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1.
CBE Life Sci Educ ; 23(4): ar46, 2024 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-39324986

RESUMEN

"Bee the CURE" is a Power-of-Place course-based undergraduate research experience (PoP-CUREs; Jaeger et al., 2024) that combines place-based education (Demarest, 2014; Gruenewald, 2014) with CUREs, emphasizing student scientific civic engagement where research is relevant to the community where the research is taking place. PoP-CUREs have potential to build students' knowledge, skills, value, and self-efficacy when engaging with the public using science skills (i.e., scientific civic engagement). A mixed-methods sequential explanatory design utilizing surveys and semistructured interviews was used for this study (Warfa, 2016). Students made gains in science self-efficacy over the course of the semester and showed a trend of increasing science identity in both Fall 2021 and Spring 2022 semesters. Students' scientific civic knowledge, or a student's sense of how to use or apply knowledge and skills to help a community, increased significantly, while other predictors of scientific civic engagement started high and remained high throughout the course. Bee the CURE demonstrates psychosocial outcomes that are similar to previously studied CUREs and expands our understanding of how PoP-CUREs might influence outcomes with evidence that an important predictor of future scientific civic engagement increases. Implications for PoP-CURE instruction at Hispanic serving community colleges are discussed.


Asunto(s)
Ciencia , Autoeficacia , Estudiantes , Humanos , Universidades , Ciencia/educación , Masculino , Femenino , Adulto Joven , Curriculum , Encuestas y Cuestionarios
2.
Am J Bot ; 109(11): 1918-1938, 2022 11.
Artículo en Inglés | MEDLINE | ID: mdl-36380502

RESUMEN

PREMISE: Evolution of separate sexes from hermaphroditism often proceeds through gynodioecy, but genetic constraints on this process are poorly understood. Genetic (co-)variances and between-sex genetic correlations were used to predict evolutionary responses of multiple reproductive traits in a sexually dimorphic gynodioecious species, and predictions were compared with observed responses to artificial selection. METHODS: Schiedea (Caryophyllaceae) is an endemic Hawaiian lineage with hermaphroditic, gynodioecious, subdioecious, and dioecious species. We measured genetic parameters of Schiedea salicaria and used them to predict evolutionary responses of 18 traits in hermaphrodites and females in response to artificial selection for increased male (stamen) biomass in hermaphrodites or increased female (carpel, capsule) biomass in females. Observed responses over two generations were compared with predictions in replicate lines of treatments and controls. RESULTS: In only two generations, both stamen biomass in hermaphrodites and female biomass in females responded markedly to direct selection, supporting a key assumption of models for evolution of dioecy. Other biomass traits, pollen and ovule numbers, and inflorescence characters important in wind pollination evolved indirectly in response to selection on sex allocation. Responses generally followed predictions from multivariate selection models, with some responses unexpectedly large due to increased genetic correlations as selection proceeded. CONCLUSIONS: Results illustrate the power of artificial selection and utility of multivariate selection models incorporating sex differences. They further indicate that pollen and ovule numbers and inflorescence architecture could evolve in response to selection on biomass allocation to male versus female function, producing complex changes in plant phenotype as separate sexes evolve.


Asunto(s)
Caryophyllaceae , Flores , Animales , Flores/fisiología , Fitomejoramiento , Polinización , Caryophyllaceae/genética , Fenotipo
3.
Am J Bot ; 100(6): 1071-82, 2013 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-23703857

RESUMEN

PREMISE OF THE STUDY: Sex allocation models assume male and female traits are measured in a common currency, allocation traits show heritability, and tradeoffs between investment in the two sexual functions occur. The potential for model predictions and genetic parameters to depend on the currency used is not well understood, despite frequent use of measures not in a common currency. • METHODS: We analyzed the relationship between common currency (biomass of carpels, seeds, and stamens) measures and morphological measures (numbers of ovules, seeds, and pollen) in Schiedea salicaria (12-13% females) and S. adamantis (39% females), two closely related gynodioecious species. Additionally, we compared heritabilities and genetic correlations for male and female allocation between these two types of measures. • KEY RESULTS: Ovule, seed, and pollen number show greater sexual dimorphism in S. adamantis than in S. salicaria. Most but not all morphological traits and analogous biomass traits are highly correlated with a linear relationship. Narrow-sense heritabilities based on the two methods are often similar, but higher for ovule number than carpel mass and lower for anther number than stamen mass in S. adamantis. Neither trait type shows negative genetic correlations between male and female function. • CONCLUSIONS: Both trait types show greater sexual dimorphism in S. adamantis, and significant heritabilities suggest that morphological traits will continue to evolve with breeding system changes. Although most relationships between morphological and biomass traits are linear, curvilinear relationships for two traits suggest that caution is warranted if morphological and common currency traits are used interchangeably in fitness gain curves.


Asunto(s)
Caryophyllaceae/genética , Caryophyllaceae/fisiología , Flores/anatomía & histología , Evolución Biológica , Caryophyllaceae/clasificación , Flores/genética , Flores/fisiología , Regulación de la Expresión Génica de las Plantas/fisiología , Reproducción/genética , Reproducción/fisiología , Especificidad de la Especie
4.
Evolution ; 65(3): 757-70, 2011 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-21091465

RESUMEN

The evolution of sexual dimorphism depends in part on the additive genetic variance-covariance matrices within females, within males, and across the sexes. We investigated quantitative genetics of floral biomass allocation in females and hermaphrodites of gynodioecious Schiedea adamantis (Caryophyllaceae). The G-matrices within females (G(f)), within hermaphrodites (G(m)), and between sexes (B) were compared to those for the closely related S. salicaria, which exhibits a lower frequency of females and less-pronounced sexual dimorphism. Additive genetic variation was detected in all measured traits in S. adamantis, with narrow-sense heritability from 0.34-1.0. Female allocation and floral size traits covaried more tightly than did those traits with allocation to stamens. Between-sex genetic correlations were all <1, indicating sex-specific expression of genes. Common principal-components analysis detected differences between G(f) and G(m) , suggesting potential for further independent evolution of the sexes. The two species of Schiedea differed in G(m) and especially so in G(f) , with S. adamantis showing greater genetic variation in capsule mass and tighter genetic covariation between female allocation traits and flower size in females. Despite greater sexual dimorphism in S. adamantis, genetic correlations between the two sexes (standardized elements of B) were similar to correlations between sexes in S. salicaria.


Asunto(s)
Caryophyllaceae/genética , Variación Genética , Evolución Biológica , Caryophyllaceae/clasificación , Caryophyllaceae/fisiología , Flores/genética , Flores/fisiología
5.
Am J Bot ; 94(10): 1716-25, 2007 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-21636368

RESUMEN

Sexual dimorphism may be especially pronounced in wind-pollinated species because they lack the constraints of biotically pollinated species that must present their pollen and stigmas in similar positions to ensure pollen transfer. Lacking these constraints, the sexes of wind-pollinated species may diverge in response to the different demands of pollen dispersal and receipt, depending on the magnitude of genetic correlations preventing divergence between sexes. Patterns of sexual dimorphism and genetic variation were investigated for inflorescence traits in Schiedea adamantis (Caryophyllaceae), a species well adapted to wind-pollination, and compared to S. salicaria, a species with fewer adaptations to wind pollination. For S. adamantis, dimorphism was pronounced for inflorescence condensation and its components, including lateral flower number and pedicel length. Within sexes, genetic correlations between traits may constrain the relative shape of the inflorescence. Correlations detected across sexes may retard the evolution of sexual dimorphism in inflorescence structure, including features favoring enhanced dispersal and receipt of pollen. Despite genetic correlations across sexes, common principal components analysis showed that genetic variance-covariance matrices (G matrices) differed significantly between the sexes, in part because of greater genetic variation for flower number in hermaphrodites than in females. G matrices also differed between closely related S. adamantis and S. salicaria, indicating the potential for divergent evolution of inflorescence structure despite general similarities in morphology and pollination biology.

6.
New Phytol ; 169(3): 589-601, 2006.
Artículo en Inglés | MEDLINE | ID: mdl-16411961

RESUMEN

Evolution of dimorphic breeding systems may involve changes in ecophysiological traits as well as floral morphology because of greater resource demands on females. Differences between related species suggest that ecophysiological traits should be heritable, and species with higher female frequencies should show greater sexual differentiation. We used modified partial diallel crossing designs to estimate narrow-sense heritabilities and genetic correlations of sex-specific ecophysiological and morphological traits in closely related gynodioecious Schiedea salicaria (13% females) and Schiedea adamantis (39% females). In S. salicaria, hermaphrodites and females differed in photosynthetic rate and specific leaf area (SLA). Narrow-sense heritabilities were significant for stomatal conductance, SLA and inflorescence number in hermaphrodites, and for SLA and inflorescence number in females. Schiedea adamantis had no sexual dimorphism in measured traits; stomatal conductance, stem number and inflorescence number were heritable in females, and stem number was heritable in hermaphrodites. In both species, significant genetic correlations of traits between sexes were rare, indicating that traits can evolve independently in response to sex-differential selection. Significant genetic correlations were detected between certain traits within sexes of both species. Low heritability of some ecophysiological traits may reflect low additive genetic variability or high phenotypic plasticity in these traits.


Asunto(s)
Caryophyllaceae/genética , Variación Genética , Carbono/metabolismo , Caryophyllaceae/fisiología , Cruzamientos Genéticos , Flores/crecimiento & desarrollo , Luz , Fotosíntesis/fisiología , Hojas de la Planta/crecimiento & desarrollo , Transpiración de Plantas/fisiología , Caracteres Sexuales , Agua/metabolismo
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