abstract：:Placoderms are a diverse group of armoured fishes that dominated the aquatic ecosystems of the Devonian Period, 415-360 million years ago. The bladed jaws of predators such as Dunkleosteus suggest that these animals were the first vertebrates to use rapid mouth opening and a powerful bite to capture and fragment evasi...

journal_title：Biology letters

authors： Anderson PS,Westneat MW

更新日期：2007-02-22 00:00:00

abstract：:Males of a variety of taxa occasionally steal food secured by their mates. In some spiders and insects, males rely entirely on this form of intraspecific kleptoparasitism for their subsistence. However, this male strategy may be costly for females and a variety of different female counteradaptations have been proposed...

journal_title：Biology letters

authors： Arnqvist G,Jones TM,Elgar MA

更新日期：2006-12-22 00:00:00

abstract：:Numerous species undergo impressive movements, but due to massive changes in land use, long distance migration in terrestrial vertebrates has become a highly fragile ecological phenomenon. Uncertainty about the locations of past migrations and the importance of current corridors hampers conservation planning. Using ar...

journal_title：Biology letters

authors： Berger J,Cain SL,Berger KM

更新日期：2006-12-22 00:00:00

abstract：:Sex ratio evolution relies on genetic variation in either the phenotypic traits that influence sex ratios or sex-determining mechanisms. However, consistent variation among females in offspring sex ratio is rarely investigated. Here, we show that female painted dragons (Ctenophorus pictus) have highly repeatable sex r...

journal_title：Biology letters

authors： Uller T,Mott B,Odierna G,Olsson M

更新日期：2006-12-22 00:00:00

abstract：:Two non-coding DNA classes, introns and intergenic regions, of Drosophila melanogaster exhibit contrasting evolutionary patterns. GC content is significantly higher in intergenic regions and affects their degree of nucleotide variability. Divergence is positively correlated with recombination rate in intergenic region...

journal_title：Biology letters

authors： Ometto L,De Lorenzo D,Stephan W

更新日期：2006-12-22 00:00:00

abstract：:Avian predators learn to avoid defended insects on the basis of their conspicuous warning coloration. In many aposematic species, the level of chemical defence varies, with some individuals being more defended than others. Sequestration and production of defence chemicals is often costly and therefore less defended in...

journal_title：Biology letters

authors： Skelhorn J,Rowe C

更新日期：2006-09-22 00:00:00

abstract：:In cooperative animal societies, dominant females typically show higher breeding success than subordinates, and are commonly believed to control the extent of reproductive sharing. However, studies of social insect societies reveal that subordinates too can interfere with the breeding attempts of others, with importan...

journal_title：Biology letters

authors： Young AJ,Clutton-Brock T

更新日期：2006-09-22 00:00:00

abstract：:The phenomenon of endocrine disruption is currently a source of growing concern. Feminization of male fish in UK rivers has been shown to occur extensively and has been linked with exposure to endocrine-disrupting compounds present in the environment. Much less is known of the extent and scale of endocrine disruption ...

journal_title：Biology letters

authors： Chesman BS,Langston WJ

更新日期：2006-09-22 00:00:00

abstract：:Mycobacterium bovis is the causative agent of bovine tuberculosis (bTB) in cattle and wildlife. Direct aerosol contact is thought to be the primary route of infection between conspecifics, whereas indirect transmission via an environmental reservoir of M. bovis is generally perceived not to be a significant source for...

journal_title：Biology letters

authors： Courtenay O,Reilly LA,Sweeney FP,Hibberd V,Bryan S,Ul-Hassan A,Newman C,Macdonald DW,Delahay RJ,Wilson GJ,Wellington EM

更新日期：2006-09-22 00:00:00

abstract：:The relationship between algae and their zooplanktonic predators typically involves consumption of nutrients by algae, grazing of the algae by zooplankton which in turn enhances predator biomass, controls algal growth and regenerates nutrients. Eutrophication raises nutrient levels, but does not simply increase normal...

journal_title：Biology letters

authors： Mitra A,Flynn KJ

更新日期：2006-06-22 00:00:00

abstract：:Negative effects of inbreeding are well documented in a wide range of animal taxa. Hatching success and survival of inbred offspring is reduced in many species and inbred progeny are often less attractive to potential mates. Thus, individuals should avoid mating with close kin. However, experimental evidence for inbre...

journal_title：Biology letters

authors： Frommen JG,Bakker TC

更新日期：2006-06-22 00:00:00

abstract：:The associations between habitat and other factors that lead to the risk of bovine tuberculosis (bTB) in diary cattle were examined in an unmatched case-control study. Data from 60 herds with recent history of bTB and 60 controls were analysed using logistic regression. The predictors included farmland habitat, topogr...

journal_title：Biology letters

authors： Mathews F,Lovett L,Rushton S,Macdonald DW

更新日期：2006-06-22 00:00:00

abstract：:Anthropogenic impacts are believed to be the primary threats to the eastern Australian population of grey nurse sharks (Carcharias taurus), which is listed as critically endangered, and the most threatened population globally. Analyses of 235 polymorphic amplified fragment length polymorphisms (AFLP) loci and 700 base...

journal_title：Biology letters

authors： Stow A,Zenger K,Briscoe D,Gillings M,Peddemors V,Otway N,Harcourt R

更新日期：2006-06-22 00:00:00

abstract：:Plain-tailed wrens (Thryothorus euophrys) live in groups that sing synchronized choruses, the contributions of females and males alternating with each other in cycles, within which each sex sings two of the four parts, the whole achieving near perfect synchrony. As each bird has a repertoire of ca 20 phrases of each t...

journal_title：Biology letters

authors： Mann NI,Dingess KA,Slater PJ

更新日期：2006-03-22 00:00:00

abstract：:This study reports the first experimental exploration of possible contagious yawning in monkeys. Twenty-two stumptail macaques (Macaca arctoides) were presented with video clips of either yawns or control mouth movements by conspecifics. At a group level, monkeys yawned significantly more often during and just after t...

journal_title：Biology letters

authors： Paukner A,Anderson JR

更新日期：2006-03-22 00:00:00

abstract：:The fauna of ancient lakes frequently contains taxa with highly derived morphologies that resulted from in situ radiation of lacustrine lineages with high antiquity. We employed a molecular mtDNA phylogeny to investigate this claim for corbiculid freshwater bivalves in two ancient lake systems on the Indonesian island...

journal_title：Biology letters

authors： von Rintelen T,Glaubrecht M

更新日期：2006-03-22 00:00:00

abstract：:Dromaeosaurid theropod dinosaurs possess a strongly recurved, hypertrophied and hyperextensible ungual claw on pedal digit II. This feature is usually suggested to have functioned as a device for disembowelling herbivorous dinosaurs during predation. However, modelling of dromaeosaurid hindlimb function using a roboti...

journal_title：Biology letters

authors： Manning PL,Payne D,Pennicott J,Barrett PM,Ennos RA

更新日期：2006-03-22 00:00:00

abstract：:Migratory animals present a unique challenge for predicting population size because they are influenced by events in multiple stages of the annual cycle that are separated by large geographic distances. Here, we develop a model that incorporates non-fatal carry-over effects to predict changes in population size and sh...

journal_title：Biology letters

authors： Norris DR,Taylor CM

更新日期：2006-03-22 00:00:00

abstract：:Research on reproductive isolation in African cichlid fishes has largely focused on the role of nuptial colours, but other sensory modes may play an important role in mate choice. Here, we compare the relative importance of visual and olfactory cues in mate recognition by females of a Lake Malawi cichlid species. Fema...

journal_title：Biology letters

authors： Plenderleith M,van Oosterhout C,Robinson RL,Turner GF

更新日期：2005-12-22 00:00:00

abstract：:Patterns of population genetic variation have frequently been understood as consequences of life history covariates such as dispersal ability and breeding systems (e.g. selfing). For example, marine invertebrates show enormous variation in life history traits that are correlated with the extent of gene flow between po...

journal_title：Biology letters

authors： Addison JA,Hart MW

更新日期：2005-12-22 00:00:00

abstract：:Infection density is among the most important factors for understanding the biological effects of Wolbachia and other endosymbionts on their hosts. To gain insight into the mechanisms of infection density regulation, we investigated the adzuki bean beetles Callosobruchus chinensis and their Wolbachia endosymbionts. Do...

journal_title：Biology letters

authors： Kondo N,Shimada M,Fukatsu T

更新日期：2005-12-22 00:00:00

abstract：:There is increasing evidence from non-human animals that males adjust their ejaculate expenditure according to the risk of sperm competition. In this study we show that, after controlling for lifestyle factors known to influence semen quality, human males viewing images depicting sperm competition had a higher percent...

journal_title：Biology letters

authors： Kilgallon SJ,Simmons LW

更新日期：2005-09-22 00:00:00

abstract：:Twenty years ago, the field of ancient DNA was launched with the publication of two short mitochondrial (mt) DNA sequences from a single quagga (Equus quagga) museum skin, an extinct South African equid (Higuchi et al. 1984 Nature312, 282-284). This was the first extinct species from which genetic information was retr...

journal_title：Biology letters

authors： Leonard JA,Rohland N,Glaberman S,Fleischer RC,Caccone A,Hofreiter M

更新日期：2005-09-22 00:00:00

abstract：:Although the presence of feathers in the nest is widespread among birds, it has not been previously suggested that feathers can be used as sexual signals. Females of the spotless starling (Sturnus unicolor) regularly carry feathers to their nest, mostly during laying and incubation. We show that the arrangement of the...

journal_title：Biology letters

authors： Veiga JP,Polo V

更新日期：2005-09-22 00:00:00

abstract：:Male sand lizards (Lacerta agilis) with a specific restriction fragment length polymorphism fragment in their major histocompatibility complex (MHC) genotype ('O-males') are more resistant to ectoparasites (a tick, Ixodes ricinus) than are males that lack this fragment ('NO-males'). However, emerging evidence suggests...

journal_title：Biology letters

authors： Olsson M,Wapstra E,Madsen T,Ujvari B,Rugfelt C

更新日期：2005-09-22 00:00:00

abstract：:The mid-domain effect (MDE), a bias in species richness towards the midpoint of a given geographical dimension, has been used as a null model in macro-ecological studies. Departures from a MDE are often thought of as interesting. The MDE is a product of the interaction between geometric boundaries and range locations,...

journal_title：Biology letters

authors： Davies TJ,Grenyer R,Gittleman JL

更新日期：2005-06-22 00:00:00

abstract：:Prolific polyembryony is reported in few major taxa, but its occurrence has generated theoretical debate on potential conflict between sexual and asexual reproduction. It is, therefore, important to genetically confirm a widely cited inference, based on microscopy, that polyembryony characterizes marine bryozoans of t...

journal_title：Biology letters

authors： Hughes RN,D'Amato ME,Bishop JD,Carvalho GR,Craig SF,Hansson LJ,Harley MA,Pemberton AJ

更新日期：2005-06-22 00:00:00

abstract：:Evidence of altered primary sex ratios in birds shows that mothers can manipulate the sex of their offspring before oviposition. In birds, females are the heterogametic sex (ZW) and males are homogametic (ZZ). Sex is determined in the first meiotic division, when one sex chromosome is retained in the oocyte and the ot...

journal_title：Biology letters

authors： Correa SM,Adkins-Regan E,Johnson PA

更新日期：2005-06-22 00:00:00

abstract：:Flight feather moult in small passerines is realized in several ways. Some species moult once after breeding or once on their wintering grounds; others even moult twice. The adaptive significance of this diversity is still largely unknown. We compared the resistance to mechanical fatigue of flight feathers from the ch...

journal_title：Biology letters

authors： Weber TP,Borgudd J,Hedenström A,Persson K,Sandberg G

更新日期：2005-03-22 00:00:00

abstract：:Spatial and temporal heterogeneity in relative fitness of competing species is a key factor affecting the structure of communities. However, it is not intuitive why species that are ecologically similar should differ in their response to environmental changes. Here we show that two sympatric flycatchers differ in repr...

journal_title：Biology letters

authors： Qvarnström A,Svedin N,Wiley C,Veen T,Gustafsson L

更新日期：2005-03-22 00:00:00

abstract：:Coevolution with parasites is thought to maintain genetic diversity in host populations. However, while there are sound theoretical reasons to expect heterozygosity and parasite resistance to be related, this pattern has generally been shown only in inbred laboratory and island populations. This leaves doubt as to whe...

journal_title：Biology letters

authors： MacDougall-Shackleton EA,Derryberry EP,Foufopoulos J,Dobson AP,Hahn TP

更新日期：2005-03-22 00:00:00