Where the rare species are

Prioritizing geographic areas for conservation attention is important – time and money are in short supply but endangered species are not – and difficult. One popular perspective highlights areas with many species found nowhere else ( Myers et al. 2000 ). Another identifies areas that contain species with fewer close relatives elsewhere ( Faith 1992 ). One might characterize the first as focusing on geographic, and the second on phylogenetic, rarity. To the extent that geographically rare species are at greater risk of extinction ( Gaston & Fuller 2009 ), and that phylogenetically rare species contribute disproportionally to overall biodiversity ( Crozier 1997 ), it would seem reasonable to formally integrate the two approaches. In this issue, Rosauer et al. (2009) do just that; their elegant combined metric pinpoints areas missed out when the two types of rarity are looked at in isolation.     

Intergenerational reproductive parasitism in a stingless bee

Insect colonies have been traditionally regarded as closed societies comprised of completely sterile workers ruled over by a single once-mated queen. However, over the past 15 years, microsatellite studies of parentage have revealed that this perception is far from the truth ( Beekman & Oldroyd 2008 ). First, we learned that honey bee queens are far more promiscuous than we had previously imagined ( Estoup et al. 1994 ), with one Apis dorsata queen clocked at over 100 mates ( Wattanachaiyingcharoen et al. 2003 ). Then Oldroyd et al. (1994) reported a honey bee colony from Queensland, where virtually all the males were sons of a single patriline of workers – a clear case of a cheater mutant that promoted intra-colonial reproductive parasitism. Then we learned that both bumble bee colonies ( Lopez-Vaamonde et al. 2004 ) and queenless honey bee colonies ( Nanork et al. 2005, 2007 ) are routinely parasitized by workers from other nests that fly in and lay male-producing eggs that are then reared by the victim colony. There is even evidence that in a thelytokous honey bee population, workers lay female-destined eggs directly into queen cells, thus reincarnating themselves as a queen ( Jordan et al. 2008 ). And let us not forget ants, where microsatellite studies have revealed equally bizarre and totally unexpected phenomena (e.g. Cahan & Keller 2003 ; Pearcy et al. 2004 ; Fournier et al. 2005 ). Now, in this issue, Alves et al. (2009) use microsatellites to provide yet another shocking and completely unexpected revelation about the nefarious goings-on in insect colonies: intergenerational reproductive parasitism by stingless bee workers.     

The biogeography of avian extinctions on oceanic islands revisited

A recent paper by Karels et al ., 'The biogeography of avian extinctions on oceanic islands' ( Journal of Biogeography , 2008, 35 , 1106–1111), uses structural equation modelling to assess the causes of the number of island bird species driven extinct in the historical period. Here, we critically assess the conclusions of the paper and argue that it does not provide the new insights into the causes of extinction in island birds that its authors claim.     

Behavioral characterization of mice lacking the ubiquitin ligase UBR1 of the N-end rule pathway

The N-end rule pathway, a subset of the ubiquitin pathway, relates the in vivo half-life of a protein to the identity of its N-terminal residue. Mice lacking NTAN1, a component of the N-end rule pathway, showed altered learning and memory, and socially conditioned behavioral alteration ( Balogh, Kwon, & Denenberg 1999, 2000 ; Kwon, Balogh et al . 2000 ; Balogh et al . 2001 ). Mice lacking UBR1 (E3α), one of at least three recognition components of the N-end rule pathway, are viable and outwardly normal. Here we describe behavioral characterizations of UBR1 knockout (UBR1^–/–) mice. Compared to congenic littermates, UBR1^–/– mice exhibited less spontaneous activity in an open field and took longer to locate the hidden platform during eight-week Morris water maze retention. In contrast, they performed better in horizontal–vertical discrimination and Lashley III maze testing. No statistically significant differences in inhibitory learning were observed. With the exception of enhanced Lashley III maze performance, these data parallel findings with NTAN1^–/– mice lacking the upstream component of UBR1. These results suggest that, like NTAN1, UBR1 is involved in learning and memory.     

Strong requirements for weak diversities

Weikard et al . ( Diversity and Distributions , 12 , 215–217) show that the taxonomic diversity measure proposed by Ricotta (2004) violates 'weak species monotonicity'. This condition requires that the addition of a species to a given species set should always increase diversity if abundances change only marginally. They further propose a new taxonomic diversity index that overcomes this drawback. In this paper, some statistical properties of this new diversity index are briefly analysed.     

Searching for sex‐reversals to explain population demography and the evolution of sex chromosomes

Sex determination can be purely genetic (as in mammals and birds), purely environmental (as in many reptiles), or genetic but reversible by environmental factors during a sensitive period in life, as in many fish and amphibians ( Wallace et al. 1999 ; Baroiller et al. 2009a ; Stelkens & Wedekind 2010 ). Such environmental sex reversal (ESR) can be induced, for example, by temperature changes or by exposure to hormone‐active substances. ESR has long been recognized as a means to produce more profitable single‐sex cultures in fish farms ( Cnaani & Levavi‐Sivan 2009 ), but we know very little about its prevalence in the wild. Obviously, induced feminization or masculinization may immediately distort population sex ratios, and distorted sex ratios are indeed reported from some amphibian and fish populations ( Olsen et al. 2006 ; Alho et al. 2008 ; Brykov et al. 2008 ). However, sex ratios can also be skewed by, for example, segregation distorters or sex‐specific mortality. Demonstrating ESR in the wild therefore requires the identification of sex‐linked genetic markers (in the absence of heteromorphic sex chromosomes) followed by comparison of genotypes and phenotypes, or experimental crosses with individuals who seem sex reversed, followed by sexing of offspring after rearing under non‐ESR conditions and at low mortality. In this issue, Alho et al. (2010) investigate the role of ESR in the common frog (Rana temporaria) and a population that has a distorted adult sex ratio. They developed new sex‐linked microsatellite markers and tested wild‐caught male and female adults for potential mismatches between phenotype and genotype. They found a significant proportion of phenotypic males with a female genotype. This suggests environmental masculinization, here with a prevalence of 9%. The authors then tested whether XX males naturally reproduce with XX females. They collected egg clutches and found that some had indeed a primary sex ratio of 100% daughters. Other clutches seemed to result from multi‐male fertilizations of which at least one male had the female genotype. These results suggest that sex‐reversed individuals affect the sex ratio in the following generation. But how relevant is ESR if its prevalence is rather low, and what are the implications of successful reproduction of sex‐reversed individuals in the wild?     

Calcareous sponges of the genera Clathrina and Guancha (Calcinea, Calcarea, Porifera) of Norway (north-east Atlantic) with the description of five new species

The taxonomy and distribution of 11 species of calcareous sponges of the subclass Calcinea from the Norwegian coast are reviewed. The Norwegian Calcinea represents a mixture of southern boreal/boreal and boreoarctic species, and the calcinean sponge fauna of northern Norway has strong similarities to the Greenlandic and the White Sea/Barents Sea sponge faunas. Most Norwegian Calcinea have their main distribution between 20 and 100 m depth, although some species are found only in the shallow sublittoral or from sublittoral to abyssal depths. Six species were previously reported in the area: Clathrina coriacea (Montagu, 1818), Clathrina cribrata Rapp et al ., 2001, Clathrina nanseni (Breitfuss, 1896), Clathrina septentrionalis Rapp et al ., 2001, Guancha blanca Miklucho-Maclay, 1868 and Guancha lacunosa (Johnston, 1842). Five species are new to science: Clathrina corallicola , Clathrina jorunnae , Guancha arnesenae , Guancha camura , and Guancha pellucida spp. nov. A key to the known Norwegian Calcinea is provided.  © 2006 The Linnean Society of London, Zoological Journal of the Linnean Society , 2006, 147 , 331–365.     

Increasing longevity through caloric restriction or rapamycin feeding in mammals: common mechanisms for common outcomes?

Significant extension of lifespan in important mammalian species is bound to attract the attention not only of the aging research community, but also the media and the wider public. Two recent papers published by Harrison et al. (2009) in Nature and by Colman et al. (2009) in Science report increased longevity of mice fed with rapamycin and of rhesus monkeys undergoing caloric restriction, respectively. These papers have generated considerable debate in the aging community. Here we assess what is new about these findings, how they fit with our knowledge of lifespan extension from other studies and what prospects this new work holds out for improvements in human longevity and human health span.     

The population ecology of house mice (Mus domesticus) on the Isle of May, Scotland

The colonizing ability, catholic habitat utilization and wide distribution of house mice ( Mus domesticus , Rutty) are indicators of their ecological resilience. Numerous studies have been made of commensal, caged and free-living mouse populations though few have assessed the relative importance of physiological and genetical components of adaptability in a simple ecosystem. This paper reports such findings, derived from live-trapping which formed part of an inter-disciplinary study of adaptability in a feral population of house mice living on a small Scottish island (57 ha).
The population size ranged from450–3250 animals. A high proportion of mice showed homerange tenacity, though15–20% shifted their range during winter. This 'churning' of the population is consistent with the island population forming an effectively panmictic unit rather than fragmented demes. The breeding season, survival of individuals and change in population size related to patterns of gross climatic variation (temperature and rainfall) so that rates of reproduction and survival were lowest in cold, wet conditions. Thermoregulatory adjustment of the mice to lowered ambient temperatures and its contribution to overwinter survival are discussed. Genetical monomorphism of May Island mice is discussed in relation to their biological performance compared with other populations, especially that of the ecologically comparable Skokholm Island (Wales).     

Management implications of the Macquarie Island trophic cascade revisited: a reply to Dowding et al. (2009)

1. The management of non-indigenous species is not without its complications. In Bergstrom et al. 's (2009) study, we demonstrated that feral cats Felis catus on sub-Antarctic Macquarie Island were exerting top-down control on the feral rabbit Oryctolagus cuniculus population, and that the eradication of the cats led to a substantial increase in rabbit numbers and an associated trophic cascade.
2. Dowding et al. (2009) claim our modelling was flawed for various reasons, but primarily that a reduction in the application of the rabbit control agent, Myxoma virus, coinciding with cat removal, was a major driver of rabbit population release.
3. We explore this proposition (as well as others) by examining rates of Myxoma viral release between 1991 and 2006 (with an attenuation factor for the years, 2003–2006) in association with presence/absence of cats against two estimates of rabbit population size. Myxoma viral release was a significant factor in the lower estimates of rabbit population, but the effect was small, and was not significant for higher rabbit population estimates. By contrast, the presence or absence of cats remained highly significant for both estimates.
4. Synthesis and applications. We re-affirm our position that top-down control of rabbit numbers by cats, prior to their eradication, was occurring on Macquarie Island. Nonetheless, we agree with Dowding et al. (2009) that systems with multiple invasive species represent complex situations that require careful scrutiny. Such scrutiny should occur in advance of, during, and following management interventions.     

Immune correlates of protection against anthrax

Bacillus anthracis protective antigen (PA) has been produced from a recombinant B. subtilis and its efficacy, when combined with the Ribi adjuvant (MPL-TDW-CWS) or alhydrogel, has been compared with that of the licensed UK human vaccine, in guinea pigs challenged with aerosolized Ames strain spores. Recombinant PA combined with the Ribi adjuvant performed as well as PA from B. anthracis cultures in previous reports ( Ivins & Welkos 1986 ; Ivins et al . 1990 ; Turnbull et al . 1991 ; Jones et al . 1996 ; McBride et al . 1998 ) giving protection in 100% of animals exposed to the highest challenge dose of the Ames strain of B. anthracis that can be administered practically (retained lung doses of approximately 10⁶ spores).
In attempts at identifying markers of protection in immunized individuals, rPA in combination with the Ribi adjuvant induced a marker IgG₂ response in guinea pigs with no significant differences in IgG₁ levels when compared with other vaccine formulations ( McBride et al . 1998 ). In BALBc mice, rPA with the Ribi adjuvant induced a higher IgG_2a response compared with rPA with anhydrogel and the human vaccine.
To examine the role of anti-PA-specific antibodies in protection, guinea pig sera is being passively transferred into guinea pigs and SCID mice, followed by protection.
Similarly, B- and T-lymphocytes from immunized BALB/c mice are being separately and passively transferred into SCID mice with subsequent challenge. The neutralizing ability of the PA-specific antibodies is being studied using an in vitro macrophage lysis assay.     

A closer look at the spatial architecture of aphid clones

Nearly 25 years ago, Ellstrand & Roose (1987) reviewed what was known at the time of the genetic structure of clonal plant species. What is the relationship between space and clonal fitness, they asked. What is the best way for a clone to grow within its ecological neighbourhood? The pot had been stirred 10 years previously by Janzen (1977) , who pointed out how little we know about the population biology of clonal organisms like dandelions and aphids. He wondered whether, like good curries, outward appearances masked common ingredients. Because in no small part of the advent of molecular ecology, we know more about clonal life histories today, particularly in plants ( van Dijk 2003 ; Vallejo‐Marín et al. 2010 ). Surprisingly, studies of the spatial architecture of aphid clones have been comparably rare. In this issue of Molecular Ecology, Vantaux et al. characterize the fine‐scale distribution of the black bean aphid (Aphis fabae) and in so doing, help to fill that gap. They describe a moderate degree of intermingling between aphid clones over a growing season—A. fabae clones are ‘sticky’, but only a bit. By mixing, clones directly compete with each other as well. The results of Vantaux et al. (2011) will help to integrate evolutionary patterns in aphids with the appropriate ecological scales out of which those patterns emerge.     

Ecdysozoa versus Articulata: clades, artifacts, prejudices

The claim that monophyly of the Ecdysozoa is caused by chance similarities in 18S rDNA sequences ( Wägele et al., J. Zool. Syst. Evol. Res. 37, 211–223, 1999 ) is re-analysed from the cladistic point of view. It is shown that the molecular characters supporting the Ecdysozoa do not behave as 'noisy' in empirical studies that use the sensitivity analysis and character congruence approaches. The 'anti-noise' methodology proposed by Wägele et al. (1999) is unable to identify true misinformative data. The monophyly of the Articulata (= Annelida + Panarthropoda), proposed by Wägele et al. (1999) , is contradicted by all molecular data that support either Ecdysozoa (including Panarthropoda), or Lophotrochozoa (including Annelida), or usually both.     

Cell kinetic status of haematopoietic stem cells

The haematopoietic stem cell (HSC) population supports a tremendous cellular production over the course of an animal's lifetime, e.g. adult humans produce their body weight in red cells, white cells and platelets every 7 years, while the mouse produces about 60% of its body weight in the course of a 2 year lifespan. Understanding how the HSC population carries this out is of interest and importance, and a first step in that understanding involves the characterization of HSC kinetics. Using previously published continuous labelling data (of Bradford et al. 1997 and Cheshier et al. 1999 ) from mouse HSC and a standard G₀ model for the cell cycle, the steady state parameters characterizing these HSC populations are derived. It is calculated that in the mouse the differentiation rate ranges between about 0.01 and 0.02, the rate of cell re-entry from G₀ back into the proliferative phase is between 0.02 and 0.05, the rate of apoptosis from the proliferative phase is between 0.07 and 0.23 (all units are days⁻¹), and the duration of the proliferative phase is between 1.4 and 4.3 days. These values are compared with previously obtained values derived from the modelling by Abkowitz and colleagues of long-term haematopoietic reconstitution in the cat ( Abkowitz et al. 1996 ) and the mouse ( Abkowitz et al. 2000 ). It is further calculated using the estimates derived in this paper and other data on mice that between the HSC and the circulating blood cells there are between 17 and 19.5 effective cell divisions giving a net amplification of between ~170 000 and ~720 000.     

How old are you now?

Cherkas et al . provide a new, biological approach to a classic problem in anthropology – the estimation of age.     

Population genomics as a new tool for wildlife management

Admixture and introgression have varied effects on population viability and fitness. Admixture might be an important source of new alleles, particularly for small, geographically isolated populations. However, admixture might also cause outbreeding depression if populations are adapted to different ecological or climatic conditions. Because of the emerging use of translocation and admixture as a conservation and wildlife management strategy to reduce genetic load (termed genetic rescue), the possible effects of admixture have practical consequences ( Bouzat et al. 2009 ; Hedrick & Fredrickson 2010 ). Importantly, genetic load and local adaptation are properties of individual loci and epistatic interactions among loci rather than properties of genomes. Likewise, the outcome and consequences of genetic rescue depend on the fitness effects of individual introduced alleles. In this issue of Molecular Ecology, Miller et al. (2012) use model‐based, population genomic analyses to document locus‐specific effects of a recent genetic rescue in the bighorn sheep population within the National Bison Range wildlife refuge (NBR; Montana, USA). They find a subset of introduced alleles associated with increased fitness in NBR bighorn sheep, some of which experienced accelerated introgression following their introduction. These loci mark regions of the genome that could constitute the genetic basis of the successful NBR bighorn sheep genetic rescue. Although population genomic analyses are frequently used to study local adaptation and selection (e.g. Hohenlohe et al. 2010 ; Lawniczak et al. 2010 ), this study constitutes a novel application of this analytical framework for wildlife management. Moreover, the detailed demographic data available for the NBR bighorn sheep population provide a rare and powerful source of information and allow more robust population genomic inference than is often possible.     

On the International Code of Area Nomenclature (ICAN): a reply to Zaragüeta-Bagils et al.

In 2007 the Systematic and Evolutionary Biogeographical Association (SEBA) wrote and ratified the first draft of the International Code of Area Nomenclature (ICAN), which was posted subsequently on the SEBA website. The ICAN was published, along with an explanatory discussion, by Ebach et al. ( Journal of Biogeography , 35 , 2008, 1153–1157), an article that is the subject of criticism by Zaragüeta-Bagils et al. ( Journal of Biogeography , 36 , 2009, 1617–1618). We welcome discussion of the issues raised by these authors and respond to them briefly here. For many reasons, we reject the proposition that implementation of the ICAN be postponed until it is flawless. The ICAN has already been implemented. Further, it is the nature of nomenclatural codes to be proposed and then revised periodically to suit our applications. Most importantly, standardization of area names in biogeography is long overdue.     

Speciation genetics of biological invasions with hybridization

The negative effects of human‐induced habitat disturbance and modification on multiple dimensions of biological diversity are well chronicled ( Turner 1996 ; Harding et al. 1998 ; Lawton et al. 1998 ; Sakai et al. 2001 ). Among the more insidious consequences is secondary contact between formerly allopatric taxa ( Anderson & Hubricht 1938 ; Perry et al. 2002 ; Seehausen 2006 ). How the secondary contact will play out is unpredictable ( Ellstrand et al. 2010 ), but if the taxa are not fully reproductively isolated, hybridization is likely, and if the resulting progeny are fertile, the eventual outcome is often devastating from a conservation perspective ( Rhymer & Simberloff 1996 ; Wolf et al. 2001 ; McDonald et al. 2008 ). In this issue of Molecular Ecology, Steeves et al. (2010) present an analysis of hybridization between two avian species, one of which is critically endangered and the other of which is invasive. Their discovery that the endangered species has not yet been hybridized to extinction is promising and not what one would necessarily expect from theory.