A hallmark of eusociality in ants is the reproductive division of labor between queens and workers. Yet, nothing is known about the molecular mechanisms underlying reproduction in this group. We therefore compared the developmental genetic capacity of queens and workers to reproduce in several eusocially advanced species from the two largest subfamilies of ants, the Myrmicinae and Formicinae. I...

The rate of adaptation to a competitive laboratory environment and the associated inbreeding depression in measures of reproductive fitness have been observed in populations of Drosophila melanogaster with mean effective breeding size of the order of 50 individuals. Two large wild-derived populations and a long-established laboratory cage population were used as base stocks, from which subpopul...

Sex differences in spatial learning have been thought to be universal among mammals, but their adaptive significance has been neglected. Spatial-learning skills are hypothesized to evolve in proportion to nagivational demands, and it is predicted that sex differences in spatial ability will evolve only in species where range expansion contributes differentially to the reproductive success of ma...

In anurans reproductive behavior is strongly seasonal. During the spring, frogs emerge from hibernation and males vocalize for mating or advertising territories. Female frogs have the ability to evaluate the quality of the males' resources on the basis of these vocalizations. Although studies revealed that central single torus semicircularis neurons in frogs exhibit season plasticity, the plast...

The evolution of language implies the parallel evolution of an ability to respond appropriately to signals (language understanding) and an ability to produce the appropriate signals in the appropriate circumstances (language production). When linguistic signals are produced to inform other individuals, individuals that respond appropriately to these signals may increase their reproductive chanc...

The evolution of language implies the co-evolution of an ability to respond appropriately to signals (language understanding) and the ability to produce the appropriate signals in the appropriate circumstances (language production). When linguistic signals are produced to inform other individuals, individuals that respond appropriately to signals may increase their reproductive chances but it i...

Musca domestica L. (Diptera: Muscidae) is a relevant domestic, medical and veterinary pest against which new active ingredients must be continuously developed and tested. A key feature of these ingredients is the ability to interfere with the reproductive capacity, causing sterility in both sexes. The authors have developed two simple low-cost devices to evaluate the reproductive capacity in bo...

After spermatogenesis, testicular spermatozoa are not able to fertilize an oocyte, they must undergo sequential maturational processes. Part of these essential processes occurs during the transit of the spermatozoa through the male reproductive tract. Since the sperm become silent in terms of translation and transcription at the testicular level, all the maturational changes that take place on ...

Environmental stressors impact physiology and behavior in many species of animals. These effects are partly mediated through changing concentrations of glucocorticoids, which also vary with reproductive state and social conditions. Prior research has focused largely on seasonal breeders, but the close temporal linkage between season and reproductive state in these species hinders ability to dis...