, more sensitive, more accurate, more specific, and more humane. NGS is one technology that may meet this need. Eighty one percent of survey respondents are either already actively using or exploring the use of NGS for viral safety. The risks and challenges of replacing in vivo adventitious virus testing with NGS are discussed. It is proposed to update the overall virus safety program for new biopharmaceutical products by replacing in vivo adventitious virus testing approaches with modern methodologies, such as NGS, that maintain or even improve the final safety of the product.

Neuroanatomical differentiation associated with alternative reproductive tactics in male arid land bees, Centris pallida and Amegilla dawsoni.

Alternative reproductive tactics (ARTs) occur when there is categorical variation in the reproductive strategies of a sex within a population. These different behavioral phenotypes can expose animals to distinct cognitive challenges, which may be addressed through neuroanatomical differentiation. The dramatic phenotypic plasticity underlying ARTs provides a powerful opportunity to study how intraspecific nervous system variation can support distinct cognitive abilities. We hypothesized that conspecific animals pursuing ARTs would exhibit dissimilar brain architecture. Dimorphic males of the bee species Centris pallida and Amegilla dawsoni use alternative mate location strategies that rely primarily on either olfaction (large-morph) or vision (small-morph) to find females. This variation in behavior led us to predict increased volumes of the brain regions supporting their primarily chemosensory or visual mate location strategies. Large-morph males relying mainly on olfaction had relatively larger antennal lobes and relatively smaller optic lobes than small-morph males relying primarily on visual cues. In both species, as relative volumes of the optic lobe increased, the relative volume of the antennal lobe decreased. In addition, A. dawsoni large males had relatively larger mushroom body lips, which process olfactory inputs. Our results suggest that the divergent behavioral strategies in ART systems can be associated with neuroanatomical differentiation.

Experience-expectant brain plasticity corresponds to caste-specific abiotic challenges in dampwood termites (Zootermopsis angusticollis and Z. nevadensis).

Hypotheses for adaptive brain investment predict associations between the relative sizes of functionally distinct brain regions and the sensory/cognitive demands animals confront. We measured developmental differences in the relative sizes of visual processing brain regions (optic lobes) among dampwood termite castes to test whether optic lobe investment matches caste differences in exposure to visually complex environments. The winged primary reproductives (Kings/Queens) on mating flights are the only caste to leave the dark nest cavities and as predicted, Kings/Queens showed greater relative investment in optic lobe tissue than nestbound (neotenic) reproductives and soldiers in two dampwood termite species (Zootermopsis angusticollis and Z. nevadensis). Relative optic lobe size spanned more than an order of magnitude among the castes we studied, suggesting the growth of the optic lobes incurs substantial tissue costs. Optic lobe growth was experience-expectant: the optic lobes of Z. angusticollis brachypterous nymphs, which typically develop into Kings/Queens, were relatively larger than the optic lobes of apterous nymphs, which precede neotenics and soldiers, and relative optic lobe size of nestbound brachypterous nymphs was statistically similar to that of Kings/Queens. Experience-expectant brain tissue growth is rarely documented in insects, likely because it entails high potential costs of tissue production and maintenance and relatively low immediate sensory/cognitive benefits. We develop hypotheses for the conditions under which experience-expectant growth in brain regions could be favored by natural selection.

Changes in mortality patterns and place of death during the COVID-19 pandemic: A descriptive analysis of mortality data across four nations.

BACKGROUND: Understanding patterns of mortality and place of death during the COVID-19 pandemic is important to help provide appropriate services and resources. AIMS: To analyse patterns of mortality including place of death in the United Kingdom (UK) (England, Wales, Scotland and Northern Ireland) during the COVID-19 pandemic to date. DESIGN: Descriptive analysis of UK mortality data between March 2020 and March 2021. Weekly number of deaths was described by place of death, using the following definitions: (1) expected deaths: average expected deaths estimated using historical data (2015-19); (2) COVID-19 deaths: where COVID-19 is mentioned on the death certificate; (3) additional non-COVID-19 deaths: above expected but not attributed to COVID-19; (4) baseline deaths: up to and including expected deaths but excluding COVID-19 deaths. RESULTS: During the analysis period, 798,643 deaths were registered in the UK, of which 147,282 were COVID-19 deaths and 17,672 were additional non-COVID-19 deaths. While numbers of people who died in care homes and hospitals increased above expected only during the pandemic waves, the numbers of people who died at home remained above expected both during and between the pandemic waves, with an overall increase of 41%. CONCLUSIONS: Where people died changed during the COVID-19 pandemic, with an increase in deaths at home during and between pandemic waves. This has implications for planning and organisation of palliative care and community services. The extent to which these changes will persist longer term remains unclear. Further research could investigate whether this is reflected in other countries with high COVID-19 mortality.

Duodenal Obstruction after Endovascular Repair of a Ruptured Abdominal Aorta Aneurysm.

Endovascular repair has become the most frequent approach in the management of the ruptured infra-renal abdominal aorta aneurysm. When managing the ruptured patient with a significant retroperitoneal hematoma, abdominal compartment syndrome is often a consideration. Duodenal obstruction from the hematoma is rare and not typically a consideration. In the case of our patient, the intra-abdominal pressures were successfully managed conservatively. The large retroperitoneal hematoma, however, encased and obstructed the duodenum ultimately requiring a gastrojejunostomy. Similar rare cases of duodenal obstruction have been reported after open aortic repairs. We have not identified other cases in the literature of duodenal obstruction after endovascular management of a ruptured abdominal aorta aneurysm. We want to raise awareness to the possibility. In our opinion, conservative management would still be the preferred course of action, even if surgical management was ultimately required for the duodenal obstruction, as it reduces the initial insult in the patient with the aneurysmal rupture.

Brain structure differences between solitary and social wasp species are independent of body size allometry.

Evolutionary transitions in social behavior are often associated with changes in species' brain architecture. A recent comparative analysis showed that the structure of brains of wasps in the family Vespidae differed between solitary and social species: the mushroom bodies, a major integrative brain region, were larger relative to brain size in the solitary species. However, the earlier study did not account for body size effects, and species' relative mushroom body size increases with body size in social Vespidae. Here we extend the previous analysis by measuring the effects of body size variation on brain structure differences between social and solitary vespid wasps. We asked whether total brain volume was greater relative to body size in the solitary species, and whether relative mushroom body size was greater in solitary species, after accounting for body size effects. Both total brain volume and relative mushroom body volume were significantly greater in the solitary species after accounting for body size differences. Therefore, body size allometry did not explain the solitary versus social species differences in brain structure. The evolutionary transition from solitary to social behavior in Vespidae was accompanied by decreases in total brain size and in relative mushroom body size.

New insights into the performance characteristics of the Planova-series hollow-fiber parvovirus filters using confocal and electron microscopy.

Virus filtration remains a critical step in the downstream process for the production of monoclonal antibodies and other mammalian cell-derived biotherapeutics. Recent studies have shown large differences in virus capture behavior of different virus filters, although the origin of these differences is still unclear. The objective of this study was to use confocal and scanning electron microscopy to directly evaluate the capture of virus-size nanoparticles in Planova 20N and BioEX hollow-fiber virus filters. Confocal images of fluorescent nanoparticles were quantified using ImageJ image processing software based on the measured fluorescence intensity of the labeled nanoparticles. Nanoparticle capture by the Planova BioEX was independent of transmembrane pressure from 10 to 45 psi. In contrast, the Planova 20N showed significant differences in nanoparticle capture profile at low pressure, consistent with literature data showing virus breakthrough under these conditions. Images obtained after a process interruption show significant migration of previously captured nanoparticles in the Planova 20N filters but not in the BioEX. These results provide important insights into the nature of virus capture in different virus filters and its dependence on the underlying structure of the virus filtration membranes.

Extreme Insolation: Climatic Variation Shapes the Evolution of Thermal Tolerance at Multiple Scales.

The climatic variability hypothesis (CVH) is a cornerstone of thermal ecology, predicting the evolution of wider organismal thermal tolerance ranges in more thermally variable environments. Thermal tolerance ranges depend on both upper and lower tolerance limits (critical thermal maxima [[Formula: see text]] and critical thermal minima [[Formula: see text]]), which may show different responses to environmental gradients. To delineate the relative effects of mean and extreme temperatures on thermal tolerances, we conducted a within-latitude comparative test of CVH predictions for army ants (Dorylinae) at multiple scales: across elevations, in seasonal versus aseasonal forests, and in subterranean versus surface microhabitats. Consistent with the CVH, thermally buffered subterranean species had narrower thermal tolerance ranges. Both [Formula: see text] and [Formula: see text] decreased with elevation for subterranean species. In contrast, aboveground species (those exposed to insolation) showed a decrease in [Formula: see text] but no change in [Formula: see text] across elevations. Furthermore, greater seasonal temperature variation in dry forests correlated with increased [Formula: see text] but not [Formula: see text]. These patterns suggest that [Formula: see text] and [Formula: see text] respond to different abiotic selective forces: habitat-specific exposure to extreme insolation corresponds to [Formula: see text] differences but not to [Formula: see text] variation. We predict that increasingly frequent heat spikes associated with climate change will have habitat-specific physiological consequences for ectothermic animals. Models predicting climate change impacts should account for species microhabitat uses and within-latitude differences in temperature seasonality.

Implications of iterative communication for biological system performance.

The performance of integrated biological systems can often be described by the behavior of component subunits: the proportion of subunits performing an activity, and the rate of recruitment to the activity, can be relevant to system performance. We develop a model for activation of subunits (receivers) to a task when activation requires repeated signals (iterative communication). The model predicts how system performance will be affected by the parameters of iterative communication. Receiver activation is influenced by the frequency of stimulation, by forgetting about past interactions, and by the number of stimuli needed to activate the receivers. These parameters, along with the probability of activated receivers returning to a de-activated state, modulate the system-wide time course of activation and the steady-state proportion of activated receivers. Parameters can interact to affect system-wide activation, and multiple parameter combinations can yield similar patterns of activation. Group performance is less variable at higher stimulation frequencies and in systems with greater numbers of receivers. Biological constraints on iterative communication, such as time and energy costs, may limit the parameter values that are feasible for a given system. Iterative communication parameters may be subject to natural selection at the system (group) level because they affect system performance.

The neurobiology of climate change.

Directional climate change (global warming) is causing rapid alterations in animals' environments. Because the nervous system is at the forefront of animals' interactions with the environment, the neurobiological implications of climate change are central to understanding how individuals, and ultimately populations, will respond to global warming. Evidence is accumulating for individual level, mechanistic effects of climate change on nervous system development and performance. Climate change can also alter sensory stimuli, changing the effectiveness of sensory and cognitive systems for achieving biological fitness. At the population level, natural selection forces stemming from directional climate change may drive rapid evolutionary change in nervous system structure and function.

Complex body size differences in thermal tolerance among army ant workers (Eciton burchellii parvispinum).

In social insects, group members can differ in thermal physiology, and these differences may affect colony function. Upper thermal tolerance limits (CTmax) generally increase with body size among and within ant species, but size effects on lower thermal tolerances (CTmin) are poorly known. To test whether CTmin co-variation with body size matched patterns for CTmax, we measured CTmax and CTmin in workers of four size-based worker subcastes in the army ant Eciton burchellii parvispinum. CTmax increased with worker body size as expected. CTmin showed a more complex relationship with size: the two intermediate-size subcastes (media and porters) tolerated lower temperatures than the smallest (minims) and the largest (soldiers) worker subcastes. Body-size effects on CTmax were not predictive of body-size effects on CTmin. These patterns held for colonies collected across elevations that spanned approximately 8 °C in mean annual temperature, even though high-elevation colonies had significantly lower CTmin overall. We predict Eciton army ant subcastes will be differentially affected by directional changes in high and low temperature extremes. Worker subcastes perform distinct but complementary roles in colony function, and differential temperature effects among subcastes could impair colony performance and negatively impact colony fitness.

The structured diversity of specialized gut symbionts of the New World army ants.

Symbiotic bacteria play important roles in the biology of their arthropod hosts. Yet the microbiota of many diverse and influential groups remain understudied, resulting in a paucity of information on the fidelities and histories of these associations. Motivated by prior findings from a smaller scale, 16S rRNA-based study, we conducted a broad phylogenetic and geographic survey of microbial communities in the ecologically dominant New World army ants (Formicidae: Dorylinae). Amplicon sequencing of the 16S rRNA gene across 28 species spanning the five New World genera showed that the microbial communities of army ants consist of very few common and abundant bacterial species. The two most abundant microbes, referred to as Unclassified Firmicutes and Unclassified Entomoplasmatales, appear to be specialized army ant associates that dominate microbial communities in the gut lumen of three host genera, Eciton, Labidus and Nomamyrmex. Both are present in other army ant genera, including those from the Old World, suggesting that army ant symbioses date back to the Cretaceous. Extensive sequencing of bacterial protein-coding genes revealed multiple strains of these symbionts coexisting within colonies, but seldom within the same individual ant. Bacterial strains formed multiple host species-specific lineages on phylogenies, which often grouped strains from distant geographic locations. These patterns deviate from those seen in other social insects and raise intriguing questions about the influence of army ant colony swarm-founding and within-colony genetic diversity on strain coexistence, and the effects of hosting a diverse suite of symbiont strains on colony ecology.

Non-Nutritive Polyol Sweeteners Differ in Insecticidal Activity When Ingested by Adult Drosophila melanogaster (Diptera: Drosophilidae).

Previous work showed the non-nutritive polyol sweetener Erythritol was toxic when ingested by Drosophila melanogaster (Meigen, 1930). This study assessed whether insect toxicity is a general property of polyols. Among tested compounds, toxicity was highest for erythritol. Adult fruit flies (D. melanogaster) fed erythritol had reduced longevity relative to controls. Other polyols did not reduce longevity; the only exception was a weaker but significant reduction of female (but not male) longevity when flies were fed D-mannitol. We conclude at least some non-nutritive polyols are not toxic to adult D. melanogaster when ingested for 17 days. The longer time course (relative to erythritol) and female specificity of D-mannitol mortality suggests different mechanisms for D-mannitol and erythritol toxicity to D. melanogaster.

Distributed cognition and social brains: reductions in mushroom body investment accompanied the origins of sociality in wasps (Hymenoptera: Vespidae).

The social brain hypothesis assumes the evolution of social behaviour changes animals' ecological environments, and predicts evolutionary shifts in social structure will be associated with changes in brain investment. Most social brain models to date assume social behaviour imposes additional cognitive challenges to animals, favouring the evolution of increased brain investment. Here, we present a modification of social brain models, which we term the distributed cognition hypothesis. Distributed cognition models assume group members can rely on social communication instead of individual cognition; these models predict reduced brain investment in social species. To test this hypothesis, we compared brain investment among 29 species of wasps (Vespidae family), including solitary species and social species with a wide range of social attributes (i.e. differences in colony size, mode of colony founding and degree of queen/worker caste differentiation). We compared species means of relative size of mushroom body (MB) calyces and the antennal to optic lobe ratio, as measures of brain investment in central processing and peripheral sensory processing, respectively. In support of distributed cognition predictions, and in contrast to patterns seen among vertebrates, MB investment decreased from solitary to social species. Among social species, differences in colony founding, colony size and caste differentiation were not associated with brain investment differences. Peripheral lobe investment did not covary with social structure. These patterns suggest the strongest changes in brain investment--a reduction in central processing brain regions--accompanied the evolutionary origins of eusociality in Vespidae.

Microhabitat and body size effects on heat tolerance: implications for responses to climate change (army ants: Formicidae, Ecitoninae).

1. Models that predict organismal and population responses to climate change may be improved by considering ecological factors that affect species thermal tolerance. Species differences in microhabitat use can expose animals to diverse thermal selective environments at a given site and may cause sympatric species to evolve different thermal tolerances. 2. We tested the hypothesis that species differences in body size and microhabitat use (above- vs. below-ground activity) would correspond to differences in thermal tolerance (maximum critical temperatures: CTmax ). Thermal buffering effects of soil can reduce exposure to extreme high temperatures for below-ground active species. We predicted larger-bodied individuals and species would have higher CTmax and that species mean CTmax would covary positively with degree of above-ground activity. We used Neotropical army ants (Formicidae: Ecitoninae) as models. Army ants vary in microhabitat use from largely subterranean to largely above-ground active species and are highly size polymorphic. 3. We collected data on above- and below-ground temperatures in habitats used by army ants to test for microhabitat temperature differences, and we conducted CTmax assays for army ant species with varying degrees of surface activity and with different body sizes within and between species. We then tested whether microhabitat use was associated with species differences in CTmax and whether microhabitat was a better predictor of CTmax than body size for species that overlapped in size. 4. Microhabitat use was a highly significant predictor of species' upper thermal tolerance limits, both for raw data and after accounting for the effects of phylogeny. Below-ground species were more thermally sensitive, with lower maximum critical temperatures (CTmax ). The smallest workers within each species were the least heat tolerant, but the magnitude of CTmax change with body size was greater in below-ground species. Species-typical microhabitat was a stronger predictor of CTmax than body size for species that overlapped in size. Compared to the soil surface, 10-cm subsoil was a significantly moderated thermal environment for below-ground army ants, while maximum surface raid temperatures sometimes exceeded CTmax for the most thermally sensitive army ant castes. 5. We conclude sympatric species differences in thermal physiology correspond to microhabitat use. These patterns should be accounted for in models of species and community responses to thermal variation and climate change.

Cumulative Effects of Foraging Behavior and Social Dominance on Brain Development in a Facultatively Social Bee (Ceratina australensis).

In social insects, both task performance (foraging) and dominance are associated with increased brain investment, particularly in the mushroom bodies. Whether and how these factors interact is unknown. Here we present data on a system where task performance and social behavior can be analyzed simultaneously: the small carpenter bee Ceratina australensis. We show that foraging and dominance have separate and combined cumulative effects on mushroom body calyx investment. Female C. australensis nest solitarily and socially in the same populations at the same time. Social colonies comprise two sisters: the social primary, which monopolizes foraging and reproduction, and the social secondary, which is neither a forager nor reproductive but rather remains at the nest as a guard. We compare the brains of solitary females that forage and reproduce but do not engage in social interactions with those of social individuals while controlling for age, reproductive status, and foraging experience. Mushroom body calyx volume was positively correlated with wing wear, a proxy for foraging experience. We also found that, although total brain volume did not vary among reproductive strategies (solitary vs. social nesters), socially dominant primaries had larger mushroom body calyx volumes (corrected for both brain and body size variation) than solitary females; socially subordinate secondaries (that are neither dominant nor foragers) had the least-developed mushroom body calyces. These data demonstrate that sociality itself does not explain mushroom body volume; however, achieving and maintaining dominance status in a group was associated with mushroom body calyx enlargement. Dominance and foraging effects were cumulative; dominant social primary foragers had larger mushroom body volumes than solitary foragers, and solitary foragers had larger mushroom body volumes than nonforaging social secondary guards. This is the first evidence for cumulative effects on brain development by dominance and task performance.

A 5'-terminal phosphate is required for stable ternary complex formation and translation of leaderless mRNA in Escherichia coli.

The bacteriophage λ's cI mRNA was utilized to examine the importance of the 5'-terminal phosphate on expression of leadered and leaderless mRNA in Escherichia coli. A hammerhead ribozyme was used to produce leadered and leaderless mRNAs, in vivo and in vitro, that contain a 5'-hydroxyl. Although these mRNAs may not occur naturally in the bacterial cell, they allow for the study of the importance of the 5'-phosphorylation state in ribosome binding and translation of leadered and leaderless mRNAs. Analyses with mRNAs containing either a 5'-phosphate or a 5'-hydroxyl indicate that leaderless cI mRNA requires a 5'-phosphate for stable ribosome binding in vitro as well as expression in vivo. Ribosome-binding assays show that 30S subunits and 70S ribosomes do not bind as strongly to 5'-hydroxyl as they do to 5'-phosphate containing leaderless mRNA and the tRNA-dependent ternary complex is less stable. Additionally, filter-binding assays revealed that the 70S ternary complex formed with a leaderless mRNA containing a 5'-hydroxyl has a dissociation rate (k(off)) that is 4.5-fold higher compared with the complex formed with a 5'-phosphate leaderless mRNA. Fusion to a lacZ reporter gene revealed that leaderless cI mRNA expression with a 5'-hydroxyl was >100-fold lower than the equivalent mRNA with a 5'-phosphate. These data indicate that a 5'-phosphate is an important feature of leaderless mRNA for stable ribosome binding and expression.

Genetic evidence for landscape effects on dispersal in the army ant Eciton burchellii.

Inhibited dispersal, leading to reduced gene flow, threatens populations with inbreeding depression and local extinction. Fragmentation may be especially detrimental to social insects because inhibited gene flow has important consequences for cooperation and competition within and among colonies. Army ants have winged males and permanently wingless queens; these traits imply male-biased dispersal. However, army ant colonies are obligately nomadic and have the potential to traverse landscapes. Eciton burchellii, the most regularly nomadic army ant, is a forest interior species: colony raiding activities are limited in the absence of forest cover. To examine whether nomadism and landscape (forest clearing and elevation) affect population genetic structure in a montane E. burchellii population, we reconstructed queen and male genotypes from 25 colonies at seven polymorphic microsatellite loci. Pairwise genetic distances among individuals were compared to pairwise geographical and resistance distances using regressions with permutations, partial Mantel tests and random forests analyses. Although there was no significant spatial genetic structure in queens or males in montane forest, dispersal may be male-biased. We found significant isolation by landscape resistance for queens based on land cover (forest clearing), but not on elevation. Summed colony emigrations over the lifetime of the queen may contribute to gene flow in this species and forest clearing impedes these movements and subsequent gene dispersal. Further forest cover removal may increasingly inhibit Eciton burchellii colony dispersal. We recommend maintaining habitat connectivity in tropical forests to promote population persistence for this keystone species.

Comparative analysis of constraints and caste differences in brain investment among social paper wasps.

We compared species mean data on the size of functionally distinct brain regions to test the relative rates at which investment in higher-order cognitive processing (mushroom body calyces) versus peripheral sensory processing (optic and antennal lobes) increased with increasing brain size. Subjects were eusocial paper wasps from queen and worker castes of 10 species from different genera. Relative investment in central processing tissue increased with brain size at a higher rate than peripheral structure investment, demonstrating that tissue devoted to higher-order cognitive processing is more constrained by brain size. This pattern held for raw data and for phylogenetically independent contrasts. These findings suggest that there is a minimum necessary investment in peripheral sensory processing brain tissue, with little to gain from additional investment. In contrast, increased brain size provides opportunities to invest in additional higher-order cognitive processing tissue. Reproductive castes differed within species in brain tissue investment, with higher central-to-peripheral brain tissue ratios in queens than in workers. Coupled with previous findings that paper wasp queen, but not worker, brain architecture corresponds to ecological and social variation, queen brain evolution appears to be most strongly shaped by cognitive demands, such as social interactions. These evolutionary patterns of neural investment echo findings in other animal lineages and have important implications, given that a greater investment in higher-order processing has been shown to increase the prevalence of complex and flexible behaviors across the animal kingdom.