Search results for "SELE"

Evolution of Complex Acoustic Signals in Drosophila Species

2009

species produce complex acous-tic cues, so-called courtship songs, while pursuing a female.In most of the over 100 species studied so far (see thelist of these species in Hoikkala, 2005), such cues areproduced by wing vibration. Other mechanisms of songproduction include abdomen purring (Hoy, Hoikkala, &Kaneshiro, 1988) and rapid vibrations of the whole body(Ritchie & Gleason, 1995). The carrier frequency of songsproduced through any of these actions ranges from 150 to500Hz. A hitherto unknown mechanism enables males ofsome Hawaiian species to generate songs of up to 15,000Hz(Hoikkala, Hoy, & Kaneshiro, 1989).The structure of the courtship songs of closely relatedspecies often reflects phylo…

Bayesian Hierarchical Models for Random Routes in Finite Populations

1996

In many practical situations involving sampling from finite populations, it is not possible (or it is prohibitely expensive) to access, or to even produce, a listing of all of the units in the population. In these situations, inferences can not be based on random samples from the population. Random routes are widely used procedures to collect data in absence of well defined sampling frames, and they usually have either been improperly analyzed as random samples, or entirely ignored as useless. We present here a Bayesian analysis of random routes that incorporates the information provided but carefully takes into account the non- randomness in the selection of the units.

Herramientas estadísticas para resolver contrastes de hipótesis con contenido biológico: su uso en ecología del siglo XXI

2008

Amenudo la formación que han recibido durante la carrera los jóvenes investigadores tiene notables carencias en los aspectos prácticos de diseño experimental, análisis de datos e interpretación de resultados, lo cual limita de manera decisiva el provecho científico futuro de sus actividades. Eso es especialmente cierto en nuestros días, ya que vivimos una revolución importante en el campo de la metodología estadística e incluso en el procedimiento de hacer inferencia (el salto matemático desde las propiedades de nuestra muestra de datos a las de los parámetros desconocidos de la población, nuestro objeto de estudio), que afecta no sólo a los ecólogos sino a muchas otras disciplinas científi…

Sex-Specific Habitat Selection in an Edge Habitat Specialist, the Western Barbastelle Bat

2011

The niche variation hypothesis suggests that a population's ability to react to varying environmental conditions depend on the behavioural variability of its members. However, most studies on bats, including the work on the habitat use of the western barbastelle bat, Barbastella barbastellus, have not considered sex-specific and individual variability. We studied the habitat use of 12 female and five male western barbastelle bats within their home ranges with respect to available habitat types by applying kernel methods and Euclidean distances. Our results indicate individual habitat preferences within and among sexes of this species. Females preferred deciduous forest and linear elements w…

2014

Captive breeding for conservation purposes presents a serious practical challenge because several conflicting genetic processes (i.e., inbreeding depression, random genetic drift and genetic adaptation to captivity) need to be managed in concert to maximize captive population persistence and reintroduction success probability. Because current genetic management is often only partly successful in achieving these goals, it has been suggested that management insights may be found in sexual selection theory (in particular, female mate choice). We review the theoretical and empirical literature and consider how female mate choice might influence captive breeding in the context of current genetic…

Influences of geographic differentiation in the forewing warning signal of the wood tiger moth in Alaska

2014

Aposematic organisms have warning signals advertising their unpalatability to predators, and because signal efficiency is better in higher densities, positive frequency-dependent selection is expected to select against less common signals. The wood tiger moth (Parasemia plantaginis) occurs across the Holarctic and its conspicuous hindwings serve as warning signals to predators. It also has conspicuous black and white forewing patterns that could act as warning signals, or help to hide the moth by preventing predators from seeing the outline of the moth’s body (a strategy known as disruptive coloration). In Alaska, the predominant forewing pattern changes distinctly between the regions aroun…

Inclusive fitness and sexual conflict: How population structure can modulate the battle of the sexes

2014

Competition over reproductive opportunities among members of one sex often harms the opposite sex, creating a conflict of interest between individual males and females. Recently, this battle of the sexes has become a paradigm in the study of intersexual coevolution. Here, we review recent theoretical and empirical advances suggesting that – as in any scenario of intraspecific competition – selfishness (competitiveness) can be influenced by the genetic relatedness of competitors. When competitors are positively related (e.g. siblings), an individual may refrain from harming its competitor(s) and their mate(s) because this can improve the focal individual's inclusive fitness. These findings r…

Mate‐Search Efficiency Can Determine the Evolution of Separate Sexes and the Stability of Hermaphroditism in Animals

2002

Limited availability of mating partners has been proposed as an explanation for the occurrence of simultaneous hermaphroditism in animals with pair mating. When low population density or low mobility of a species limits the number of potential mates, simultaneous hermaphrodites may have a selective advantage because, first, they are able to adjust the allocation of resources between male and female functions in order to maximize fitness; second, in a hermaphroditic population the likelihood of meeting a partner is higher because all individuals are potential mates; and, third, in the absence of mating partners, many simultaneously hermaphroditic animals have the option of reproducing throug…

Operational sex ratio and resource defence as predictors of the mating system in European bitterling

2003

Operational sex ratio (OSR), the ratio of sexually active males to fertilizable females in a population, plays a central role in the theory of mating systems by predicting that the intensity of male–male competition and the degree of sexual selection increases as the OSR becomes increasingly male biased. At high values of OSR, however, resource defence theory predicts the breakdown of territoriality and a shift towards scramble competition with a decrease in sexual selection. The direction that correlations between OSR and resource competition and variance in mating success will take depends on the biology of the species of interest. We investigated the effects of male population density an…

Can adaptation lead to extinction?

2005

Ever since J.B.S. Haldane proposed the idea, evolutionary biologists are aware that individual level adaptations do not necessarily lead to optimal population performance. A few deeply mathematical models, drawing from a diverse range of systems, even predict that individual selection can lead to the extinction of the whole population, a phenomenon which has become known as evolutionary suicide. Due to the complexity of both following adaptation and determining the exact cause of an extinction, evolutionary suicide has remained untested empirically. However, three recent empirical studies suggest that it may occur, and that suicide should be taken seriously as a potentially important evolut…