Biological Reviews最新文献

Troodontidae is a clade of small-to medium-sized maniraptoran theropods that mainly lived in Laurasia (modern Asia, North America and Europe) during the Jurassic and Cretaceous periods and are believed to have had a variety of diets. The uniqueness of troodontid teeth suggests that they diverged from the typical flesh-based diet of non-avian theropods. Some Asian troodontids even lack tooth serrations completely, which has been linked to herbivory or omnivory. However, troodontids still possessed multiple traits suited for predation. These include a large curved second pedal digit; laterally compressed, curved, and serrated teeth; and ‘puncture-and-pull’ microwear on their teeth. Extrinsic evidence, such as stomach contents and gastric pellets, supports a diverse dietary intake among troodontids with evidence that they ingested both plant and animal material. Environmental, morphological, and biogeochemical analyses suggest that the iconic North American troodontid, Troodon, was likely to have been omnivorous, potentially preying on both plants and small animals, such as mammals and baby dinosaurs (hatched or unhatched). Our understanding of different diets among troodontids remains limited due to the sparsity of both relevant fossil material and palaeodiet research. Nevertheless, what information we have on troodontid diet informs ancestral deinonychosaurian and paravian diets, which we suggest were omnivorous. We encourage research into troodontids outside the Late Cretaceous of North America and further study of troodontid biogeochemistry and postcranial anatomy to improve our understanding of troodontid diet and the larger story of theropod ecological diversity.

Empathy is the glue that holds societies together and yet several fundamental questions about empathy persist. What is empathy (the definitional question)? Is it uniquely human and, if not, which nonhuman animals possess empathy (the distribution question)? Which type or quality of empathy is realized in different species (the quality question)? To tackle these three questions, we developed a species-sensitive, multidimensional profile account of empathy. The main function of this account is to enable cross-species comparisons and to capture the rich variety of typical empathetic phenomena. Therefore, we aim to characterize behaviour-based cognitive profiles of empathy which are built on multifactorial characterizations of the dimensions of empathy and of the features realizing these dimensions. The distribution question can be answered by assessing family resemblances of profiles of empathy to paradigmatic cases of empathy. Answers to the quality question can be provided with reference to the relevant empathy profile, which allows us to describe and predict associated behaviours. To gain an initial understanding of the feasibility of this framework for interspecies comparisons, we applied it to four groups of animals: rodents, apes, canids and corvids. Comparing these groups, we demonstrate that each species has a specific empathy profile which has a predictive power: in complex situations requiring empathy, distinct profiles will result in more distinct behavioural responses whereas similar profiles will result in more similar responses, even among phylogenetically distinct groups. This new multidimensional profile account enables fine-grained comparisons within and between species instead of the prevailing all or nothing perspectives of empathy. Furthermore, it offers the integration of phylogenetic and ontogenetic perspectives thereby providing a crucial tool to explicate the notion of empathy to humans and other animals in a species-sensitive way. We demonstrate this framework by applying it specifically to empathy, and the framework's advantages invite it to be generalized to all rich and flexible cognitive abilities in nonhuman animals.

Tumour cell dormancy is a reversible, non-proliferative state in which cancer cells arrest in the G0 phase of the cell cycle. Increasingly recognized as a critical survival strategy, dormancy enables cancer cells to withstand therapeutic insult, escape immune surveillance, and endure hostile microenvironments. Clinically, dormant cells underlie extended asymptomatic intervals following primary treatment and are notably implicated in estrogen receptor-positive (ER⁺) breast cancer, prostate cancer, and clear cell renal cell carcinoma. In this review, we synthesize recent insights into hypoxia-mediated dormancy and, using breast cancer bone metastasis as an archetypal model, delineate how spatiotemporally heterogeneous hypoxia shapes the metastatic cascade. Specifically, we show that graded hypoxia in the primary tumour initiates dormancy traits, while persistent hypoxia within metastatic niches - such as the bone marrow - reinforces and deepens quiescence. These transitions are orchestrated by stage-specific activation of hypoxia-inducible factor 1α (HIF-1α) and its dynamic transcriptional outputs. We further argue that a mechanistic understanding of dormancy requires integrative frameworks that bridge single-cell level regulatory programs - including cell-cycle arrest, translational inhibition, and metabolic reprogramming - with systems-level networks capturing the dynamic, multistage nature of metastasis. Such integration may uncover actionable vulnerabilities within dormant cell populations and guide the development of precision therapies targeting minimal residual disease.

Following the discovery of identity discrimination, particularly self and kin discrimination amongst plant competitors, research on interplant interactions has advanced significantly within plant physiology and evolutionary ecology. This review synthesizes current knowledge on how both self and kin discrimination influence plant growth, resource allocation, defence, and reproduction. I highlight their ecological and evolutionary consequences for population dynamics, community structure, and multi-trophic interactions. A key insight is that, under some circumstances, identity discrimination may shape the maintenance or erosion of genetic diversity by modulating competitive interactions and spatial genetic structure within populations. Finally, I present several open questions, such as how identity discrimination operates across gradients of plant competition and trophic levels, and propose a few testable hypotheses and experimental approaches regarding the role of competitive identity discrimination under natural settings.

Fire regimes are changing worldwide, with increases in the frequency, extent, and severity of fires posing growing risks to biodiversity. Fire severity - the degree of habitat alteration following fire - strongly influences both immediate survival and long-term recovery of fauna. Yet species' responses to severe fire are highly variable, shaped by traits, time since fire, and ecosystem context. We conducted a global systematic review of studies quantifying terrestrial vertebrate responses across fire-severity gradients. Using ordinal logistic regression, we assessed the predictive value of functional traits, time since fire, taxonomy, and ecosystem type for species' abundance and occurrence after fire. Across all severity comparisons, most species showed neutral responses; however, high severity fires elicited both more negative and more positive responses than low severity fires. Species with weak shelter, canopy-foraging habits, and preferences for closed canopies were more likely to decline after high severity fire. Negative responses diminished with increasing time since fire, highlighting opportunities for population recovery. Our findings identify functional traits that confer vulnerability to severe fire and provide a basis for predicting species' responses in unstudied taxa or regions. Targeted management, particularly within the first few years post-fire, will be critical to safeguard susceptible species as high severity fires become more frequent.

Numerous studies have revealed the importance of research on the communities capable of colonizing animal surfaces (epibionts) and the animals on which they live (basibionts). Very few studies have considered epizoic diatoms, and there are gaps and biases in our knowledge, including the choice of basibionts, the methods used, and the habitats in which they live. This literature review aims to (i) identify the main basibionts that host diatom communities and the diatom taxa associated with them, in both marine and freshwater environments; (ii) explore the key ecological factors shaping these diatom assemblages; and (iii) reassess critically the commonly applied concept of commensalism in epibiont-host relationships. Our literature review revealed that most research has been focused on charismatic basibiont groups, especially Chordata (notably Testudines and Cetacea), followed by Arthropoda and Mollusca, while taxa such as Bryozoa, Porifera, Cnidaria, Echinodermata, and Annelida have received far less attention. Most studies were carried out in marine settings, particularly in the Americas, and the number of publications has increased since the early 2000s. Taxonomic data on diatom communities shows that the genera Navicula, Nitzschia, Cocconeis and Amphora are the most frequently found as epizoic diatoms. In some cases, highly host-specific diatoms have been documented, for example Pseudohimantidium pacificum, Protoraphis atlantica, Falcula hyalina, and Sceptronema orientale on copepods. From a functional point of view, 'motile' diatoms were dominant on Chordata, Mollusca, and Arthropoda, followed by the 'high-profile' ecological guild. This dominance suggests active interaction between the organisms, supporting the development of well-structured communities on the hosts. There are several types of interaction, depending on the host and epibiont considered. We propose the concepts of triggers and drivers as a framework to describe the initial diversity and development of the epibiont community on the host, and we interpret the nature of these relationships as falling along a continuum from commensalism to parasitism and mutualism. Although diatoms are considered valuable tools for environmental monitoring, we suggest that host displacement and interactions with substrates may be considered as limiting factors for the use of epizoic diatoms in environmental monitoring. However, they may provide useful insights into host ecology, such as the range of host displacement and habits, feeding behaviour, and ecological traits, helping to clarify the trophic and behavioural interactions among basibionts and epibionts. This integrative perspective enhances our understanding of both diatom dispersal and their ecological tolerance and adaptability across diverse environmental contexts.