scholarly journals Selection on parental performance opposes selection for larger body mass in a wild population of blue tits

Evolution ◽  
2017 ◽  
Vol 71 (3) ◽  
pp. 716-732 ◽  
Author(s):  
Caroline E. Thomson ◽  
Florian Bayer ◽  
Nicholas Crouch ◽  
Samantha Farrell ◽  
Elizabeth Heap ◽  
...  
Evolution ◽  
2018 ◽  
Vol 73 (1) ◽  
pp. 28-41 ◽  
Author(s):  
Caroline E. Thomson ◽  
Jarrod D. Hadfield
Keyword(s):  

2009 ◽  
Vol 22 (9) ◽  
pp. 1867-1874 ◽  
Author(s):  
J.-Å. NILSSON ◽  
M. ÅKESSON ◽  
J. F. NILSSON

2014 ◽  
Author(s):  
Peter G Tickle ◽  
Heather Paxton ◽  
Jeffery W Rankin ◽  
John R. Hutchinson ◽  
Jonathan R Codd

Genetic selection for improved meat yields, digestive efficiency and growth rates have transformed the biology of broiler chickens. Modern birds undergo a 50-fold multiplication in body mass in just six weeks, from hatching to slaughter weight. However, this selection for rapid growth and improvements in broiler productivity is also widely thought to be associated with increased welfare problems as many birds suffer from leg, circulatory and respiratory diseases. To understand growth-related changes in musculoskeletal and organ morphology and respiratory skeletal development over the standard six-week rearing period, we present data from post-hatch cadaveric commercial broiler chickens aged 0, 2, 4 and 6 weeks. The heart, lungs and intestines decreased in size for hatch to slaughter weight when considered as a proportion of body mass. Proportional liver size increased in the two weeks after hatch but decreased between 2 and 6 weeks. Breast muscle mass on the other hand displayed strong positive allometry, increasing in mass faster than the increase in body mass. Contrastingly, less rapid isometric growth was found in the external oblique muscle, a major respiratory muscle that moves the sternum dorsally during expiration. Considered together with the relatively slow ossification of elements of the respiratory skeleton, it seems that rapid growth of the breast muscles might compromise the efficacy of the respiratory apparatus. Furthermore, the relative reduction in size of the major organs indicates that selective breeding in meat-producing birds has unintended consequences that may bias these birds toward compromised welfare and could limit further improvements in meat-production and feed efficiency.


The Auk ◽  
1985 ◽  
Vol 102 (2) ◽  
pp. 323-333 ◽  
Author(s):  
Robert E. Ricklefs ◽  
Henry L. Marks

2006 ◽  
Vol 63 (7) ◽  
pp. 1234-1247 ◽  
Author(s):  
Kjetil Hindar ◽  
Ian A. Fleming ◽  
Philip McGinnity ◽  
Ola Diserud

Abstract Cultured salmonids are released or escape into the wild in large numbers and may make up significant proportions of wild salmonid populations in fresh- and saltwater, causing considerable concern for the fitness and productivity of these populations. This paper focuses on the effects of escaped farmed Atlantic salmon (Salmo salar) on wild salmon. Farmed salmon have been under artificial selection for growth and other economically important traits for 30 years and are genetically different in their origin at the molecular and quantitative genetic levels. Escaped farmed salmon spawn in the wild with limited success. Their offspring outgrow those of wild origin but suffer higher mortality. Whole-river experiments in Ireland and Norway have shown that the lifetime success of farmed salmon is reduced relative to wild salmon. Based on data from these experiments, we model the future of wild salmon populations experiencing invasions of escaped farmed salmon. Simulations with a fixed intrusion rate of 20% escaped farmed salmon at spawning suggest that substantial changes take place in wild salmon populations within ten salmon generations (∼40 years). Low-invasion scenarios suggest that farmed offspring are unlikely to become established in the population, whereas high-invasion scenarios suggest that populations are eventually mixtures of hybrid and farmed descendants. Recovery of the wild population is not likely under all circumstances, even after many decades without further intrusion. Managers of wild salmon will have difficulty in obtaining broodstock of the original wild population after a few generations of high intrusion. We conclude that further measures to reduce escapes of farmed salmon and their spawning in wild populations are urgently needed.


2021 ◽  
Author(s):  
Szymon Marian Drobniak ◽  
Magdalena Zagalska-Neubauer ◽  
Mariusz Cichoń

Microbiome constitutes and important axis of individual variation, affecting physiology and body condition via a number of pathways. Consequently, microbiome may be involved in ecological feedbacks, manifesting themselves as associations between microbiome characteristics and ecological factors experienced by individuals. In this study we report on the diversity and habitat dependence of microbiomes in a wild population of blue tits (Cyanistes caeruleus). Our results indicate, that birds nesting in different habitats (full-grown deciduous forest vs. open forest hay meadows) have microbiomes of different composition and microbial diversity, with birds nesting in dens forests having higher diversity of microbial species.


2014 ◽  
Author(s):  
Peter G Tickle ◽  
Heather Paxton ◽  
Jeffery W Rankin ◽  
John R. Hutchinson ◽  
Jonathan R Codd

Genetic selection for improved meat yields, digestive efficiency and growth rates have transformed the biology of broiler chickens. Modern birds undergo a 50-fold multiplication in body mass in just six weeks, from hatching to slaughter weight. However, this selection for rapid growth and improvements in broiler productivity is also widely thought to be associated with increased welfare problems as many birds suffer from leg, circulatory and respiratory diseases. To understand growth-related changes in musculoskeletal and organ morphology and respiratory skeletal development over the standard six-week rearing period, we present data from post-hatch cadaveric commercial broiler chickens aged 0, 2, 4 and 6 weeks. The heart, lungs and intestines decreased in size for hatch to slaughter weight when considered as a proportion of body mass. Proportional liver size increased in the two weeks after hatch but decreased between 2 and 6 weeks. Breast muscle mass on the other hand displayed strong positive allometry, increasing in mass faster than the increase in body mass. Contrastingly, less rapid isometric growth was found in the external oblique muscle, a major respiratory muscle that moves the sternum dorsally during expiration. Considered together with the relatively slow ossification of elements of the respiratory skeleton, it seems that rapid growth of the breast muscles might compromise the efficacy of the respiratory apparatus. Furthermore, the relative reduction in size of the major organs indicates that selective breeding in meat-producing birds has unintended consequences that may bias these birds toward compromised welfare and could limit further improvements in meat-production and feed efficiency.


PLoS ONE ◽  
2006 ◽  
Vol 1 (1) ◽  
pp. e72 ◽  
Author(s):  
Staffan Bensch ◽  
Henrik Andrén ◽  
Bengt Hansson ◽  
Hans Chr. Pedersen ◽  
Håkan Sand ◽  
...  

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