Evolution of song complexity in Bengalese finches: Sexual selection and domestication as two factors

2015 ◽  
Vol 138 (3) ◽  
pp. 1880-1880 ◽  
Author(s):  
Kazuo Okanoya
Keyword(s):  
Sexual Selection ◽  
Song Complexity ◽  
Two Factors

scholarly journals Environmental variability and acoustic signals: a multi-level approach in songbirds

2012 ◽  
Vol 8 (6) ◽  
pp. 928-931 ◽  
Author(s):  
Iliana Medina ◽  
Clinton D. Francis
Keyword(s):  
Sexual Selection ◽  
Environmental Variability ◽  
Extensive Study ◽  
Short Term ◽  
Intraindividual Variation ◽  
Habitat Features ◽  
Acoustic Adaptation ◽  
Song Complexity ◽  
Song Variation ◽  
Precipitation Seasonality

Among songbirds, growing evidence suggests that acoustic adaptation of song traits occurs in response to habitat features. Despite extensive study, most research supporting acoustic adaptation has only considered acoustic traits averaged for species or populations, overlooking intraindividual variation of song traits, which may facilitate effective communication in heterogeneous and variable environments. Fewer studies have explicitly incorporated sexual selection, which, if strong, may favour variation across environments. Here, we evaluate the prevalence of acoustic adaptation among 44 species of songbirds by determining how environmental variability and sexual selection intensity are associated with song variability (intraindividual and intraspecific) and short-term song complexity. We show that variability in precipitation can explain short-term song complexity among taxonomically diverse songbirds, and that precipitation seasonality and the intensity of sexual selection are related to intraindividual song variation. Our results link song complexity to environmental variability, something previously found for mockingbirds (Family Mimidae). Perhaps more importantly, our results illustrate that individual variation in song traits may be shaped by both environmental variability and strength of sexual selection.

scholarly journals Sexual selection, body mass and molecular evolution interact to predict diversification in birds

2019 ◽  
Vol 286 (1899) ◽  
pp. 20190172 ◽  
Author(s):  
Maider Iglesias-Carrasco ◽  
Michael D. Jennions ◽  
Simon Y. W. Ho ◽  
David A. Duchêne
Keyword(s):  
Sexual Selection ◽  
Molecular Evolution ◽  
Body Mass ◽  
Genome Data ◽  
Rate Of Molecular Evolution ◽  
Two Factors ◽  
Evolutionary Radiations ◽  
Selection For ◽  
High Degree ◽  
Lineage Diversification

Sexual selection is a powerful agent of evolution, driving microevolutionary changes in the genome and macroevolutionary rates of lineage diversification. The mechanisms by which sexual selection might influence macroevolution remain poorly understood. For example, sexual selection might drive positive selection for key adaptations that facilitate diversification. Furthermore, sexual selection might be a general driver of molecular evolutionary rate. We lay out some of the potential mechanisms that create a link between sexual selection and diversification, based on causal effects on other life-history traits such as body mass and the rate of molecular evolution. Birds are ideally suited for testing the importance of these relationships because of their diverse reproductive systems and the multiple evolutionary radiations that have produced their astounding modern diversity. We show that sexual selection (measured as the degree of polygyny) interacts with the rate of molecular evolution and with body mass to predict species richness at the genus level. A high degree of polygyny and rapid molecular evolution are positively associated with the net rate of diversification, with the two factors being especially important for explaining diversification in large-bodied taxa. Our findings further suggest that mutation rates underpin some of the macroevolutionary effects of sexual selection. We synthesize the existing theory on sexual selection as a force for diversity and propose avenues for exploring this association using genome data.

Slow Down You’re Moving Too Fast

2015 ◽  
Vol 27 (2) ◽  
pp. 53-63 ◽  
Author(s):  
Annie Lang ◽  
Nancy Schwartz ◽  
Sharon Mayell
Keyword(s):  
Older Adults ◽  
Cognitive Aging ◽  
Attention And Memory ◽  
Younger Adults ◽  
Media Messages ◽  
Two Factors ◽  
The Difference

The study reported here compared how younger and older adults processed the same set of media messages which were selected to vary on two factors, arousing content and valence. Results showed that older and younger adults had similar arousal responses but different patterns of attention and memory. Older adults paid more attention to all messages than did younger adults. However, this attention did not translate into greater memory. Older and younger adults had similar levels of memory for slow-paced messages, but younger adults outperformed older adults significantly as pacing increased, and the difference was larger for arousing compared with calm messages. The differences found are in line with predictions made based on the cognitive-aging literature.

Effects of an Anxiety-Specific Psychometric Factor on Fear Conditioning and Fear Generalization

2017 ◽  
Vol 225 (3) ◽  
pp. 200-213 ◽  
Author(s):  
Christian Baumann ◽  
Miriam A. Schiele ◽  
Martin J. Herrmann ◽  
Tina B. Lonsdorf ◽  
Peter Zwanzger ◽  
...  
Keyword(s):  
Risk Factor ◽  
Anxiety Disorders ◽  
Fear Conditioning ◽  
Longitudinal Design ◽  
Principal Component ◽  
Anxiety And Depression ◽  
Specific Factor ◽  
High Anxious ◽  
Two Factors ◽  
Fear Generalization

Abstract. Conditioning and generalization of fear are assumed to play central roles in the pathogenesis of anxiety disorders. Here we investigate the influence of a psychometric anxiety-specific factor on these two processes, thus try to identify a potential risk factor for the development of anxiety disorders. To this end, 126 healthy participants were examined with questionnaires assessing symptoms of anxiety and depression and with a fear conditioning and generalization paradigm. A principal component analysis of the questionnaire data identified two factors representing the constructs anxiety and depression. Variations in fear conditioning and fear generalization were solely associated with the anxiety factor characterized by anxiety sensitivity and agoraphobic cognitions; high-anxious individuals exhibited stronger fear responses (arousal) during conditioning and stronger generalization effects for valence and UCS-expectancy ratings. Thus, the revealed psychometric factor “anxiety” was associated with enhanced fear generalization, an assumed risk factor for anxiety disorders. These results ask for replication with a longitudinal design allowing to examine their predictive validity.

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