Recent range-wide demographic expansion in a Taiwan endemic montane bird, Steere's Liocichla (Liocichla steerii)

<p>Abstract</p> <p>Background</p> <p>The subtropical island of Taiwan is an area of high endemism and a complex topographic environment. Phylogeographic studies indicate that vicariance caused by Taiwan's mountains has subdivided many taxa into genetic phylogroups. We used mitochondrial DNA sequences and nuclear microsatellites to test whether the evolutionary history of an endemic montane bird, Steere's Liocichla (<it>Liocichla steerii</it>), fit the general vicariant paradigm for a montane organism.</p> <p>Results</p> <p>We found that while mountains appear to channel gene flow they are not a significant barrier for Steere's Liocichla. Recent demographic expansion was evident, and genetic diversity was relatively high across the island, suggesting expansion from multiple areas rather than a few isolated refugia. Ecological niche modeling corroborated the molecular results and suggested that populations of Steere's Liocichla are connected by climatically suitable habitat and that there was less suitable habitat during the Last Glacial Maximum.</p> <p>Conclusions</p> <p>Genetic and ecological niche modeling data corroborate a single history--Steere's Liocichla was at lower density during the Last Glacial Maximum and has subsequently expanded in population density. We suggest that such a range-wide density expansion might be an overlooked cause for the genetic patterns of demographic expansion that are regularly reported. We find significant differences among some populations in <it>F</it>_{<it>ST </it>}indices and an admixture analysis. Though both of these results are often used to suggest conservation action, we affirm that statistically significant results are not necessarily biologically meaningful and we urge caution when interpreting highly polymorphic data such as microsatellites.</p

Genomic Analysis of Demographic History and Ecological Niche Modeling in the Endangered Sumatran Rhinoceros Dicerorhinus sumatrensis

The vertebrate extinction rate over the past century is approximately 22–100 times greater than background extinction rates [1], and large mammals are particularly at risk [2, 3]. Quaternary megafaunal extinctions have been attributed to climate change [4], overexploitation [5], or a combination of the two [6]. Rhinoceroses (Family: Rhinocerotidae) have a rich fossil history replete with iconic examples of climate-induced extinctions [7], but current pressures threaten to eliminate this group entirely. The Sumatran rhinoceros(Dicerorhinus sumatrensis) is among the most imperiled mammals on earth. The 2011 population was estimated at ≤216 wild individuals [8], and currently the species is extirpated, or nearly so, throughout the majority of its former range [8–12]. Understanding demographic history is important in placing current population status into a broader ecological and evolutionary context. Analysis of the Sumatran rhinoceros genome reveals extreme changes in effective population size throughout the Pleistocene. Population expansion during the early to middle Pleistocene was followed by decline. Ecological niche modeling indicated that changing climate most likely played a role in the decline of the Sumatran rhinoceros, as less suitable habitat on an emergent Sundaland corridor isolated Sumatran rhinoceros populations. By the end of the Pleistocene, the Sundaland corridor was submerged, and populations were fragmented and consequently reduced to low Holocene levels from which they would never recover. Past events denuded the Sumatran rhinoceros of genetic diversity through population decline, fragmentation, or some combination of the two and most likely made the species even more susceptible to later exploitation and habitat loss

An introduction to genetic quality in the context of sexual selection

This special issue of Genetica brings together empirical researchers and theoreticians to present the latest on the evolutionary ecology of genetic quality in the context of sexual selection. The work comes from different fields of study including behavioral ecology, quantitative genetics and molecular genetics on a diversity of organisms using different approaches from comparative studies, mathematical modeling, field studies and laboratory experiments. The papers presented in this special issue primarily focus on genetic quality in relation to ( 1) sources of genetic variation, ( 2) polyandry, ( 3) new theoretical developments and ( 4) comprehensive reviews

Demographic, Psychological, and Social Characteristics of Self-Identified Lesbian, Gay, and Bisexual Adults in a US Probability Sample

Using data from a US national probability sample of self-identified lesbian, gay, and bisexual adults (N = 662), this article reports population parameter estimates for a variety of demographic, psychological, and social variables. Special emphasis is given to information with relevance to public policy and law. Compared with the US adult population, respondents were younger, more highly educated, and less likely to be non-Hispanic White, but differences were observed between gender and sexual orientation groups on all of these variables. Overall, respondents tended to be politically liberal, not highly religious, and supportive of marriage equality for same-sex couples. Women were more likely than men to be in a committed relationship. Virtually all coupled gay men and lesbians had a same-sex partner, whereas the vast majority of coupled bisexuals were in a heterosexual relationship. Compared with bisexuals, gay men and lesbians reported stronger commitment to a sexual-minority identity, greater community identification and involvement, and more extensive disclosure of their sexual orientation to others. Most respondents reported experiencing little or no choice about their sexual orientation. The importance of distinguishing among lesbians, gay men, bisexual women, and bisexual men in behavioral and social research is discussed

Sexual Dimorphism and Dichromatism in Steere\u27s Liocichla (Liocichla steerii)

Although sexual differences in birds can be extreme, differences between males and females in body size and plumage color are more subtle in many species. We used a genetic-based approach to determine the sex of male and female Steere\u27s Liocichla (Liocichla steerii) and examine the degree of size dimorphism and plumage dichromatism in this apparently monomorphic species. We found that males were significantly larger than females. In addition, Steere\u27s Liocichla have a prominent yellow plumage patch on the lores that was significantly larger in males than females for both live birds and museum specimens. We also used reflectance spectrometry to quantify the color of the yellow-green breast feathers of Steere\u27s Liocichla and found no significant differences between males and females in brightness, intensity, saturation, or hue. However, females tended to have brighter breast plumage, particularly at long wavelengths. Collectively, these color variables were useful in discriminating birds according to sex when used in a discriminant function analysis. Our study suggests that sexual selection may be more widespread than once assumed, even among birds considered monomorphic, and emphasizes the need for additional data from tropical and subtropical species. /// Aunque las diferencias sexuales entre algunas especies puede ser estrechas, un muchas de estas las diferencias corporales entre los sexos pudiera ser sutiles. Abordamos el asunto basados en genética para determinar el sexo en Liocichla steerii y examinamos el grado de dimorfismo sexual y dicromatismo en el plumaje en esta especie la cual aparentemente es monomórfica. Encontramos que los machos eran significativamente de mayor tamaño que las hembras. Además encontramos en los machos un parcho amarillo en los lores significativamente más grande que en las hembras, tanto en aves del estado silvestre como en pieles de museos. Usamos espectrometría para cuantificar el color de las plumas verde-amarillentas del pecho de las aves y no encontramos diferencias significativas entre los sexos, con respecto a la brillantez, insensidad, saturación o matiz color. Sin embargo, las hembras tuvieron la tendencia a tener el plumaje más brillante en el pecho particularmente en el espectro de onda larga. Colectivamente, estas variables de color fueron útiles para discriminar entre el sexo de las aves, particularmente cuando fueron examinadas utilizando un análisis discriminante de funciones. Nuestro estudio sugiere que la selección sexual pudiera estar más ampliamente distribuida que lo previamente asumido, aún en aves consideradas monomórficas. Además el trabajo enfatiza la necesidad de llevar a cabo estudios adicionales, de este tipo, tanto en especies del trópico como de la zona templada

Data from: Genomic analysis of demographic history and ecological niche modeling in the endangered Sumatran Rhinoceros Dicerorhinus sumatrensis

The vertebrate extinction rate over the past century is approximately 22–100 times greater than background extinction rates, and large mammals are particularly at risk. Quaternary megafaunal extinctions have been attributed to climate change, overexploitation, or a combination of the two. Rhinoceroses (Family: Rhinocerotidae) have a rich fossil history replete with iconic examples of climate-induced extinctions, but current pressures threaten to eliminate this group entirely. The Sumatran rhinoceros (Dicerorhinus sumatrensis) is among the most imperiled mammals on earth. The 2011 population was estimated at ≤216 wild individuals, and currently the species is extirpated, or nearly so, throughout the majority of its former range. Understanding demographic history is important in placing current population status into a broader ecological and evolutionary context. Analysis of the Sumatran rhinoceros genome reveals extreme changes in effective population size throughout the Pleistocene. Population expansion during the early to middle Pleistocene was followed by decline. Ecological niche modeling indicated that changing climate most likely played a role in the decline of the Sumatran rhinoceros, as less suitable habitat on an emergent Sundaland corridor isolated Sumatran rhinoceros populations. By the end of the Pleistocene, the Sundaland corridor was submerged, and populations were fragmented and consequently reduced to low Holocene levels from which they would never recover. Past events denuded the Sumatran rhinoceros of genetic diversity through population decline, fragmentation, or some combination of the two and most likely made the species even more susceptible to later exploitation and habitat loss

A molecular phylogenetic hypothesis for the manakins (Aves: Pipridae)

Phylogenetic relationships among the 14 manakin genera were inferred from DNA sequence data obtained from both mitochondrial and nuclear DNA loci. Phylogenetic analysis resulted in a well-supported hypothesis that corroborates a sister relationship between tyrant-manakins and the “core” manakins (Antilophia, Chiroxiphia, Corapipo, Dixiphia, Heterocercus, Ilicura, Lepidothrix, Manacus, Masius, Machaeropterus, Pipra, and Xenopipo). Our data strongly support these core manakin genera as a monophyletic group. Consistent with previous work, we find two major clades within the core manakins, although the placement of the genus Xenopipo with regards to these two clades is ambiguous. Generic relationships within these clades are generally well resolved. Although we find some concordance between our study and a previous manakin phylogeny based on syringeal characters, we note several fundamental differences between the phylogenies. Thus, we offer a new phylogenetic hypothesis for Pipridae