Biological Reviews of the Cambridge Philosophical Society

Hydropeaking refers to frequent, rapid and short-term fluctuations in water flow and water levels downstream and upstream of hydropower stations. Such fluctuations are becoming increasingly common worldwide and are known to have far-reaching effects on riverine vegetation. Novel hydrology caused by hydropeaking has no natural correspondence in freshwater systems, and hence few species have adaptations to all its aspects. Here, we review the literature on hydropeaking effects on riverine plants and define the state of the information on this human alteration of riverine ecosystems...

Species flocks (SFs) fascinate evolutionary biologists who wonder whether such striking diversification can be driven by normal evolutionary processes. Multiple definitions of SFs have hindered the study of their origins. Previous studies identified a monophyletic taxon as a SF if it displays high speciosity in an area in which it is endemic (criterion 1), high ecological diversity among species (criterion 2), and if it dominates the habitat in terms of biomass (criterion 3); we used these criteria in our analyses...

Bone remodelling is a continuous process by which bone resorption by osteoclasts is followed by bone formation by osteoblasts to maintain skeletal homeostasis. These two forces must be tightly coordinated not only quantitatively, but also in time and space, and its malfunction leads to diseases such as osteoporosis. Recent research focusing on the cross-talk and coupling mechanisms associated with the sequential recruitment of osteoblasts to areas where osteoclasts have removed bone matrix have identified a number of osteogenic factors produced by the osteoclasts themselves...

Endocrine-disrupting chemicals (EDCs) can alter biological function in organisms at environmentally relevant concentrations and are a significant threat to aquatic biodiversity, but there is little understanding of exposure consequences for populations, communities and ecosystems. The pervasive nature of EDCs within aquatic environments and their multiple sub-lethal effects make assessments of their impact especially important but also highly challenging. Herein, we review the data on EDC effects in aquatic systems focusing on studies assessing populations and ecosystems, and including how biotic and abiotic processes may affect, and be affected by, responses to EDCs...

Dispersal is a process of central importance for the ecological and evolutionary dynamics of populations and communities, because of its diverse consequences for gene flow and demography. It is subject to evolutionary change, which begs the question, what is the genetic basis of this potentially complex trait? To address this question, we (i) review the empirical literature on the genetic basis of dispersal, (ii) explore how theoretical investigations of the evolution of dispersal have represented the genetics of dispersal, and (iii) discuss how the genetic basis of dispersal influences theoretical predictions of the evolution of dispersal and potential consequences...

Much biodiversity data is collected worldwide, but it remains challenging to assemble the scattered knowledge for assessing biodiversity status and trends. The concept of Essential Biodiversity Variables (EBVs) was introduced to structure biodiversity monitoring globally, and to harmonize and standardize biodiversity data from disparate sources to capture a minimum set of critical variables required to study, report and manage biodiversity change. Here, we assess the challenges of a 'Big Data' approach to building global EBV data products across taxa and spatiotemporal scales, focusing on species distribution and abundance...

Basal rate of metabolism (BMR) is a physiological parameter that should be measured under strictly defined experimental conditions. In comparative analyses among mammals BMR is widely used as an index of the intensity of the metabolic machinery or as a proxy for energy expenditure. Many databases with BMR values for mammals are available, but the criteria used to select metabolic data as BMR estimates have often varied and the potential effect of this variability has rarely been questioned. We provide a new, expanded BMR database reflecting compliance with standard criteria (resting, postabsorptive state; thermal neutrality; adult, non-reproductive status for females) and examine potential effects of differential selectivity on the results of comparative analyses...

We propose an evolutionary perspective to classify and characterize the diverse systems of adaptive immunity that have been discovered across all major domains of life. We put forward a new function-based classification according to the way information is acquired by the immune systems: Darwinian immunity (currently known from, but not necessarily limited to, vertebrates) relies on the Darwinian process of clonal selection to 'learn' by cumulative trial-and-error feedback; Lamarckian immunity uses templated targeting (guided adaptation) to internalize heritable information on potential threats; finally, shotgun immunity operates through somatic mechanisms of variable targeting without feedback...

Evolutionary theory predicts competition in nature yet altruistic and cooperative behaviour appears to reduce the ability to compete in order to help others compete better. This evolutionary puzzle is usually explained by kin selection where close relatives perform altruistic and cooperative acts to help each other and by reciprocity theory (i.e. direct, indirect and generalized reciprocity) among non-kin. Here, it is proposed that the concepts of asymmetry and symmetry in power and dominance are critical if we are ever to resolve the puzzle of altruism and cooperation towards non-kin...

Forest ecosystems are critical to mitigating greenhouse gas emissions through carbon sequestration. However, climate change has affected forest ecosystem functioning in both negative and positive ways, and has led to shifts in species/functional diversity and losses in plant species diversity which may impair the positive effects of diversity on ecosystem functioning. Biodiversity may mitigate climate change impacts on (I) biodiversity itself, as more-diverse systems could be more resilient to climate change impacts, and (II) ecosystem functioning through the positive relationship between diversity and ecosystem functioning...

This review covers the field of olfaction and chemosensation of odorants and puts this information into the context of interactions between microbes and behaviour; the microbiome-gut-brain axis (MGBA). Recent emphasis has also been placed on the concept of the holobiome which states that no single aspect of an organism should be viewed separately and thus must include examination of their associated microbial populations and their influence. While it is known that the microbiome may be involved in the modulation of animal behaviour, there has been little systematized effort to incorporate into such studies the rapidly developing knowledge of the wide range of olfactory systems...

The loss of functional β cells leads to development of diabetes. Several studies have shown that β cells are specified through several stages of progenitors during pancreas development, each stage defined by the expression of specific transcription factors (TFs). Understanding signalling pathways that control the differentiation and specification processes during embryogenesis will facilitate efforts to obtain functional β cells in vitro. Our current knowledge of the mechanisms involved in pancreatic β cell development and survival under normal or diabetic conditions has come largely from animal studies...

The respiratory chain of mitochondria and bacteria is made up of a set of membrane-associated enzyme complexes which catalyse sequential, stepwise transfer of reducing equivalents from substrates to oxygen and convert redox energy into a transmembrane protonmotive force (PMF) by proton translocation from a negative (N) to a positive (P) aqueous phase separated by the coupling membrane. There are three basic mechanisms by which a membrane-associated redox enzyme can generate a PMF. These are membrane anisotropic arrangement of the primary redox catalysis with: (i) vectorial electron transfer by redox metal centres from the P to the N side of the membrane; (ii) hydrogen transfer by movement of quinones across the membrane, from a reduction site at the N side to an oxidation site at the P side; (iii) a different type of mechanism based on co-operative allosteric linkage between electron transfer at the metal redox centres and transmembrane electrogenic proton translocation by apoproteins...

Bone formation, for example during bone remodelling or fracture repair, requires mature osteoblasts to deposit bone with remarkable spatial precision. As osteoblast precursors derive either from circulation or resident stem cell pools, they and their progeny are required to migrate within the three-dimensional bone space and to navigate to their destination, i.e. to the site of bone formation. An understanding of this process is emerging based on in vitro and in vivo studies of several vertebrate species. Receptors on the osteoblast surface mediate cell adhesion and polarization, which induces osteoblast migration...

Ecological studies are increasingly moving towards trait-based approaches, as the evidence mounts that functions, as opposed to taxonomy, drive ecosystem service delivery. Among ecosystem services, biological control has been somewhat overlooked in functional ecological studies. This is surprising given that, over recent decades, much of biological control research has been focused on identifying the multiple characteristics (traits) of species that influence trophic interactions. These traits are especially well developed for interactions between arthropods and flowers - important for biological control, as floral resources can provide natural enemies with nutritional supplements, which can dramatically increase biological control efficiency...

Climate change is driving a pervasive global redistribution of the planet's species. Species redistribution poses new questions for the study of ecosystems, conservation science and human societies that require a coordinated and integrated approach. Here we review recent progress, key gaps and strategic directions in this nascent research area, emphasising emerging themes in species redistribution biology, the importance of understanding underlying drivers and the need to anticipate novel outcomes of changes in species ranges...

We synthesize findings from one of the world's largest and longest-running experimental investigations, the Biological Dynamics of Forest Fragments Project (BDFFP). Spanning an area of ∼1000 km(2) in central Amazonia, the BDFFP was initially designed to evaluate the effects of fragment area on rainforest biodiversity and ecological processes. However, over its 38-year history to date the project has far transcended its original mission, and now focuses more broadly on landscape dynamics, forest regeneration, regional- and global-change phenomena, and their potential interactions and implications for Amazonian forest conservation...

An exhaustive study of existing data on the relationship between egg size and maximum size of embryonic shells in 42 species of extant cephalopods demonstrated that these values are approximately equal regardless of taxonomy and shell morphology. Egg size is also approximately equal to mantle length of hatchlings in 45 cephalopod species with rudimentary shells. Paired data on the size of the initial chamber versus embryonic shell in 235 species of Ammonoidea, 46 Bactritida, 13 Nautilida, 22 Orthocerida, 8 Tarphycerida, 4 Oncocerida, 1 Belemnoidea, 4 Sepiida and 1 Spirulida demonstrated that, although there is a positive relationship between these parameters in some taxa, initial chamber size cannot be used to predict egg size in extinct cephalopods; the size of the embryonic shell may be more appropriate for this task...

Humpback whales (Megaptera novaeangliae) are seasonal breeders, annually migrating from high-latitude summer feeding grounds to low-latitude winter breeding grounds. The social matrix on the winter grounds is a loose network of interacting individuals and groups and notably includes lone males that produce long bouts of complex song that collectively yield an asynchronous chorus. Occasionally, a male will sing while accompanying other whales. Despite a wealth of knowledge about the social matrix, the full characterization of the mating system remains unresolved, without any firm consensus, as does the function of song within that system...

Considering the properties of mirror neurons (MNs) in terms of development and phylogeny, we offer a novel, unifying, and testable account of their evolution according to the available data and try to unify apparently discordant research, including the plasticity of MNs during development, their adaptive value and their phylogenetic relationships and continuity. We hypothesize that the MN system reflects a set of interrelated traits, each with an independent natural history due to unique selective pressures, and propose that there are at least three evolutionarily significant trends that gave raise to three subtypes: hand visuomotor, mouth visuomotor, and audio-vocal...