Zach Culumber

Zach Culumber
University of Alabama in Huntsville | UAH · Department of Biological Sciences

PhD. Biology, Texas A&M

About

64
Publications
7,041
Reads
How we measure 'reads'
A 'read' is counted each time someone views a publication summary (such as the title, abstract, and list of authors), clicks on a figure, or views or downloads the full-text. Learn more
479
Citations
Additional affiliations
August 2007 - December 2011
Texas A&M University
Position
  • Research Assistant

Publications

Publications (64)
Article
Theory on indirect genetic effects (IGEs) indicates that variation in the genetic composition of social groups can generate GxG epistasis that may promote the evolution of stable polymorphisms. Using a livebearing fish with a genetic polymorphism in coloration and associated behavioral differences, we tested whether genotypes of social partners int...
Article
There has been widespread discussion of biases in the sciences. The extent of most forms of bias has scarcely been confronted with rigorous data. In the present article, we evaluated the potential for geographic, taxonomic, and citation biases in publications between temperate and tropical systems for nine broad topics in ecology and evolutionary b...
Article
The role of ecology in phenotypic and species diversification is widely documented. Nonetheless, numerous non-adaptive processes can shape realized niches and phenotypic variation in natural populations, complicating inferences about adaptive evolution at macroevolutionary scales. We tested for evolved differences in thermal tolerances and their as...
Article
Full-text available
Genetic variation is critical for adaptive evolution. Despite its importance, there is still limited evidence in support of some prominent theoretical models explaining the maintenance of genetic polymorphism within populations. We examined 84 populations of Xiphophorus variatus, a livebearing fish with a genetic polymorphism associated with physio...
Article
Theory predicts that environmental heterogeneity offers a potential solution to the maintenance of genetic variation within populations, but empirical evidence remains sparse. The livebearing fish Xiphophorus variatus exhibits polymorphism at a single locus, with different alleles resulting in up to five distinct melanistic “tailspot” patterns with...
Article
Full-text available
Variation in animal behavior can have important consequences for ecological processes like mate choice, resource competition and invasive potential. Characterizing behavioral variation across major environmental gradients can therefore provide insight into key ecological dynamics that govern the distribution and evolution of biodiversity. This stud...
Article
Full-text available
The intensity of ecological interactions is generally expected to increase at lower latitudes, suggesting potential to shape prey behavior at broad spatial scales. Yet, there is relatively limited understanding of how animal behavior varies across major environmental gradients for most taxonomic groups. In this study, I investigated behavioral resp...
Article
Full-text available
Characterizing the potential for, and mechanisms of, organismal response to environmental stress, particularly in the context of temperature, remains important for predicting effects of global change on natural populations. A number of studies have looked at changes in behavioral variation, focusing primarily on activity, boldness and aggression, w...
Article
Sexual conflict generates a reproductive arms race that often involves behavioural adaptations of females to avoid male sexual coercion. Given the cognitive demands underlying behavioural adaptations, it is surprising that there has been little exploration of whether sexual conflict plays an important role in the evolution of female brain size. Her...
Article
Full-text available
In the version of this Article originally published, some production notes starting "Should we change..." were mistakenly left in at the end of the section 'Sexual selection'; these notes have now been removed.
Article
Full-text available
Natural selection is often assumed to drive parallel functional diversification of the sexes. But males and females exhibit fundamental differences in their biology, and it remains largely unknown how sex differences affect macroevolutionary patterns. At microevolutionary scales, we understand how natural and sexual selection interact to give rise...
Article
Full-text available
Human activities alter ecosystems around the planet, often rendering environmental conditions unfavorable for plant and animal survival. In the salt marshes along North America's Atlantic coast, the influx of industrial waste has caused chemical pollutants to accumulate at lethal levels, causing the disappearance of many species from affected sites...
Article
Full-text available
Effective conservation measures for endangered species require basic knowledge of habitat use and critical environmental variables influencing the species' occurrence. However, setting priorities may be difficult when multiple endangered species inhabit the same area and differ in habitat use. This study characterized the physical and chemical envi...
Article
Full-text available
Vertebrate pigmentation is emerging as a powerful system for studying the evolution of adaptive traits and the maintenance of genetic and phenotypic variation in natural populations. Though melanism has been linked to physiological and behavioral traits in a variety of taxa, the generality of these associations for many taxa such as fishes remains...
Article
Full-text available
Background: Ecological factors often have a strong impact on spatiotemporal patterns of biodiversity. The integration of spatial ecology and phylogenetics allows for rigorous tests of whether speciation is associated with niche conservatism (constraints on ecological divergence) or niche divergence. We address this question in a genus of livebearin...
Article
Full-text available
Correlations among behavioral traits can generate trade-offs and constrain phenotypic evolution. Interspecific hybri-dization has the potential to alter behavioral trait correlations, but the effect of hybridization on suites of behavioral traits has received relatively little attention. We evaluated how natural hybridization changes the relationsh...
Article
Recognition and response to cues from conspecific and heterospecific individuals is critical to survival and reproduction and therefore should be learned early in life. Young fry of two live-bearing fishes, Poecilia mexicana and Xiphophorus birchmanni, were exposed to visual cues of three different species in order to measure shoal tightening, an a...
Article
Full-text available
Abstract Understanding the factors that give rise to natural hybrid zones and govern their dynamics and structure is important to predicting the evolutionary consequences of hybridization. Here we use a combination of multigenerational population genetic data, mating patterns from a natural population, behavioral assays, and mark-recapture data wit...
Article
Full-text available
Variation in pigmentation traits is an effective window to evolutionary processes due to their importance for survival and reproduction. In particular, one of the leading hypotheses for the maintenance of conspicuous pigmentation in natural populations is its signaling function in mate choice. Here, we demonstrate the occurrence of melanism in poec...
Article
Considerable attention has been given to the potential impacts of global climate change on biodiversity. In the present study, we combine understudied themes by examining the ability of a freshwater fish (polymorphic for heat-sensitivity) to respond to short-term thermal stress mimicking an extreme temperature event. We simultaneously measured the...
Article
Full-text available
The importance of genetic variation in evolution is well established. Yet, the mechanisms by which genetic variation—particularly variation in traits under selection—is maintained in natural populations has long been an evolutionary puzzle. Understanding individual variables driving selection and their functional mechanisms is increasingly importan...
Article
Full-text available
Abstract The genus Xiphophorus has great potential to contribute to the study of vertebrate pigmentation and elucidating the relative influence of ecology, physiology, and behavior on evolution at the molecular level. More importantly, the association between pigmentation and a functional oncogene offers the potential to understand the evolution an...
Article
Full-text available
Biosphere reserves have been established around the world as a means to protect sensitive or threatened ecoregions and the biodiversity within them. As such, the organisms occurring within these reserves are important from a conservation perspective as they often represent endemic species or remnant populations. Here we provide genetic evidence of...
Article
Full-text available
Negative assortative, or disassortative, mating describes the scenario when individuals tend to mate with dissimilar phenotypes more often than by random chance alone. This form of nonrandom mating has the power to select for the maintenance of polymorphism in conspicuous traits, for example, when females prefer mates that have a different trait va...
Article
Full-text available
Morphological symmetry is a correlate of fitness-related traits or even a direct target of mate choice in a variety of taxa. In these taxa, when females discriminate among potential mates, increased selection on males should reduce fluctuating asymmetry (FA). Hybrid populations of the swordtails Xiphophorus birchmanni and Xiphophorus malinche vary...
Article
Full-text available
The importance of genetic variation in evolution is well established. Yet, the mechanisms by which genetic variation - particularly variation in traits under selection - is maintained in natural populations has long been an evolutionary puzzle. Understanding individual variables driving selection and their functional mechanisms is increasingly impo...
Article
Full-text available
How do females decide which males to accept or reject as potential mates when the individuals encountered are unfamiliar and may be either heterospecifics or conspecifics? Learning often influences the development of mate preferences. Experience with particular phenotypes often positively biases preference for that phenotype. However, experience ca...
Article
Local adaptation is often invoked to explain hybrid zone structure, but empirical evidence of this is generally rare. Hybrid zones between two poeciliid fishes, Xiphophorus birchmanni and X. malinche, occur in multiple tributaries with independent replication of upstream-to-downstream gradients in morphology and allele frequencies. Ecological niche...
Article
Full-text available
Human-induced environmental change can affect the evolutionary trajectory of populations. In Mexico, indigenous Zoque people annually introduce barbasco, a fish toxicant, into the Cueva del Azufre to harvest fish during a religious ceremony. Here, we investigated tolerance to barbasco in fish from sites exposed and unexposed to the ritual. We found...
Article
Full-text available
Background: Predation is an important driver of life-history trait evolution. Fish predators may prey selectively on certain prey size classes, or pregnant females, particularly those of livebearing prey species. This selectivity ought to affect the evolutionary trajectory of the prey population. In sulphidic and hypoxic habitats, Atlantic mollies...
Article
Natural hybrid zones provide opportunities to study a range of evolutionary phenomena from speciation to the genetic basis of fitness-related traits. We show that widespread hybridization has occurred between two neo-tropical stream fishes with partial reproductive isolation. Phylogenetic analyses of mitochondrial sequence data showed that the swor...
Article
Full-text available
Ultraviolet radiation—the primary natural pollutant affecting melanomagenesis—may represent a widespread ecological stressor for many fishes, and yet the relationship between UV-exposure and stress has not been investigated in natural fish populations. Recent lab-based studies have sought to characterize the relationship between tumorigenesis and t...
Article
It is empirically known that anionic polyelectrolytes present in cystic fibrosis (CF) airways due to bacterial infection significantly decrease the activity of cationic antimicrobials via electrostatic binding. In this work, we use synchrotron small-angle X-ray scattering to investigate the interaction between tobramycin, an aminoglycoside antibiot...

Network

Cited By