scholarly journals TWO-WAY SELECTION FOR BODY SIZE IN RATS, WITH OBSERVATIONS ON SIMULTANEOUS CHANGES IN COAT COLOR PATTERN AND HOOD SIZE

Genetics ◽  
1960 ◽  
Vol 45 (4) ◽  
pp. 467-483
Author(s):  
Lois M Zucker
Keyword(s):  
Body Size ◽  
Coat Color ◽  
Color Pattern ◽  
Selection For

scholarly journals Analysis of ROH patterns in the Noriker horse breed reveals signatures of selection for coat color and body size

2019 ◽  
Vol 50 (4) ◽  
pp. 334-346 ◽  
Author(s):  
G. Grilz‐Seger ◽  
T. Druml ◽  
M. Neuditschko ◽  
M. Mesarič ◽  
M. Cotman ◽  
...  
Keyword(s):  
Body Size ◽  
Coat Color ◽  
Horse Breed ◽  
Signatures Of Selection ◽  
Selection For

scholarly journals Atmospheric Hypoxia Limits Selection for Large Body Size in Insects

PLoS ONE ◽  
2009 ◽  
Vol 4 (1) ◽  
pp. e3876 ◽  
Author(s):  
C. Jaco Klok ◽  
Jon F. Harrison
Keyword(s):  
Body Size ◽  
Large Body ◽  
Large Body Size ◽  
Selection For

scholarly journals Continued artificial selection for running endurance in rats is associated with improved lung function

2009 ◽  
Vol 106 (6) ◽  
pp. 1810-1818 ◽  
Author(s):  
Scott D. Kirkton ◽  
Richard A. Howlett ◽  
Norberto C. Gonzalez ◽  
Patrick G. Giuliano ◽  
Steven L. Britton ◽  
...  
Keyword(s):  
Body Size ◽  
Lung Volume ◽  
Maximal Oxygen Consumption ◽  
Endurance Capacity ◽  
Endurance Running ◽  
Body Frame ◽  
Cardiopulmonary Function ◽  
Muscle Adaptations ◽  
Selection For ◽  
Seven Generations

Previous studies found that selection for endurance running in untrained rats produced distinct high (HCR) and low (LCR) capacity runners. Furthermore, despite weighing 14% less, 7th generation HCR rats achieved the same absolute maximal oxygen consumption (V̇o2max) as LCR due to muscle adaptations that improved oxygen extraction and use. However, there were no differences in cardiopulmonary function after seven generations of selection. If selection for increased endurance capacity continued, we hypothesized that due to the serial nature of oxygen delivery enhanced cardiopulmonary function would be required. In the present study, generation 15 rats selected for high and low endurance running capacity showed differences in pulmonary function. HCR, now 25% lighter than LCR, reached a 12% higher absolute V̇o2max than LCR, P < 0.05 (49% higher V̇o2max/kg). Despite the 25% difference in body size, both lung volume (at 20 cmH2O airway pressure) and exercise diffusing capacity were similar in HCR and LCR. Lung volume of LCR lay on published mammalian allometrical relationships while that of HCR lay above that line. Alveolar ventilation at V̇o2max was 30% higher, P < 0.05 (78% higher, per kg), arterial Pco2 was 4.5 mmHg (17%) lower, P < 0.05, while total pulmonary vascular resistance was (insignificantly) 5% lower (30% lower, per kg) in HCR. The smaller mass of HCR animals was due mostly to a smaller body frame rather than to a lower fat mass. These findings show that by generation 15, lung size in smaller HCR rats is not reduced in concert with their smaller body size, but has remained similar to that of LCR, supporting the hypothesis that continued selection for increased endurance capacity requires relatively larger lungs, supporting greater ventilation, gas exchange, and pulmonary vascular conductance.

Metacarpals and manual phalanges

2020 ◽  
pp. 106-143
Author(s):  
Tracy L. Kivell ◽  
Kelly R. Ostrofsky ◽  
Brian G. Richmond ◽  
Michelle S.M. Drapeau
Keyword(s):  
Body Size ◽  
South African ◽  
Index Finger ◽  
External Morphology ◽  
Australopithecus Africanus ◽  
Fossil Evidence ◽  
Frequent Use ◽  
Selection For ◽  
Locomotor Behaviors ◽  
Fossil Hominin

This chapter presents description and analysis of the metacarpals and manual phalanges from Sterkfontein. Although the morphology is generally similar across the sample where there are duplicates of the same element, there are differences in size that are quite remarkable within the context of all South African hominins. Some very large specimens suggest the presence of individuals at Sterkfontein with much larger hands, and presumably larger body size, at Sterkfontein than those of A. sediba MH2, H. naledi and the Swartkrans hominins. Australopithecus africanus had human-like proportions, but this may be plesiomorphic within the hominoid clade. The potentially less mobile trapezium-Mc1 joint, absence of a fully developed palmar pulp on the distal thumb, more limited pronation of the index finger, and potentially more wedge-shaped trapezoid inferred from the preserved external morphology, is consistent with lower manipulative loading of the thumb than is typical of later Homo. As for other forelimb elements, moderately curved manual phalanges suggests a greater reliance on forelimb-dominated locomotor behaviors and perhaps selection for more frequent use of an arboreal environment in A. africanus than is found in A. afarensis. Thus, within this broader context, the Sterkfontein fossil hominin remains are not unusual. The Sterkfontein hand fossils suggest an overall manipulative and locomotor loading regime that was more similar to that of other South African australopiths and distinct from that of later Homo, but more refined functional interpretations require additional fossil evidence, particularly from associated hand skeletons

scholarly journals Selection for small body size favours contrasting sex-specific life histories, boldness and feeding in medaka, Oryzias latipes

2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Beatriz Diaz Pauli ◽  
Sarah Garric ◽  
Charlotte Evangelista ◽  
L. Asbjørn Vøllestad ◽  
Eric Edeline
Keyword(s):  
Body Size ◽  
Life Histories ◽  
Small Body ◽  
Oryzias Latipes ◽  
Small Body Size ◽  
Selection For

Variation in the Coat-Color Pattern of Hereford Cattle

1975 ◽  
Vol 66 (3) ◽  
pp. 147-150 ◽  
Author(s):  
D. E. FRANKE ◽  
W. C. BURNS ◽  
M. KOGER
Keyword(s):  
Coat Color ◽  
Color Pattern ◽  
Hereford Cattle

scholarly journals Selection for reduced fear in red junglefowl changes brain composition and affects fear memory

2020 ◽  
Vol 7 (8) ◽  
pp. 200628
Author(s):  
Rebecca Katajamaa ◽  
Per Jensen
Keyword(s):  
Body Size ◽  
Brain Size ◽  
Prior Experience ◽  
Fear Memory ◽  
Brain Regions ◽  
Preference Learning ◽  
Response To Selection ◽  
Red Junglefowl ◽  
Selection For ◽  
Region Size

Brain size reduction is a common trait in domesticated species when compared to wild conspecifics. This reduction can happen through changes in individual brain regions as a response to selection on specific behaviours. We selected red junglefowl for 10 generations for diverging levels of fear towards humans and measured brain size and composition as well as habituation learning and conditioned place preference learning in young chicks. Brain size relative to body size as well as brainstem region size relative to whole brain size were significantly smaller in chicks selected for low fear of humans compared to chicks selected for high fear of humans. However, when including allometric effects in the model, these differences disappear but a tendency towards larger cerebra in low-fear chickens remains. Low-fear line chicks habituated more effectively to a fearful stimulus with prior experience of that same stimulus, whereas high-fear line chicks with previous experience of the stimulus had a response similar to naive chicks. The phenotypical changes are in line with previously described effects of domestication.

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