Proceedings of the Royal Society B: Biological Sciences
First-ever observations of a live giant squid in the wild by Dr. T Kubodera and Dr. K Mori (rspb.2005.3158) The giant squid, Architeuthis, is one of the most mysterious creatures in the deep-sea. This is the first-ever successful attempt to observe a live giant squid in the wild. Not only can we provide the first live images of Architeuthis, but we have also reported on the only data on the depth and behaviour of this species. The observed giant squid was estimated about 8 m in total length, and hunting at 900 m depth during the day. It attacked prey from a horizontal orientation with a pair of long tentacles and enveloped the prey within coiled tentacular ball.
Contact: Dr. T Kubodera, National Science Museum, Tokyo, 3-23-1, Hyakunin-cho, TOKYO, 169-0073, Japan
Not so ancient: the extant crown group of Nothofagus represents a post-Gondwanan radiation by Dr LG Cook and Dr MD Crisp (rspb.2005.3219)
Nothofagus (southern beeches) have been considered the key group for understanding the distribution of plants and animals in the Southern Hemisphere for 150 years. These beeches were widespread across eastern Gondwana before the super-continent split up and most of their present-day distribution, separated by oceans, is thought to reflect that ancient connection. Using relaxed molecular clocks, calibrated with fossils, we have determined that much of the differentiation among present-day Nothofagus lineages took place after Gondwana broke up. Rather than being "ancient relicts", current species of Nothofagus appear to be the descendants of a single species that survived a major extinction.
Contact: Dr LG Cook, School of Botany and Zoology, Australian National University, Australia
The pathogen causing Dutch elm disease makes host trees attract insect vectors by Mr GD Mcleod, Ms RM Gries, Mr. SH von ReuB, Dr. JE Rahe, Dr. R McIntosh, Dr. WA Koenig and Professor G Gries (rspb.2005.3202)
The fungal pathogen Ophiostoma novo-ulmi kills American elm trees, and then requires transportation by elm bark beetles, Hylurgopinus rufipes, to new host elms. We have found that four semiochemicals (message-bearing chemicals) from diseased elms synergistically attract H. rufipes, and that their emission is up-regulated in elm trees inoculated with O. novo-ulmi. The pathogen thus manipulates host trees to enhance their apparency to foraging beetles, a strategy that increases the probability of transportation of the pathogen to new hosts. Our findings explain the rapid spread of Dutch elm disease in North America and provide opportunity for manipulation of vector beetle populations.
Contact: Mr GD Mcleod, Biological Sciences, Simon Fraser University, 8888 University Drive, BURNABY BC, V5A 1S6, Canada
Fear in animals: a meta-analysis and review of risk assessment by Mr. T Stankowich and Dr DT Blumstein (rspb.2005.3251)
Based on an extensive review and analysis of previous work spanning all animal groups, this study found that predator traits indicative of greater risk (increased approach speed, larger size, more directed approach), increased distance to safety, and experience with predators amplified the perception of risk in prey. While fish tolerated closer approach when in larger schools, other types of animals fled at greater distances when in larger groups. Animals possessing armor or cryptic coloration also had a decreased perception of risk. We find that selection sensitizes prey to predator behaviour, and prey can reduce fear via behavioural modifications and experience.
Contact: Mr. T Stankowich, University of California, Davis, 268A Young Hall, DAVIS, 95616, United States
Sex and segregation in temperate bats by Miss P Senior, Professor RK Butlin and Professor JD Altringham (rspb.2005.3237)
At cave entrances throughout the temperate world, thousands of bats gather on late summer nights. This is when many bats mate, just before their winter hibernation. Females store and nourish sperm, delaying pregnancy until the spring. In the summer dominant male Daubenton's bats share better lowland habitat with nursing females. We show that this strategy enables the fittest males to father most of the offspring, probably by mating with females after their young have flown, but before swarming. This may give their sperm the first class accommodation in the oviduct through the winter.
Contact: Professor JD Altringham, School of Biology, University of Leeds, LEEDS, LS2 9JT
A candidate locus for variation in dispersal rate in a butterfly metapopulation by Dr CR Haag, Ms M Saastamoinen, Dr JH Marden and Professor IA Hanski (rspb.2005.3235)
Habitat loss and fragmentation increase the risk of local extinction of small populations. Species may nonetheless survive regionally if sufficient numbers of individuals disperse and establish new populations to compensate for extinctions. Here we show that dispersal ability in a butterfly species is related to genetic variation in a metabolic enzyme, and that those butterflies that disperse the longest distances are metabolically superior to those individuals that remain at their site of birth. These results provide a new understanding of how movement behaviour is influenced by the interaction between genetic variation and landscape structure.
Contact: Dr CR Haag, Institute of Evolutionary Biology, University of Edinburgh, King's Buildings, Ashworth Lab. 2, EDINBURGH, EH9 3JT
A Within-Species Warning Function for an Aposematic Signal by Dr. DR Papaj and Ms. GM Newsom (rspb.2005.3186)
Aposematic, or warning, signals are signals are used by one species to advertise noxiousness to an enemy species such as a predator. In a study of the pipevine swallowtail butterfly (Battus philenor), a colour pattern in caterpillars known to be aposematic in terms of attack by natural enemies also deterred egg-laying by adult females. In field and laboratory, females avoided laying eggs on plants bearing live caterpillars. The same result was obtained using silicone models identical to caterpillars in shape, size and colour pattern. These results suggest that aposematic signals may have multiple functions.
Contact: Dr. DR Papaj, Ecology & Evolutionary Biology, University of Arizona, Biological Sciences West, Rm. 310, TUCSON, 85721, United States
Evolutionary implications of the adaptation to different immune systems in a parasite with a complex life cycle by Dipl. Biol. K Hammerschmidt and Dr J Kurtz (rspb.2005.3241)
Many parasites have life cycles that include several host species. Are such parasites able to cope equally well with the different immune systems of their host species? In a model system of a tapeworm and its intermediate hosts (a small crustacean and stickleback fish), we found that parasites that are highly infective towards the crustacean are also superior at evading innate immunity (i.e. the first line of defence) of the fish. Moreover, these highly infective parasites were less harmful to the fish. This shows that adaptation of a parasite to one host might influence how harmful it is to the other host species, which is important also for understanding the evolution of human parasites.
Contact: Dr J Kurtz, Ecology & Evolution, ETH Zurich, ETH Zentrum CHN J12.1, Universitatsstr. 16, ZURICH, 8092, Switzerland
Patterns of male sterility in a grasshopper hybrid zone imply accumulation of hybrid incompatibilities without selection by Dr DM Shuker, Dr K Underwood, Dr TM King and Professor RK Butlin (rspb.2005.3242)
How do separate populations of an organism become sufficiently different to become new species? This question is central to our understanding of how the process of forming new species, or speciation, works. Recent work from fruit flies has suggested that the differences between diverging populations are the result of natural selection, with new species forming as separate populations adapt to their surroundings. However, the changes could just be arbitrary and selectively neutral, arising by chance (or by "genetic drift"). We have studied two sub-species of the meadow grasshopper, Chorthippus parallelus (Fig. 1), which meet and form hybrids in the high valleys of the Pyrenees Mountains. We looked at the genetic basis of the hybrid male sterility that separates the two sub-species, and found that the patterns of genetic variation in sterility in the two populations were more likely to be explained by genetic drift than by natural selection. The way in which the hybrids share genes from the two pure sub-species in the hybrid zone also suggested that the genetic changes were not brought about by natural selection. Our data therefore suggest that natural selection may not always be necessary for the origin of new species.
Contact: Dr DM Shuker, Institute of Evolutionary Biology, School of Biological Sciences, University of Edinburgh, EDINBURGH, EH9 3JT
Strikingly variable divergence times inferred across an Amazonian butterfly 'suture zone' by Miss A Whinnett, Dr M Zimmermann, Dr KR Keith, Miss NL Herrera, Mr R Mallarino, Mr F Simpson, Dr M Joron, Dr G Lamas and Professor JLB Mallet (rspb.2005.3247)
It has been generally accepted that geographic isolation is necessary for the evolution of new species. The high diversity of species and subspecies in the Amazon basin may have been due to periods of drought during which the rainforest became fragmented, giving rise to geographic isolation, and hence evolution of new species in putative forest "refuges". We studied the evolution of mitochondrial DNA in ithomiine butterflies of the Peruvian Amazon rainforest. DNA evolves gradually, according to an approximate molecular clock, and DNA evolution therefore reveals the time-course of evolution.
Our study shows that rainforest refuges, if they ever existed, had different effects on each group of butterflies, or that there was little effect of geographic isolation. Some groups speciated rather slowly, over tens of millions of years, while others produced many species and subspecies over periods of one or two million years. These results suggest that speciation was driven mainly by particular features of the biology and ecology of each butterfly group, rather than by an overriding effect of geographic isolation affecting all species simultaneously.
Contact: Professor JLB Mallet, Biology (Galton Laboratory), UCL, 4 Stephenson Way, LONDON, NW1 2HE
Montane speciation patterns in Ithomiola butterflies (Lepidoptera: Riodinidae): are they consistently moving up in the World? by Dr JPW Hall (rspb.2005.3254)
A phylogeny was generated for all eleven species of the Neotropical riodinid butterfly genus Ithomiola, using morphological data, which was then used to reconstruct the geographic and elevational radiation of the group and test the prevalence of five different tropical montane speciation modes. Successively more derived species were generally found to occupy successively higher elevational bands, and the dominant mode of speciation was thus hypothesized to be vertical parapatric speciation across an elevational gradient. These data seem to support the hypothesis that relatively young species are predominantly evolving in montane areas and old species are mostly confined to the lowlands.
Contact: Dr JPW Hall, Entomology, Smithsonian, National Museum of Natural History, WASHINGTON, 20560-127, United States
Helpers benefit offspring in both the short and long-term in the cooperatively breeding banded mongoose by Dr SJ Hodge (rspb.2005.3255)
In some animal societies group members care for offspring that are not their own. Explanations for this unusual behaviour centre around the assumption that offspring benefit from the efforts of helpers, but this has proved surprisingly difficult to show due to factors that confound comparisons across litters. Using data from a three year study of wild banded mongooses, I show that offspring that receive more care grow faster, survive better and breed earlier than their littermates. This evidence is unusually strong because banded mongoose offspring vary markedly in the amount of care that they receive, providing a rare opportunity to compare pups within litters.
Contact: Dr SJ Hodge, Dept of Zoology, University of Cambridge, Department of Zoology, CAMBRIDGE, CB2 3EJ
Reinterpretation of gizzard sizes of red knots world-wide emphasises overriding importance of prey quality at migratory stopover sites by Dr JA van Gils, Dr PF Battley, Dr T Piersma and Professor R Drent (rspb.2005.3245)
The red knot, a long-distance migrant shorebird, feeds on shellfish, which it ingests whole. It therefore has a relatively large muscular stomach (gizzard), which it uses to crush its hard-shelled prey. Comparing eight sites worldwide, we studied whether the size of the knot's gizzard is adjusted to its energy demand and the quality of its food (the flesh-to-shell ratio). Indeed, the largest gizzards were found in knots feeding on poor quality prey and/or wintering at low ambient temperatures. However, to our surprise, gizzards of knots with extremely high energy demands, i.e. those fuelling for migration, were of intermediate size. Fuelling birds were nevertheless able to rapidly gain body mass because they picked out stopover sites containing super-quality food. This study therefore stresses the critical importance of so-called hotspot stopover sites along the flyway of avian long-distance migrants. This new link between digestive physiology and the vital role of hotspot stopover sites in the lives of migrant shorebirds makes this work newsworthy.
Contact: Dr JA van Gils, Plant-Animal Interactions, Netherlands Institute of Ecology (NIOO-KNAW), Rijksstraatweg 6, NIEUWERSLUIS, 3631 AC, Netherlands
60 million years of co-divergence in the fig-wasp symbiosis by Dr N. Ronsted, Dr G. D. Weiblen, Dr J.M. Cook, Dr N. Salamin, Dr CA Machado and Dr V Savolainen (rspb.2005.3249)
Fig trees are pollinated by wasps that feed exclusively on figs. With over 750 pairs of fig species and pollinating wasp partners, this extraordinary symbiosis is the most extreme example of specialization in a plant- pollinator interaction and has fuelled much speculation about co-evolution. An important question is whether pollinator specialization led to the parallel diversification of fig and pollinating wasp lineages. Using DNA sequence data, we produced the most comprehensive analysis of evolutionary relationships of figs to date and used fossils to generate independent age estimates for fig and pollinator lineages. We show that there are temporal correlations between the origin of at least 10 fig-wasp partnerships; we thereby provide the first and unparalleled example of plant-insect co- divergence for at least the past 60 million years.
Contact: Dr N. Ronsted, Plant Biology, University of Minnesota, 250 Biological Sciences, 1445 Gortner Avenue, SAINT PAUL, 55108, United States
Maintenance of aggressive mimics in a cleaning symbiosis by Dr L Cheney and Dr M. Cote (rspb.2005.3256)
Bluestriped fangblennies bear an uncanny resemblance to cleanerfish, but instead of beneficially removing parasites from fish as cleaners do, mimics tear flesh and scales from unsuspecting victims. The authors discovered that fangblenny mimics were more successful in attacking victims on reefs where they were much rarer than cleanerfish. Rarity probably favours mimics because potential victims encounter attackers less frequently and thus take longer to learn to recognise them. This study provides insights into how parasitic mimicry is maintained in wild populations.
Contact: Dr L Cheney, School of Integrative Biology, University of Queensland, ST. LUCIA, QLD 4072, Australia
Effects of genetically modified herbicide-tolerant cropping systems on weed seedbanks in two years of following crops by Dr LG Firbank, Dr P Rothery, Mr M May, Ms SJ Clark, Mr RJ Scott, Mr RC Stuart, Ms CWH Boffey, Mr. DR Brooks, Dr G Champion, Dr A Haughton, Dr. C. Hawes, Dr MS Heard, Dr AM Dewar, Professor JN Perry and Dr G Squire
The Farm Scale Evaluations (FSEs) have already shown that genetically modified herbicide tolerant (GMHT) crops can affect biodiversity, not because of the way the crops are bred, but rather because of the different herbicides that are used with them. This study considers longer-term effects, by looking at weed seedbanks in the fields used in the FSEs for a following two years of conventional crops. We show that for maize and spring oilseed rape, the effects on seed numbers persist throughout that time. This was not the case for seedbanks following beet crops. The research suggests that there may be long term effects of GMHT crops on biodiversity.
Contact: Dr LG Firbank, NERC Centre for Ecology and Hydrology, Lancaster Environment Centre, Library Avenue, Bailrigg, Lancaster, LA1 4AP
A comparative study of the anti-settlement properties of mytilid shells by Ms AV Bers, Ms GS Prendergast, Ms CM Zurn, Dr LJ Hansson, Dr RM Head and Dr JC Thomason
All immersed hard substrata in the sea face suffer fouling from micro-organisms, algal spores and planktonic larvae of sessile invertebrates. This is harmful to living organisms and marine organisms have evolved defence mechanisms to prevent fouling occurring. This study investigated potential anti-settlement properties of natural microstructures on shells of related two mussel species, Mytilus edulis and Perna perna. We used barnacle larvae as the settlement threat. Our results indicate that shells of both mussel species possess anti-settlement property, that the property is not locally adapted, and is due to the pattern on the shells.
Contact: Ms AV Bers, Benthic Ecology, IFM-Geomar Leibniz Institute of Marine Sciences, Duesternbrooker Weg 20, KIEL, 24105, Germany
Egg-independent release of stored sperm in female Drosophila melanogaster by Professor MC Bloch Qazi and Professor MF Wolfner
Sperm stored in female animals allow prolonged fertility after mating. Sperm must leave storage to fertilize eggs, yet little is known about what controls this exit. You might imagine, for example, that sperm could only leave storage if eggs were available to be fertilized. We used fruit flies to this idea. We found, surprisingly, that sperm exit storage whether or not the female can make eggs. Although eggs influence when sperm-exit begins, they are not necessary for subsequent sperm exit nor for the rate of exit. These interactions illustrate an interplay of male and female factors needed for successful reproduction.
Contact: Professor M Bloch Qazi, Biology, Gustavus Adolphus College, 800 West College Avenue, ST. PETER, MN, 56082, United States
Hummingbirds rely on passive intestinal glucose absorption to fuel high metabolism by Dr. TJ McWhorter, Mr. B Hartman Bakken, Dr. WH Karasov and Dr C Martinez del Rio
Hummingbirds are among the smallest warm-blooded vertebrates, and for their size they require exceptional amounts of energy. Twenty years ago, the highest active glucose absorption rates measured in vertebrates were reported in hummingbirds. McWhorter et al. report new findings demonstrating that passive absorption of glucose is much higher in hummingbirds than previously thought. Even while possessing the highest active glucose absorption rates measured in vertebrates, hummingbirds must rely partially on passive nutrient absorption to meet their high metabolic demands. These findings are an interesting revision to our understanding of how energy absorption occurs in hummingbirds, widely studied as models of energy balance.
Contact: Dr. TJ McWhorter, Wildlife Ecology, University of Wisconsin, 226 Russell Labs, MADISON, WISCONSIN, 53706, United States
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