Oxytocin influences parental care in male threespine stickleback across multiple time scales.

Oxytocin (OXT) and its homologs are known to regulate parental care in vertebrates, but it is unknown what role these neuropeptides may play in the evolutionary loss of care. Here, we compared two recently diverged ecotypes of threespine stickleback (Gasterosteus aculeatus) that differ in parental care. Males of the common ecotype provide obligate, uniparental care to their offspring, whereas males of the white ecotype abandon their offspring after fertilization.

Divergence in Reproductive Behaviors Is Associated with the Evolutionary Loss of Parental Care.

AbstractThe mechanisms underlying the divergence of reproductive strategies between closely related species are still poorly understood. Additionally, it is unclear which selective factors drive the evolution of reproductive behavioral variation and how these traits coevolve, particularly during early divergence. To address these questions, we quantified behavioral differences in a recently diverged pair of Nova Scotian three-spined stickleback () populations, which vary in parental care, with one population displaying paternal care and the other lacking this.

Locomotor effects of a fibrosis-based immune response in stickleback fish.

The vertebrate immune system provides an impressively effective defense against parasites and pathogens. However, these benefits must be balanced against a range of costly side-effects including energy loss and risks of auto-immunity. These costs might include biomechanical impairment of movement, but little is known about the intersection between immunity and biomechanics.

Insights into Parental Care from Studies on Non-mammalian Vertebrates.

Parental care has attracted attention from both proximate and ultimate perspectives. While understanding the adaptive significance of care has been the focus of work in diverse organisms in behavioral ecology, most of what we know about the proximate mechanisms underlying parental care behavior comes from studies in mammals. Although studies on mammals have greatly improved our understanding of care, viewing parental care solely through a mammalian lens can limit our understanding.

Population-level variation in parasite resistance due to differences in immune initiation and rate of response.

Closely related populations often differ in resistance to a given parasite, as measured by infection success or failure. Yet, the immunological mechanisms of these evolved differences are rarely specified. Does resistance evolve via changes to the host's ability to recognize that an infection exists, actuate an effective immune response, or attenuate that response? We tested whether each of these phases of the host response contributed to threespine sticklebacks' recently evolved resistance to their tapeworm .

Microhabitat contributes to microgeographic divergence in threespine stickleback.

Since the New Synthesis, most migration-selection balance theory has predicted that there should be negligible differentiation over small spatial scales (relative to dispersal), because gene flow should erode any effect of divergent selection. Nevertheless, there are classic examples of microgeographic divergence, which theory suggests can arise under specific conditions: exceptionally strong selection, phenotypic plasticity in philopatric individuals, or nonrandom dispersal. Here, we present evidence of microgeographic morphological variation within lake and stream populations of threespine stickleback (Gasterosteus aculeatus).

Investigating the association between armour coverage and parasite infection in an estuarine population of stickleback.

Background: When threespine stickleback colonized fresh water, they repeatedly evolved reduced armour plating via changes in allele frequency. This evolution is typically attributed to differential predation pressure between marine and freshwater environments. However, the chromosomal region containing is associated with many other phenotypes, including schooling, antipredator behaviour, and immunity.