Ecology and Evolutionary Biology Commons^™

Is The Life History Flexibility Of Cold Desert Annuals Broad Enough To Cope With Predicted Climate Change? The Case Of Erodium Oxyrhinchum In Central Asia, Huiliang Liu, Yanfeng Chen, Lingwei Zhang, Jerry M. Baskin, Carol C. Baskin, Lan Zhang, Yan Liu, Daoyuan Zhang, Yuanming Zhang

Biology Faculty Publications

Interannual seasonal variability in precipitation may strongly affect the life history and growth of desert annual plants. We compared the effects of dry and wet springs and dry and wet autumns on growth and F2 seed dormancy of plants from spring (SG)- and autumn (AG)-germinated seeds of the cold desert annual Erodium oxyrhinchum. Vegetative and reproductive growth and F2 seed dormancy and germination were monitored from September 2016 to November 2020 in the sandy Gurbantunggut Desert in NW China in Central Asia. Dry autumns decreased the density of AG plants, and dry springs decreased the density of SG plants …

Highly Contiguous Assemblies Of 101 Drosophilid Genomes, Bernard Y. Kim, Jeremy R. Wang, Danny E. Miller, Olga Barmina, Emily Delaney, Ammon Thompson, Aaron A. Comeault, David Peede, Emmanuel R. R. D'Agostino, Julianne Pelaez, Jessica M. Aguilar, Diler Haji, Teruyuki Matsunaga, Ellie E. Armstrong, Molly Zych, Yoshitaka Ogawa, Marina Stamenković-Radak, Mihailo Jelić, Marija Savić Veselinović, Marija Tanasković, Jeremy S. Davis

Biology Faculty Publications

Over 100 years of studies in Drosophila melanogaster and related species in the genus Drosophila have facilitated key discoveries in genetics, genomics, and evolution. While high-quality genome assemblies exist for several species in this group, they only encompass a small fraction of the genus. Recent advances in long-read sequencing allow high-quality genome assemblies for tens or even hundreds of species to be efficiently generated. Here, we utilize Oxford Nanopore sequencing to build an open community resource of genome assemblies for 101 lines of 93 drosophilid species encompassing 14 species groups and 35 sub-groups. The genomes are highly contiguous and complete, …

Fgf-Signaling Is Compartmentalized Within The Mesenchyme And Controls Proliferation During Salamander Limb Development, Sruthi Purushothaman, Ahmed Elewa, Ashley W. Seifert

Biology Faculty Publications

Although decades of studies have produced a generalized model for tetrapod limb development, urodeles deviate from anurans and amniotes in at least two key respects: their limbs exhibit preaxial skeletal differentiation and do not develop an apical ectodermal ridge (AER). Here, we investigated how Sonic hedgehog (Shh) and Fibroblast growth factor (Fgf) signaling regulate limb development in the axolotl. We found that Shh-expressing cells contributed to the most posterior digit, and that inhibiting Shh-signaling inhibited Fgf8 expression, anteroposterior patterning, and distal cell proliferation. In addition to lack of a morphological AER, we found that salamander …

Amplicon Sequencing Of 42 Nuclear Loci Supports Directional Gene Flow Between South Pacific Populations Of A Hydrothermal Vent Limpet, Sophie Plouviez, Abigail Leavitt Labella, David W. Weisrock, F. A. Bastiaan Von Meijenfeldt, Bernard Ball, Joseph E. Neigel, Cindy L. Van Dover

Biology Faculty Publications

In the past few decades, population genetics and phylogeographic studies have improved our knowledge of connectivity and population demography in marine environments. Studies of deep‐sea hydrothermal vent populations have identified barriers to gene flow, hybrid zones, and demographic events, such as historical population expansions and contractions. These deep‐sea studies, however, used few loci, which limit the amount of information they provided for coalescent analysis and thus our ability to confidently test complex population dynamics scenarios.

In this study, we investigated population structure, demographic history, and gene flow directionality among four Western Pacific hydrothermal vent populations of the vent limpet Lepetodrilus …

Effects Of Increased Precipitation On The Life History Of Spring- And Autumn-Germinated Plants Of The Cold Desert Annual Erodium Oxyrhynchum (Geraniaceae), Yanfeng Chen, Xiang Shi, Lingwei Zhang, Jerry M. Baskin, Carol C. Baskin, Huiliang Liu, Daoyuan Zhang

Biology Faculty Publications

Future increased precipitation in cold desert ecosystems may impact annual/ephemeral plant species that germinate in both spring and autumn. Our primary aim was to compare the life history characteristics of plants from spring-germinating (SG) and autumn-germinating (AG) seeds of Erodium oxyrhynchum. Plants in field plots with simulated increases in precipitation of 0, 30 and 50 % in spring and summer were monitored to determine seedling survival, phenology, plant size, seed production and biomass accumulation and allocation. Germination characteristics were determined in the laboratory for seeds produced by plants in all increased precipitation treatments. Increased precipitation in spring significantly improved survival …

Seed Germination Responses To Seasonal Temperature And Drought Stress Are Species‐Specific But Not Related To Seed Size In A Desert Steppe: Implications For Effect Of Climate Change On Community Structure, Fengyan Yi, Zhaoren Wang, Carol C. Baskin, Jerry M. Baskin, Ruhan Ye, Hailian Sun, Yuanyuan Zhang, Xuehua Ye, Guofang Liu, Xuejun Yang, Zhenying Huang

Biology Faculty Publications

Investigating how seed germination of multiple species in an ecosystem responds to environmental conditions is crucial for understanding the mechanisms for community structure and biodiversity maintenance. However, knowledge of seed germination response of species to environmental conditions is still scarce at the community level. We hypothesized that responses of seed germination to environmental conditions differ among species at the community level, and that germination response is not correlated with seed size. To test this hypothesis, we determined the response of seed germination of 20 common species in the Siziwang Desert Steppe, China, to seasonal temperature regimes (representing April, May, June, …

Miniscule Differences Between Sex Chromosomes In The Giant Genome Of A Salamander, Melissa C. Keinath, Nataliya Y. Timoshevskaya, Vladimir A. Timoshevskiy, S. Randal Voss, Jeramiah J. Smith

Biology Faculty Publications

In the Mexican axolotl (Ambystoma mexicanum), sex is determined by a single Mendelian factor, yet its sex chromosomes do not exhibit morphological differentiation typical of many vertebrate taxa that possess a single sex-determining locus. As sex chromosomes are theorized to differentiate rapidly, species with undifferentiated sex chromosomes provide the opportunity to reconstruct early events in sex chromosome evolution. Whole genome sequencing of 48 salamanders, targeted chromosome sequencing and in situ hybridization were used to identify the homomorphic sex chromosome that carries an A. mexicanum sex-determining factor and sequences that are present only on the W chromosome. Altogether, …

Meta-Analysis Challenges A Textbook Example Of Status Signalling And Demonstrates Publication Bias, Alfredo Sánchez-Tójar, Shinichi Nakagawa, Moisès Sánchez-Fortún, Dominic A. Martin, Sukanya Ramani, Antje Girndt, Veronika Bókony, Bart Kempenaers, András Liker, David F. Westneat, Terry Burke, Julia Schroeder

Biology Faculty Publications

The status signalling hypothesis aims to explain within-species variation in ornamentation by suggesting that some ornaments signal dominance status. Here, we use multilevel meta-analytic models to challenge the textbook example of this hypothesis, the black bib of male house sparrows (Passer domesticus). We conducted a systematic review, and obtained primary data from published and unpublished studies to test whether dominance rank is positively associated with bib size across studies. Contrary to previous studies, the overall effect size (i.e. meta-analytic mean) was small and uncertain. Furthermore, we found several biases in the literature that further question the support available …

The Evolutionary History Of Nebraska Deer Mice: Local Adaptation In The Face Of Strong Gene Flow, Susanne P Pfeifer, Stefan Laurent, Vitor C. Sousa, Catherine R. Linnen, Matthieu Foll, Laurent Excoffier, Hopi E. Hoekstra, Jeffrey D. Jensen

Biology Faculty Publications

The interplay of gene flow, genetic drift, and local selective pressure is a dynamic process that has been well studied from a theoretical perspective over the last century. Wright and Haldane laid the foundation for expectations under an island-continent model, demonstrating that an island-specific beneficial allele may be maintained locally if the selection coefficient is larger than the rate of migration of the ancestral allele from the continent. Subsequent extensions of this model have provided considerably more insight. Yet, connecting theoretical results with empirical data has proven challenging, owing to a lack of information on the relationship between genotype, phenotype, …

Effect Of Population, Collection Year, After-Ripening And Incubation Condition On Seed Germination Of Stipa Bungeana, Rui Zhang, Jerry M. Baskin, Carol C. Baskin, Qing Mo, Lijun Chen, Xiaowen Hu, Yanrong Wang

Biology Faculty Publications

Knowledge of the germination behavior of different populations of a species can be useful in the selection of appropriate seed sources for restoration. The aim of this study was to test the effect of seed population, collection year, after-ripening and incubation conditions on seed dormancy and germination of Stipa bungeana, a perennial grass used for revegetation of degraded grasslands on the Loess Plateau, China. Fresh S. bungeana seeds were collected from eight locally-adapted populations in 2015 and 2016. Dormancy and germination characteristics of fresh and 6-month-old dry-stored seeds were determined by incubating them over a range of alternating temperature …

Seedling Tolerance To Cotyledon Removal Varies With Seed Size: A Case Of Five Legume Species, Xiao Wen Hu, Rui Zhang, Yan Pei Wu, Carol C. Baskin

Biology Faculty Publications

It is generally accepted that seedlings from large seeds are more tolerant to defoliation than those from small seeds due to the additional metabolic reserves present in the large seeds. However, information on the effects of amount of seed reserves (cotyledon removal) from seedlings resulting from large vs. small seeds on seedling growth and long-term survival in the field is limited. Five legume species with different sizes of seeds were sown in the field and none, one, or both cotyledons removed 7 days after seedling emergence. Seedling biomass, relative growth rate (RGR) and survival were determined at different time. Cotyledon …

Divergence In Life History Traits Between Two Populations Of A Seed-Dimorphic Halophyte In Response To Soil Salinity, Fan Yang, Jerry M. Baskin, Carol C. Baskin, Xuejun Yang, Dechang Cao, Zhenying Huang

Biology Faculty Publications

Production of heteromorphic seeds is common in halophytes growing in arid environments with strong spatial and temporal heterogeneity. However, evidence for geographic variation (reflecting local adaptation) is almost nonexistent. Our primary aims were to compare the life history traits of two desert populations of this halophytic summer annual Suaeda corniculata subsp. mongolica and to investigate the phenotypic response of its plant and heteromorphic seeds to different levels of salt stress. Dimorphic seeds (F₁) of the halophyte S. corniculata collected from two distant populations (F₀) that differ in soil salinity were grown in a common environment under …

Gregariousness Does Not Vary With Geography, Developmental Stage, Or Group Relatedness In Feeding Redheaded Pine Sawfly Larvae, John W. Terbot Ii, Ryan L. Gaynor, Catherine R. Linnen

Biology Faculty Publications

Aggregations are widespread across the animal kingdom, yet the underlying proximate and ultimate causes are still largely unknown. An ideal system to investigate this simple, social behavior is the pine sawfly genus Neodiprion, which is experimentally tractable and exhibits interspecific variation in larval gregariousness. To assess intraspecific variation in this trait, we characterized aggregative tendency within a single widespread species, the redheaded pine sawfly (N. lecontei). To do so, we developed a quantitative assay in which we measured interindividual distances over a 90-min video. This assay revealed minimal behavioral differences: (1) between early-feeding and late-feeding larval instars, …

Effect Of Seed Position On Parental Plant On Proportion Of Seeds Produced With Nondeep And Intermediate Physiological Dormancy, Juan J. Lu, Dun Y. Tan, Carol C. Baskin, Jerry M. Baskin

Biology Faculty Publications

The position in which seeds develop on the parental plant can have an effect on dormancy-break and germination. We tested the hypothesis that the proportion of seeds with intermediate physiological dormancy (PD) produced in the proximal position on a raceme of Isatis violascens plants is higher than that produced in the distal position, and further that this difference is related to temperature during seed development. Plants were watered at 3-day intervals, and silicles and seeds from the proximal (early) and distal (late) positions of racemes on the same plants were collected separately and tested for germination. After 0 and 6 …

Oviposition Traits Generate Extrinsic Postzygotic Isolation Between Two Pine Sawfly Species, Emily E. Bendall, Kim L. Vertacnik, Catherine R. Linnen

Biology Faculty Publications

Background: Although empirical data indicate that ecological speciation is prevalent in nature, the relative importance of different forms of reproductive isolation and the traits generating reproductive isolation remain unclear. To address these questions, we examined a pair of ecologically divergent pine-sawfly species: while Neodiprion pinetum specializes on a thin-needled pine (Pinus strobus), N. lecontei utilizes thicker-needled pines. We hypothesized that extrinsic postzygotic isolation is generated by oviposition traits. To test this hypothesis, we assayed ovipositor morphology, oviposition behavior, and host-dependent oviposition success in both species and in F1 and backcross females.

Results: Compared to N. lecontei, N. …

Effect Of Seed Morph And Light Level On Growth And Reproduction Of The Amphicarpic Plant Amphicarpaea Edgeworthii (Fabaceae), Keliang Zhang, Jerry M. Baskin, Carol C. Baskin, Xuejun Yang, Zhenying Huang

Biology Faculty Publications

Amphicarpic plants produce aerial and subterranean fruits on an individual plant, and these heteromorphic diaspores give rise to plants that differ in growth and ecology. Amphicarpaea edgeworthii is a summer annual amphicarpic species that grows over a range of light levels. We aimed to compare the response to shading intensity of plants of A. edgeworthii grown throughout their life cycle from aerial seeds (ASP) and from subterranean seeds (SSP). We hypothesized that vegetative and reproductive growth of plants from ASP and SSP respond differently to light. Plants were grown from ASP and SSP under 0, 46, 71 and 90% shading …

Microarray Analysis Of A Salamander Hopeful Monster Reveals Transcriptional Signatures Of Paedomorphic Brain Development, Robert B. Page, Meredith A. Boley, Jeramiah J. Smith, Srikrishna Putta, Stephen R. Voss

Biology Faculty Publications

BACKGROUND: The Mexican axolotl (Ambystoma mexicanum) is considered a hopeful monster because it exhibits an adaptive and derived mode of development - paedomorphosis - that has evolved rapidly and independently among tiger salamanders. Unlike related tiger salamanders that undergo metamorphosis, axolotls retain larval morphological traits into adulthood and thus present an adult body plan that differs dramatically from the ancestral (metamorphic) form. The basis of paedomorphic development was investigated by comparing temporal patterns of gene transcription between axolotl and tiger salamander larvae (Ambystoma tigrinum tigrinum) that typically undergo a metamorphosis.

RESULTS: Transcript abundances from whole brain and pituitary were estimated …

Rapid Fixation Of Non-Native Alleles Revealed By Genome-Wide Snp Analysis Of Hybrid Tiger Salamanders, Benjamin M. Fitzpatrick, Jarrett R. Johnson, D. Kevin Kump, H. Bradley Shaffer, Jeramiah J. Smith, S. Randal Voss

Biology Faculty Publications

BACKGROUND: Hybrid zones represent valuable opportunities to observe evolution in systems that are unusually dynamic and where the potential for the origin of novelty and rapid adaptation co-occur with the potential for dysfunction. Recently initiated hybrid zones are particularly exciting evolutionary experiments because ongoing natural selection on novel genetic combinations can be studied in ecological time. Moreover, when hybrid zones involve native and introduced species, complex genetic patterns present important challenges for conservation policy. To assess variation of admixture dynamics, we scored a large panel of markers in five wild hybrid populations formed when Barred Tiger Salamanders were introduced into …

Maptogenome: A Comparative Genomic Tool That Aligns Transcript Maps To Sequenced Genomes, Srikrishna Putta, Jeramiah J. Smith, Chuck Staben, S. Randal Voss

Biology Faculty Publications

Efforts to generate whole genome assemblies and dense genetic maps have provided a wealth of gene positional information for several vertebrate species. Comparing the relative location of orthologous genes among these genomes provides perspective on genome evolution and can aid in translating genetic information between distantly related organisms. However, large-scale comparisons between genetic maps and genome assemblies can prove challenging because genetic markers are commonly derived from transcribed sequences that are incompletely and variably annotated. We developed the program MapToGenome as a tool for comparing transcript maps and genome assemblies. MapToGenome processes sequence alignments between mapped transcripts and whole genome …