Lack of an association between heterozygosity and growth rate in the wood frog, Rana sylvatica

1995 ◽  
Vol 73 (3) ◽  
pp. 569-575 ◽  
Author(s):  
Michael F. Wright ◽  
Sheldon I. Guttman
Keyword(s):  
Growth Rate ◽  
Multiple Regression ◽  
Rana Sylvatica ◽  
Developmental Period ◽  
Wood Frog ◽  
Single Locus ◽  
Regression Analyses ◽  
Enzyme Loci ◽  
Effect On Growth

The effect of both multilocus and single-locus heterozygosity on growth rate was examined in a cohort of larvae of the wood frog, Rana sylvatica, collected from a pond during the later stages of premetamorphic development. Seven electrophoretically detected enzyme loci were used to determine individual heterozygosity, whereas the growth rate was measured as wet mass. In all cases, no significant correlation was found between multilocus heterozygosity and mass among larvae collected at intervals during the developmental period. In addition, multiple regression analyses indicated that no single locus had a demonstrable effect on growth rate. The results of this study, therefore, provide no evidence for a link between enzyme heterozygosity and growth rate during the later stages of premetamorphic development in wood frog larvae.

scholarly journals Species loss in developed landscapes: an experimental evaluation

2014 ◽  
Author(s):  
Alex Shepack ◽  
Kealoha Freidenburg ◽  
David Skelly
Keyword(s):  
Growth Rate ◽  
Experimental Evaluation ◽  
Rana Sylvatica ◽  
Development Rate ◽  
Wood Frog ◽  
Species Loss ◽  
Landscape Development ◽  
Wood Frogs ◽  
Lithobates Sylvaticus ◽  
Human Use

Conversion of landscapes for human uses is widely associated with loss of biodiversity. Here we focus on limits to distribution defined by intensity of landscape development. Using a translocation experiment, we ask does degradation of wetland habitat contribute to species loss? Wood frog larvae (Rana sylvatica = Lithobates sylvaticus), were reared within enclosures in 7 ponds harboring populations of wood frogs and in 5 ponds where they are absent. Survival, growth rate, and development rate were equivalent between ‘present’ and ‘absent’ ponds. While it is clear that landscapes surrounding ‘absent’ ponds had been heavily influenced by human use, we find no evidence that such wetlands provide inferior habitat for wood frog recruitment. Their absence in human altered landscapes may stem from influences outside of pond basins. The results provide a caution to the typically unexamined presumption that relictual habitats in developed landscapes are degraded in their utility for wildlife.

scholarly journals Species loss in developed landscapes: an experimental evaluation

2014 ◽  
Author(s):  
Alex Shepack ◽  
Kealoha Freidenburg ◽  
David Skelly
Keyword(s):  
Growth Rate ◽  
Experimental Evaluation ◽  
Rana Sylvatica ◽  
Development Rate ◽  
Wood Frog ◽  
Species Loss ◽  
Landscape Development ◽  
Wood Frogs ◽  
Lithobates Sylvaticus ◽  
Human Use

Conversion of landscapes for human uses is widely associated with loss of biodiversity. Here we focus on limits to distribution defined by intensity of landscape development. Using a translocation experiment, we ask does degradation of wetland habitat contribute to species loss? Wood frog larvae (Rana sylvatica = Lithobates sylvaticus), were reared within enclosures in 7 ponds harboring populations of wood frogs and in 5 ponds where they are absent. Survival, growth rate, and development rate were equivalent between ‘present’ and ‘absent’ ponds. While it is clear that landscapes surrounding ‘absent’ ponds had been heavily influenced by human use, we find no evidence that such wetlands provide inferior habitat for wood frog recruitment. Their absence in human altered landscapes may stem from influences outside of pond basins. The results provide a caution to the typically unexamined presumption that relictual habitats in developed landscapes are degraded in their utility for wildlife.

Language and Literacy Predictors of Dialect Density Among School-Age African American Children From Two Geographic Regions

2020 ◽  
Vol 51 (3) ◽  
pp. 807-820
Author(s):  
Lena G. Caesar ◽  
Marie Kerins
Keyword(s):  
African American ◽  
Multiple Regression ◽  
Oral Language ◽  
East Coast ◽  
Geographic Region ◽  
Literacy Skills ◽  
School Age ◽  
Regression Analyses ◽  
Geographic Regions ◽  
American Children

Purpose The purpose of this study was to investigate the relationship between oral language, literacy skills, age, and dialect density (DD) of African American children residing in two different geographical regions of the United States (East Coast and Midwest). Method Data were obtained from 64 African American school-age children between the ages of 7 and 12 years from two geographic regions. Children were assessed using a combination of standardized tests and narrative samples elicited from wordless picture books. Bivariate correlation and multiple regression analyses were used to determine relationships to and relative contributions of oral language, literacy, age, and geographic region to DD. Results Results of correlation analyses demonstrated a negative relationship between DD measures and children's literacy skills. Age-related findings between geographic regions indicated that the younger sample from the Midwest outscored the East Coast sample in reading comprehension and sentence complexity. Multiple regression analyses identified five variables (i.e., geographic region, age, mean length of utterance in morphemes, reading fluency, and phonological awareness) that accounted for 31% of the variance of children's DD—with geographic region emerging as the strongest predictor. Conclusions As in previous studies, the current study found an inverse relationship between DD and several literacy measures. Importantly, geographic region emerged as a strong predictor of DD. This finding highlights the need for a further study that goes beyond the mere description of relationships to comparing geographic regions and specifically focusing on racial composition, poverty, and school success measures through direct data collection.

THE EVALUATION OF SELF-MONITORING ATTRIBUTES

1991 ◽  
Vol 19 (3) ◽  
pp. 205-215 ◽  
Author(s):  
Arts Jiujias ◽  
Peter Horvath
Keyword(s):  
Regression Analysis ◽  
Multiple Regression Analysis ◽  
Multiple Regression ◽  
Regression Analyses ◽  
Self Monitoring

Eighty-six Canadian female undergraduates attributed self-monitoring traits to a target presented on videotape, and evaluated her in terms of liking. Attributed self-monitoring was negatively correlated with attraction to the target and was the only predictor of attraction in a multiple regression analysis. Multiple regression analyses with subscales of attributed self-monitoring as predictors suggested that the evaluations may be the result of the attributed unpredictability of the high self-monitoring prototype.

Phenotypic selection in a population of Crepis tectorum ssp. pumila (Asteraceae)

1992 ◽  
Vol 70 (1) ◽  
pp. 89-95 ◽  
Author(s):  
Stefan Andersson
Keyword(s):  
Life History ◽  
Multiple Regression ◽  
Large Scale ◽  
Demographic Data ◽  
Phenotypic Selection ◽  
Direct Selection ◽  
Surprising Result ◽  
Regression Analyses ◽  
Ecotypic Differentiation ◽  
Crepis Tectorum

A 3-year demographic study was conducted to reveal targets of selection on morphology and life history in a population of Crepis tectorum ssp. pumila, a winter annual plant confined to calcareous grasslands (alvars) on the Baltic island of Öland (south Sweden). I calculated the selection differential to describe the change in the mean value of a character due to selection and used multiple regression analyses to partition the direct effect of selection on the trait from indirect responses of selection on other traits. Rosette leaf number, a convenient measure of plant size, was strongly correlated with both viability and fertility (fitness). There was also a strong relationship between fitness and the extent to which the plants expressed traits characterizing this particular taxon. Multiple regression analyses indicated direct selection favouring plants with deeply lobed leaves and a densely branched stem, two distinctive traits of ssp. pumila believed to be adaptive in the alvar habitat. Only stem height was subject to both direct and indirect selection in the wrong direction; taller individuals were more successful than those with a shorter stem, a surprising result considering the inferred advantage of a short stature in the exposed alvar habitat. Selection on other traits assumed to be ecologically important (germination time, flowering time, and seed size) was found to be either absent or variable in direction when other traits were held constant. The failure of plants to survive to the flowering stage in the last two summers indicates strong selection for plants that produce a high percentage of dormant seeds. Overall, the contemporary selection regime as revealed by demographic data was only partly congruent with predictions regarding historical selection pressures based on large-scale patterns of variation (ecotypic differentiation). Key words: Crepis tectorum, ecotypic differentiation, life history, morphology, phenotypic selection.

Growth of the Wood Frog, Rana sylvatica

Copeia ◽  
1961 ◽  
Vol 1961 (1) ◽  
pp. 74 ◽  
Author(s):  
Edward D. Bellis
Keyword(s):  
Rana Sylvatica ◽  
Wood Frog

Distribution of the middorsal stripe dimorphism in the wood frog, Rana sylvatica, in eastern North America

1980 ◽  
Vol 58 (9) ◽  
pp. 1643-1651 ◽  
Author(s):  
Frederick W. Schueler ◽  
Francis R. Cook
Keyword(s):  
United States ◽  
North America ◽  
Rana Sylvatica ◽  
Wood Frog ◽  
Eastern North America ◽  
Hudson Bay ◽  
Northeastern United States ◽  
Southern Ontario ◽  
Maritime Canada ◽  
Eurasian Species

The frequency of the middorsally striped morph of Rana sylvatica in Ontario and Manitoba varies from absence in southern Ontario to 80% on the coast of Hudson Bay, with a general value of 20–30% in the boreal forest, a rise to 50% on the forest–grassland ecotone in southern Manitoba, and a decline westward to 20% on the edge of the prairies. This morph is rare in the northeastern United States and Maritime Canada. The suggested relationship between its frequency and the "grassiness" of the background on which predators view it is reexamined, and it is suggested that a linkage with earlier transformation as demonstrated in Eurasian species may explain certain anomalies.

Copying, Reading, and Writing of Kana and Simple Forms by Japanese Preschoolers

1988 ◽  
Vol 66 (2) ◽  
pp. 387-394
Author(s):  
Jun Yamada ◽  
Miyuki Sasaki ◽  
Naoko Motooka
Keyword(s):  
Multiple Regression ◽  
Good Predictor ◽  
Quality Measure ◽  
Writing Achievement ◽  
Regression Analyses ◽  
Reading And Writing ◽  
Conventional Form ◽  
Form Quality ◽  
Japanese Kana ◽  
Children's Reading

42 Japanese preschoolers were administered tasks of copying, reading, and writing of Japanese kana (cursive syllabic letters) and simple forms. Multiple regression analyses were used to determine whether two kana-copying measures, speed and span, make significant contributions to children's reading and writing achievement after a conventional form-quality measure had been controlled. Analysis showed that speed or span accounts uniquely for a significant and sizable amount of the variance of reading and writing, suggesting that kana-copying is a good predictor of reading and writing for Japanese preschoolers.

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