David Punzalan

University of Victoria | UVIC · Department of Biology

Life-history variation plays a central role in evolutionary and ecological processes and might be especially pertinent to divergence in closely related species. We investigated differences in life history in a pair of parapatric species of ambush bugs (Phymata) and a putative hybrid population. Despite the evidence of gene flow among these species,...

Aim A universal attribute of species is that their distributions are limited by numerous factors that may be difficult to quantify. Furthermore, climate change‐induced range shifts have been reported in many taxa, and understanding the implications of these shifts remains a priority and a challenge. Here, we use Maxent to predict current suitable h...

PREPRINT. Full text here: https://www.researchgate.net/publication/344671383_Climate_change_has_different_predicted_effects_on_the_range_shifts_of_two_hybridizing_ambush_bug_Phymata_Family_Reduviidae_Order_Hemiptera_species

Phenotypic evolution through deep time is slower than expected from microevolutionary rates. This is the paradox of stasis. Previous models suggest stasis occurs because populations track adaptive peaks that typically move on million-year intervals, raising the equally perplexing question of why peaks shifts are so rare. Here, we consider the possi...

Anisogamy predisposes the sexes to very different patterns of selection on shared traits. Selective differences between the sexes may manifest as changes in the direction or strength of selection acting on shared phenotypes. Although previous studies have found evidence for widespread differences in the direction of selection between the sexes, sur...

1. The persistence of both geographical and reproductive boundaries between related species poses a fundamental puzzle in biology. Reproductive interactions between species can have a substantial impact on the maintenance of a boundary, potentially contributing to its collapse (e.g. via hybridisation) or facilitating reproductive isolation (e.g. vi...

Empirical studies show that lineages typically exhibit long periods of evolutionary stasis and that relative levels of within-species trait covariance often correlate with the extent of between-species trait divergence. These observations have been interpreted by some as evidence of genetic constraints persisting for long periods of time. However,...

Female ornaments have evolved in a few taxa in which females compete for access to important resources provided by their mates. However, the effects of these sexually selected traits on survival have not been studied. Elaborate leg-scale and/or abdominal ornaments are displayed by females of some Rhamphomyia dance flies (Diptera: Empididae) to flyi...

Sexual dimorphism is a consequence of both sex-specific selection and potential constraints imposed by a shared genetic architecture underlying sexually homologous traits. However, genetic architecture is expected to evolve to mitigate these constraints, allowing the sexes to approach their respective optimal mean phenotype. In additon, sex-specifi...

Sexually antagonistic genetic variation can pose limits to the independent evolution and adaptation of the sexes. The extent of sexually antagonistic variation is reflected in the intersex genetic correlation for fitness (rw(FM)). Previous estimates of this correlation have been mostly limited to populations in environments to which they are alread...

Ecological variables can exert considerable influence on the dynamics of mating systems, determining the population mean and variance in mating success. Sex‐specific daily estimates of mating frequency in a wild population of Phymata americana Melin were determined and the way in which these covaried with three ecological variables was evaluated. A...

The potential for evolutionary change is limited by the availability of genetic variation. Mutations are the ultimate source of new alleles, yet there have been few experimental investigations of the role of novel mutations in multivariate phenotypic evolution. Here, we evaluated the degree of multivariate phenotypic divergence observed in a long-t...

Three-dimensional plots of phenotypic divergence of lineages evolved under small (open circles) and large (closed squares) bottleneck treatments with respect to the ancestral phenotype (marked as an “x” and placed at the origin, denoted by a dashed line). Trait distances (in units of standard deviations) are for biomass (BM), colony forming units (...

Targets of selection during experimental evolution. (DOC)

Model system. (DOC)

Parameter estimates and corresponding effects from linear mixed model regression of adaptation on population size treatment and traits. (DOC)

Fungal populations can adapt to their environment by the generation and fixation of spontaneous beneficial mutations. In this study we examined whether adaptation, measured as an increased mycelial growth rate, has correlated responses in the filamentous fungus Aspergillus nidulans with several other metric characters that could be important fitnes...

Sex differences often call sexual selection to mind; however, a new damselfly study cautions on being too hasty, and implicates viability selection in the evolution of male and female colouration.

A widely held view is that the strength and form of natural selection varies in time and space in response to varying ecological forces; however, adequate quantitative evaluations of this are relatively scarce. In this study, we measured the strength and form of sexual selection acting on a suite of male morphological traits in a wild ambush bug (P...

Sexually selected traits, while advantageous in terms of mating success, are expected to carry considerable costs in terms of viability selection. The ambush bug Phymata americana exhibits a peculiar sexual dimorphism in colour pattern where males express sex-specific patches of dark colour pattern. Previous work has demonstrated that this dimorphi...

Female mate-choice copying is a social learning phenomenon whereby a female's observation of a successful sexual interaction between a male and another female increases her likelihood of subsequently preferring that male. Although mate-choice copying has been documented in several vertebrate species, to our knowledge it has not yet been investigate...

In the field, phenotypic determinants of competitive success are not always absolute. For example, contest experience may alter future competitive performance. As future contests are not determined solely on phenotypic attributes, prior experience could also potentially alter phenotype-fitness associations. In this study, we examined the influence...

Assessment strategies are an important component in game theoretical models of contests. Strategies can be either based on one's own abilities (self assessment) or on the relative abilities of two opponents (mutual assessment). Using statistical methodology that allows discrimination between assessment types, we examined contests in the jumping spi...

Sexually selected traits that are costly are predicted to be more condition dependent than nonsexually selected traits. Assuming resource limitation, increased allocation to a sexually selected trait may also come at a cost to other fitness components. To test these predictions, we varied adult food ration to manipulate condition in the colour dimo...

Sexual selection is a potent evolutionary force often invoked to explain observed cases of sexual dimorphism. However, evidence of this process operating on existing phenotypic variation is limited. We investigated whether sexual selection could account for sexual dimorphism in size and color pattern in the ambush bug Phymata americana. We consider...

Sexual dimorphism in coloration is a taxonomically widespread phenomenon often attributed to sexual selection on visual signals. However, the ambush bug Phymata americana exhibits sexual dimorphism in coloration that has no apparent signalling function. Here we provide evidence that colour pattern in this species influences male mating success indi...

The maintenance of genetic variation in traits under natural selection is a long-standing paradox in evolutionary biology. Of the processes capable of maintaining variation, negative frequency-dependent selection (where rare types are favoured by selection) is the most powerful, at least in theory; however, few experimental studies have confirmed t...

One of the key challenges of both ecology and evolutionary biology is to understand the mechanisms that maintain diversity. Negative frequency-dependent selection is a powerful mechanism for maintaining variation in the population as well as species diversity in the community. There are a number of studies showing that this type of selection, where...

The vast majority of tested juvenile crayfish of Fallicambarus fodiens consistently preferred conspecific-built mud chimneys over similar-looking human-built chimneys. When the chimneys were surrounded by transparent acetate sheets, the crayfish no longer discriminated between conspecific-built and human-built chimneys. This suggests that visual cu...