A magnificent atmosphere? Romanian immigration in the political debate of Madrid,Spain

Immigration has consistently been one of the most controversial political topics in many European countries over recent years. Much research has consequently focused on highlighting and describing negative views of immigrants which dominate political debate. This has been particularly the case in studies of Spain. Yet such studies rarely examine positive views of immigration or explain the dominance of some views over others. This article offers a distinct contribution by examining the contested framing of Romanian immigration in Madrid's politics. At the same time that Romanian immigration has increased rapidly to form the largest single nationality population in the country and public opinion has registered specific concerns regarding this nationality, political debate has declared a ‘magnificent atmosphere’ of coexistence. The article explores why, highlighting the stability of discursive and institutional structures which emphasise values of democracy, equality and tolerance over potentially discriminatory acts and statements.     

Natural selection in populations subject to a migration load

Migration tends to oppose the effects of divergent natural selection among populations. Numerous theoretical and empirical studies have demonstrated that this migration-selection balance constrains genetic divergence among populations. In contrast, relatively few studies have examined immigration's effects on fitness and natural selection within recipient populations. By constraining local adaptation, migration can lead to reduced fitness, known as a "migration load," which in turn causes persistent natural selection. We develop a simple two-island model of migration-selection balance that, although very general, also reflects the natural history of Timema cristinae walking-stick insects that inhabit two host plant species that favor different cryptic color patterns. We derive theoretical predictions about how migration rates affect the level of maladaptation within populations (measured as the frequency of less-cryptic color-pattern morphs), which in turn determines the selection differential (the within-generation morph frequency change). Using data on color morph frequencies from 25 natural populations, we confirm previous results showing that maladaptation is higher in populations receiving more immigrants. We then present novel evidence that this increased maladaptation leads to larger selection differentials, consistent with our model. Our results provide comparative evidence that immigration elevates the variance in fitness, which in turn leads to larger selection differentials, consistent with Fisher's Theorem of Natural Selection. However, we also find evidence that recurrent adult migration between parapatric populations may tend to obscure the effects of selection.     

Demographic and genetic description of Greenland's only indigenous Atlantic salmon Salmo salar population

A survey of the Kapisillit River system was conducted in 2005 and 2012 to study the only indigenous Atlantic salmon Salmo salar population in Greenland. Little is known about its characteristics or its relationship with other S. salar populations across the species range. Juvenile S. salar were captured in all stations surveyed within the lower river with the highest densities lower in the river and decreasing densities with increasing distance from the river mouth. Captured juveniles ranged from 0+ to 7+ years old and the predominant smolt age was between 4 and 6 years. Median length of 0+ and 1+ juveniles in August–September was 38.8 and 70.4 mm, respectively. The proportion of mature male parr increased from 4% for 1+ year old fish to 95% for fish greater than 2 years old. Genetic analysis using 96 single nucleotide polymorphisms (SNP) revealed a high degree of genetic similarity between collections, extremely low genetic diversity and low estimates of effective population size (N_e = 28.7; 95% CI = 19.7–42.4). Genetic comparison to range-wide S. salar populations demonstrated that the Kapisillit River S. salar is an outgroup of the eastern Atlantic stock complex, which is consistent with the hypothesised colonisation from the east. River morphology and the absence of glacier runoff are hypothesised to be the main reasons for the relatively high river temperatures supporting this self-sustaining population of S. salar. Given its uniqueness and persistence, this population represents an important part of range-wide biodiversity of S. salar.     

Selection for litter size in pigs. II. Efficiency of closed and open selection lines*

A selection experiment on litter size in the pig was carried on for seventeen generations in an Inra experimental herd. The founder population was made up of 10 males and 120 females from the Large White breed. Selection was first performed for ten generations in a closed line, compared to a control line derived from the same founder population. Selection was carried on within sire family on the total number of piglets born in the first two litters of the dam (TB1 + TB2). After ten generations, the selection criterion became dam TB1 only. The control line was then discontinued and a panel of frozen semen from the 11th generation boars was created for later comparisons. The selected line was opened to gilt daughters of hyperprolific boars and sows, at a rate of 1/8 per generation, and the same selection procedure was applied irrespective of the origin of the gilt. During the whole experiment, the number of ova shed (OS) and the number of live embryos (LE) at 30 days in the 3rd pregnancy were recorded. These two parts of the experiment were analysed using REML estimation of genetic parameters and a BLUP-Animal Model in order to estimate the responses to selection. Significant heritabilities for TB1, TB2, OS and LE were obtained, i.e. 0.10, 0.05, 0.43 and 0.19, respectively. Significant common environment variances and covariances were estimated for nearly all traits. Significantly positive BLUP responses per generation were observed from G0 to G17 for TB1 (+0.086), TB2 (+0.078), OS (+0.197) and LE (+0.157). However, the responses were 3- to 4-fold higher in the G12–G17 interval compared to G0–G11, and they were also in fair agreement with previous estimates based on standard least-squares procedures, using the control line and the control frozen semen panel. Since G11, the selection intensity was increased by nearly 80 p. cent compared to the previous generations, and the proportion of hyperprolific ancestry increased up to 65 p. cent in the sows of the last generation. The total genetic gain of about 1.4 piglets at birth per litter could be shared between a gain due to immigration, of about 0.8 piglets per litter, and a within-line selection gain of about 0.6 piglets. Thus by combining selection and immigration in the second part of the experiment, advantage could be taken from both the genetic superiority of the immigrants and the higher internal selection intensity made possible by immigration.     

U.S. racial and ethnic relations in the twenty-first century: are old divisions prevailing?

In this response to Valdez and Golash-Boza’s article, U.S. Racial and Ethnic Relations in the twenty-first century, I commend the authors for raising critical issues about the traditional lack of integration of race and ethnicity paradigms. However, I argue that, in an effort to make their claim about the distinction between the ethnicity and race paradigms, they end up oversimplifying some of the literature and overlook the ways in which race and ethnicity scholarship from the twenty-first century has made important advances towards paradigm integration. In my response I provide an alternate reading of some of the literature that the authors critique, focusing on the Mexican middle-class case. I then highlight scholars who are working towards race–ethnicity integration, moving past old paradigm divides. I conclude my response by introducing the concept of the “ethnoracial core”, which I believe moves us in the direction that Valdez and Golash-Boza are proposing.     

Elevational diversity gradients, biogeography and the structure of montane mammal communities in the intermountain region of North America

1  Distribution data were assembled for non-volant small mammals along elevational gradients on mountain ranges in the western U.S.A. Elevational distributions in the species-rich Uinta Mountains were compared to those on smaller mountain ranges with varying degrees of historical isolation from the Uintas.
2  For mountain ranges supporting the richest faunas, species richness is highest over a broad low- to mid-elevation zone and declines at both lower and higher elevations. Patterns on other mountain ranges are similar but reflect lower overall species richness.
3  A basic relationship between elevational and geographical distribution is apparent in the occurrence patterns of mammals on regional mountains. Faunas on mountains that have had low levels of historical isolation appear to be influenced by immigration rather than extinction. Species restricted to high elevations in the Uintas are poorly represented on historically isolated mountains and form a portion of local faunas shaped by extinction. Species occurring at lower elevations in the Uintas have better representation on isolated mountains and apparently maintain populations through immigration.
4  Several widespread species show substantial variation in maximum elevation records on different mountain ranges. This involves (1) an upward shift in habitat zones on small, isolated mountain ranges, allowing greater access by low-elevation species, and (2) expansion of certain low- and mid-elevation species into habitats normally occupied by absent high-elevation taxa.
5  Results indicate that montane mammal faunas of the intermountain region have been shaped by broad-scale historical processes, unique regional geography and local ecological dynamics. Parallel examples among mammals of the Philippine Islands suggest that such patterns may characterize many insular faunas.     

Tracing the history and ecological context of Wolbachia double infection in a specialist host (Urophora cardui)—parasitoid (Eurytoma serratulae) system

The endosymbiotic bacterium Wolbachia is the most widespread bacteria in insects, yet the ecology of novel acquisitions in natural host populations is poorly understood. Using temporal data separated by 12 years, I tested the hypothesis that immigration of a parasitoid wasp led to transmission of its Wolbachia strain to its dipteran host, resulting in double‐strain infection, and I used geographic and community surveys to explore the history of transmission in fly and parasitoid. Double infection in the fly host was present before immigration of the parasitoid. Equal prevalence of double infection in males and females, constant prevalence before and after immigration in two regions, and increase in one region of immigration indicate little if no competition between strains. Double infection was present throughout the fly's distribution range, but proportions varied highly (0–0.71, mean = 0.26). Two fly‐specific MLST strains, observed in Eastern and Western Europe, respectively, differed at hcpA only. Flies with either fly‐strain could be double infected with the parasitoid's strain. The geographic distribution of double infection implies that it is older than the fly host's extent distribution range and that different proportions of double infection are caused by demographic fluctuations in the fly. The geographic data in combination with community surveys of infections and strains further suggest that the parasitoid strain was the fly's ancestral strain that was transmitted to the parasitoid, that is, the reverse transmission route as first hypothesized. Based on these findings together with a comparison of oviposition strategies of other hosts harboring related Wolbachia strains, I hypothesize that trans‐infection during an insect host's puparial metamorphosis might be important in promoting horizontal transmission among diverse holometabolic taxa.     

POPULATION ANALYSES OF INDO-PACIFIC HUMPBACK DOLPHINS SOUSA CHINENSIS IN ALGOA BAY,EASTERN CAPE,SOUTH AFRICA1

Mark-recapture analyses were performed on photo-identification data for Indo-Pacific humpback dolphins (Sousa chinensis) inhabiting Algoa Bay, on the Eastern Cape coast of South Africa. Boat-based photo-ID surveys were undertaken between May 1991 and May 1994. The rate of discovery of newly identified dolphins, distribution of sightings and frequency of resightings of known individuals indicate a high level of seasonal immigration of humpback dolphins into, and emigration from, the Algoa Bay region in summer. Consequently, humpback dolphins from Algoa Bay appear to be part of a substantially larger population that uses a considerable length of the coastal zone. The minimum population size is estimated to be about 466 dolphins.     

Immigration in wild groups of golden lion tamarins (Leontopithecus rosalia)

Seventeen territorial groups of wild golden lion tamarins were monitored for periods of 10–76 months. Immigration into established groups was rare (0.48 immigrating individuals per group per year) and occurred mostly in the context of replacement of breeding individuals. Nonreplacement immigration events usually occurred in conjunction with some other change in group composition (e.g., an emigration or another immigration). Aggression by resident tamarins toward potential immigrants appeared to be the proximate factor limiting movement into groups. Most such aggression was intrasexual, but potential female immigrants were sometimes chased by male as well as female residents. Immigration was highly male biased (85% of individuals). Factors possibly contributing to this bias were inheritance of breeding positions by adult daughters (reducing female and increasing male immigration opportunities), ability of males but not females to join groups already containing a same-sex breeding individual, and the fact that potential female immigrants appeared to face some intersexual as well as intrasexual aggression. Male and female roles in the maintenance of a monogynous mating system are considered in light of these results. Contrasts with data from intruder studies on captive golden lion tamarins [French & Inglett, Animal Behaviour 37:487–497, 1989] are discussed. © 1996 Wiley-Liss, Inc.