Breeding Systems and Social Organisation

The Skuas ◽  
2014 ◽  
Keyword(s):  
Social Organisation ◽  
Breeding Systems

scholarly journals Testis size and spermatogenesis of tsessebes from Nylsvley Nature Reserve, Transvaal

Koedoe ◽  
1993 ◽  
Vol 36 (1) ◽  
Author(s):  
B.L. Penzhorn ◽  
N.J. Van der Merwe
Keyword(s):  
Nature Reserve ◽  
Social Organisation ◽  
Breeding Systems ◽  
Testis Size ◽  
Mating Season ◽  
Class D ◽  
Testis Mass

Testis mass of adult tsessebes (mean 45,3 g) and relative testis size (0,56) were consistent with the Class D social organisation of tsessebes. In singleale breeding systems, testes are relatively small. Spermatogenesis reached a peak in January, prior to the onset of the mating season.

Analysis of the effectiveness of Landrace families pigs breeding systems

2017 ◽  
Vol 1 (68) ◽  
pp. 153-157
Author(s):  
Natalia Lyashenko ◽  
◽  
Alexander Jarmoc ◽  
Maria Galicheva ◽  
Irina Tletseruk ◽  
...  
Keyword(s):  
Breeding Systems

scholarly journals DNA Polymorphism in Lycopersicon and Crossing-Over per Physical Length

Genetics ◽  
1998 ◽  
Vol 150 (4) ◽  
pp. 1585-1593 ◽  
Author(s):  
Wolfgang Stephan ◽  
Charles H Langley
Keyword(s):  
Dna Sequence ◽  
Dna Polymorphism ◽  
Sequence Polymorphism ◽  
Breeding Systems ◽  
Crossing Over ◽  
Physical Length ◽  
Interspecific Divergence ◽  
Dna Sequence Polymorphism ◽  
Outcrossing Species ◽  
Genomic Regions

Abstract Surveys in Drosophila have consistently found reduced levels of DNA sequence polymorphism in genomic regions experiencing low crossing-over per physical length, while these same regions exhibit normal amounts of interspecific divergence. Here we show that for 36 loci across the genomes of eight Lycopersicon species, naturally occurring DNA polymorphism (scaled by locus-specific divergence between species) is positively correlated with the density of crossing-over per physical length. Large between-species differences in the amount of DNA sequence polymorphism reflect breeding systems: selfing species show much less within-species polymorphism than outcrossing species. The strongest association of expected heterozygosity with crossing-over is found in species with intermediate levels of average nucleotide diversity. All of these observations appear to be in qualitative agreement with the hitchhiking effects caused by the fixation of advantageous mutations and/or “background selection” against deleterious mutations.

Post-work society as an oxymoron: Why we cannot, and should not, wish work away

2021 ◽  
pp. 136843102110121
Author(s):  
Jean-Philippe Deranty
Keyword(s):  
Social Organisation ◽  
Alternative Response ◽  
The World ◽  
Work And Employment

In recent years, theorists have contended that we should move to a mode of social organisation where work and the values attached to it are no longer central, a ‘post-work society’. For these theorists, the modern ideology of work is intrinsically unjust, even irrational and no longer suited to the challenges of our time. The article presents an alternative response to the problems of work and employment. Rather than moving to a ‘post-work’ society, the article argues that we should transform the world of work, precisely by keeping in view why working is important to individuals and the community. In fact, it is not realistic to believe that human societies could ever do without work. Because human societies are by necessity work societies, and work, if organised correctly, entails many goods, we cannot really, and we should not, wish work away.

scholarly journals The role of historical factors and natural selection in the evolution of breeding systems of Oxalis alpina in the Sonoran desert ‘Sky Islands’

2010 ◽  
Vol 23 (10) ◽  
pp. 2163-2175 ◽  
Author(s):  
J. PÉREZ-ALQUICIRA ◽  
F. E. MOLINA-FREANER ◽  
D. PIÑERO ◽  
S. G. WELLER ◽  
E. MARTÍNEZ-MEYER ◽  
...  
Keyword(s):  
Natural Selection ◽  
Sonoran Desert ◽  
Breeding Systems ◽  
Sky Islands ◽  
Historical Factors

A simulation study of open nucleus and closed nucleus breeding systems in a sheep population

1995 ◽  
Vol 60 (1) ◽  
pp. 117-124 ◽  
Author(s):  
J. A. Roden
Keyword(s):  
Genetic Gain ◽  
Live Weight ◽  
Breeding Systems ◽  
Breeding Value ◽  
Linear Unbiased Prediction ◽  
Sheep Population ◽  
Best Linear Unbiased ◽  
Nucleus Breeding ◽  
Open Nucleus ◽  
Selection Of

AbstractStochastic simulation was used to compare the results of alternative breeding systems in a sheep population divided into 10 flocks of 120 ewes. The breeding systems compared were selection within closed flocks (CF), a closed nucleus system (CNS), an open nucleus system (ONS) and open nucleus systems with the selection of nucleus replacements being restricted to either nucleus born males (ONSRm) or nucleus born females (ONSRf). Selection was for a best linear unbiased prediction of breeding value for lamb live weight which had a heritability of 0·17. The open nucleus breeding systems (ONS, ONSRm, ONSRf) resulted in higher rates of genetic gain, more predictable selection responses and lower rates of inbreeding than either the closed nucleus system (CNS) or selection within closed flocks (CF). Initial genetic differences between flocks resulted in higher rates of genetic gain in the nucleus breeding systems due to the use of between flock genetic variance. In the ONS system up to 25% of nucleus sires and approximately 50% of nucleus dams were born in base flocks. Nevertheless if selection of either nucleus sires or dams was restricted to nucleus born animals there was very little change in genetic gain or rate of inbreeding.

On Social Organisation and Social Personality: Selected Papers.

Man ◽  
1967 ◽  
Vol 2 (3) ◽  
pp. 471
Author(s):  
Duncan Mitchell ◽  
W. I. Thomas
Keyword(s):  
Social Organisation
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