Philosophical Transactions of the Royal Society B: Biological Sciences最新文献

Conservation strategies seek to ensure that populations persist and are resilient to environmental change. As learning from others can shape the development of skills that help animals survive, reproduce and respond to changing conditions, understanding social learning can be of crucial conservation importance. Research on mammals, with their great diversity of niches and social systems, provides vital evidence that social learning helps animals to communicate, secure mates, avoid predators, forage effectively and navigate through their ecological and social environments. However, these environments are being rapidly altered in the Anthropocene, influencing individuals' reliance on social learning, the value of learned information, its spread through groups and the stability of socially learned traditions. Here, we review and synthesize this growing body of literature to highlight how understanding the ways in which animals use social learning and deploy it flexibly throughout their lives may enhance conservation programmes. We consider both the potential negative consequences of social learning and the scope for social-learning-driven interventions to generate adaptive responses to the challenges of rapidly changing environments. A greater appreciation and integration of social learning and its flexibility will ultimately promote the effective conservation of mammals and other taxa in our fast-changing world.This article is part of the theme issue 'Animal culture: conservation in a changing world'.

Social learning, information transmission and culture play vital roles in the lives of social animals, influencing their survival, reproduction and ability to adapt to changing environments. However, the effect of anthropogenic disturbances on these processes is poorly understood in free-living animals. To investigate the impact of anthropogenic disturbance on social learning and information transmission, we simulated individual removal from contact networks derived from long-term behavioural datasets. We simulate the effects of individual removal on network efficiency and social learning for three group-living species-yellow baboons (Papio cynocephalus), African savanna elephants (Loxodonta africana) and Indo-Pacific bottlenose dolphins (Tursiops aduncus). We reveal how removals of key network positions reduce network efficiency. However, groups with high levels of innovation may cope with changing social network structures. These findings highlight the importance of protecting key individuals to preserve group structure and the role of innovation in possibly mitigating the fitness costs of removals. Identifying and safeguarding individuals that drive innovation can reduce a group's susceptibility to anthropogenic threats and promote cultural resilience in social animals in a changing world. These emerging trends contribute to a growing understanding of the role of conservation interventions in protecting critical individuals in group-living animals.This article is part of the theme issue 'Animal culture: conservation in a changing world'.

The crowing of the male chicken is a charismatic example of vocal display in a bird. It is regarded as the main territorial announcement of the ancestral red junglefowl. The call has been preserved throughout domestication, although several of its elements have been altered. To assess these alterations, we assayed crowing spectrograms from wild and captive-held red junglefowl populations from India, along with two red junglefowl populations held in long-term captivity in Sweden, and a domestic white Leghorn breed. We find consistent differences between the different Indian red junglefowl and the domestic white Leghorn for a range of characteristics, including the duration of the last syllable and the number of formants and their frequency in the last and second-to-last syllable. To analyse the genetic architecture of crowing vocalization, we performed a quantitative trait loci (QTL) experiment using a wild × domestic advanced intercross to identify QTL that explained a large percentage of the variation present for the duration of the last syllable and the number of formants in the second to last syllable. With this study we thus demonstrate consistent differences in red junglefowl and white Leghorn chickens and identify a relatively simple genetic architecture for some of these traits.This article is part of the theme issue 'Unravelling domestication: multi-disciplinary perspectives on human and non-human relationships in the past, present and future'.

Two commensal pathways to plant domestication-ruderal and segetal-have been proposed. These domestication pathways are detailed here, together with associated archaeobotanical morphometric data for multiple crops within each pathway. The ruderal pathway characterizes how plants adapted to anthropically disturbed habitats, which can be associated with foraging or farming communities, were domesticated by people. Ruderal crops discussed are squash (Cucurbita pepo), aji chili (Capsicum baccatum) and melon (Cucumis melo). The segetal pathway characterizes how weeds in agricultural contexts became crops. Segetal crops discussed are rye (Secale cereale) and kodo millet (Paspalum scrobiculatum). Metric archaeobotanical datasets are used to infer the domestication episode for crops and to calculate rates of change in domestication traits (Haldanes). Although metric archaeobotanical data limits presentation and discussion to seeds, it enables quantitative comparisons of domestication episodes and haldane rates with those of the grain and fruit tree domestication pathways, respectively. We conclude that early ruderals underwent slower domestication processes, whereas segetals and perhaps some later ruderals, underwent faster processes of domestication that probably involved conscious selection.This article is part of the theme issue 'Unravelling domestication: multi-disciplinary perspectives on human and non-human relationships in the past, present and future'.

Stable isotopes provide insights into the early history of rye cultivation from the Migration period to the late Medieval period (fourth to fifteenth centuries CE). Manuring shows high intensity and diversity throughout. Rye as an undemanding crop resistant to drought was cultivated on nutrient-poor sandy soils to a limited extent only. It became a dominant crop owing to its integration into an existing labour-intensive manuring system mainly based on stable dung. Modern experiments demonstrate that the effect of manuring on cereal δ¹⁵N is strongly mediated by the soil substrate. Conspicuously low δ³⁴S values can indicate additional manuring with peat. The Δ¹³C values suggest that the best harvests were achieved on dwelling mounds close to the sea and that relatively poor harvests resulted on fields on dry, sandy soils. Because the mounds were flooded with salt water during winter storm surges, the crop cultivated there might have been summer rye. Winter rye became the dominant crop in Germany around 1000 CE and continued to be until the mid-twentieth century. Intensive manuring allowed for high yields, which facilitated the emergence of village communities and towns and stable political and religious power systems.This article is part of the theme issue 'Unravelling domestication: multi-disciplinary perspectives on human and non-human relationships in the past, present and future'.

The domestication of grain crops is among the most important phenomena to facilitate humanity's cultural development, and seed size increases are taken as one of the earliest domestication traits. Much remains unknown about the ecological drivers and cultural mechanisms surrounding this trait, but morphometric analyses have been crucial to investigate the topic for decades. Measurements on ancient cereal grains show that they evolved to produce larger seeds in their region of origin prior to dispersing beyond their progenitor range. This paper takes a transcontinental (Europe and Asia), long-term approach to comparative morphometric data. Unpublished measurements from over 10 sites of barley, free-threshing wheat, broomcorn millet, and foxtail millet from Central Asia and China have been collected for this study. We have contrasted these with published data from Europe, southwest and Central, East and South Asia. We investigate whether these cereals evolved in parallel or divergent ways across different lineages after they dispersed from their centres of origin; we trace seed size changes from initial cultivation through their spread and eventual adaptation to novel environments. This comparative analysis allows us to discuss rates of evolution and highlight evolutionary trends within some of the most important cereal crops across the Eurasian continent.This article is part of the theme issue 'Unravelling domestication: multi-disciplinary perspectives on human and non-human relationships in the past, present and future'.

Animal vocalizations comprise a rich array of complex sounds that exhibit nonlinear phenomena (NLP), which have fascinated researchers for decades. From the melodic songs of birds to the clicks and whistles of dolphins, many species have been found to produce nonlinear vocalizations, offering a valuable perspective on the mechanisms underlying sound production and potential adaptive functions. By leveraging on the principles of oscillator theory and nonlinear dynamics, animal vocalizations, which are based on coupled oscillators, can be described and conveniently classified. We review the basic ingredients for self-sustained oscillations and how different NLP can emerge. We discuss important terms in the context of oscillator theory: attractor types, phase space, bifurcations and Arnold tongue diagrams. Through a comparative analysis of observed NLP and bifurcation diagrams, our study reviews how the tools of nonlinear dynamics can provide insights into the intricate complexity of animal vocalizations, as well as into the evolutionary pressures and adaptive strategies that have shaped the diverse communication systems of the animal kingdom.This article is part of the theme issue, 'Nonlinear phenomena in vertebrate vocalizations: mechanisms and communicative functions'.

We address two research applications in this methodological review: starting from an audio recording, the goal may be to characterize nonlinear phenomena (NLP) at the level of voice production or to test their perceptual effects on listeners. A crucial prerequisite for this work is the ability to detect NLP in acoustic signals, which can then be correlated with biologically relevant information about the caller and with listeners' reaction. NLP are often annotated manually, but this is labour-intensive and not very reliable, although we describe potentially helpful advanced visualization aids such as reassigned spectrograms and phasegrams. Objective acoustic features can also be useful, including general descriptives (harmonics-to-noise ratio, cepstral peak prominence, vocal roughness), statistics derived from nonlinear dynamics (correlation dimension) and NLP-specific measures (depth of modulation and subharmonics). On the perception side, playback studies can greatly benefit from tools for directly manipulating NLP in recordings. Adding frequency jumps, amplitude modulation and subharmonics is relatively straightforward. Creating biphonation, imitating chaos or removing NLP from a recording are more challenging, but feasible with parametric voice synthesis. We describe the most promising algorithms for analysing and manipulating NLP and provide detailed examples with audio files and R code in supplementary material.This article is part of the theme issue 'Nonlinear phenomena in vertebrate vocalizations: mechanisms and communicative functions'.

Nonlinear phenomena (NLP) are acoustic irregularities that are widespread in animal and human vocal repertoires, as well as in music. These phenomena have recently attracted considerable interest but, surprisingly, have never been the subject of a comprehensive review. NLP result from irregular sound production, contribute to perceptual harshness, and have long been considered nonadaptive vocal features or by-products of sound production characterizing pathological voices. This view is beginning to change: NLP are increasingly documented in nonverbal vocalizations of healthy humans, and an impressive variety of acoustic irregularities are found in the vocalizations of nonhuman vertebrates. Indeed, evidence is accumulating that NLP have evolved to serve specific functions such as attracting listeners' attention, signalling high arousal, or communicating aggression, size, dominance, distress and/or pain. This special issue presents a selection of theoretical and empirical studies showcasing novel concepts and analysis tools to address the following key questions: How are NLP in vertebrate vocalizations defined and classified? What are their biomechanical origins? What are their communicative functions? How and why did they evolve? We also discuss the broader significance and societal implications of research on NLP for non-invasively monitoring and improving human and animal welfare.This article is part of the theme issue 'Nonlinear phenomena in vertebrate vocalizations: mechanisms and communicative functions'.

At some point in our evolutionary history, humans lost vocal membranes and air sacs, representing an unexpected simplification of the vocal apparatus relative to other great apes. One hypothesis is that these simplifications represent anatomical adaptations for speech because a simpler larynx provides a suitably stable and tonal vocal source with fewer nonlinear vocal phenomena (NLP). The key assumption that NLP reduce speech intelligibility is indirectly supported by studies of dysphonia, but it has not been experimentally tested. Here, we manipulate NLP in vocal stimuli ranging from single vowels to sentences, showing that the vocal source needs to be stable, but not necessarily tonal, for speech to be readily understood. When the task is to discriminate synthesized monophthong and diphthong vowels, continuous NLP (subharmonics, amplitude modulation and even deterministic chaos) actually improve vowel perception in high-pitched voices, likely because the resulting dense spectrum reveals formant transitions. Rough-sounding voices also remain highly intelligible when continuous NLP are added to recorded words and sentences. In contrast, voicing interruptions and pitch jumps dramatically reduce speech intelligibility, likely by interfering with voicing contrasts and normal intonation. We argue that NLP were not eliminated from the human vocal repertoire as we evolved for speech, but only brought under better control.This article is part of the theme issue 'Nonlinear phenomena in vertebrate vocalizations: mechanisms and communicative functions'.