Population Genetics of Mexican Drosophila. V. A High Rate of Multiple Insemination in a Natural Population of Drosophila pseudoobscura

1980 ◽  
Vol 116 (4) ◽  
pp. 493-503 ◽  
Author(s):  
L. Levine ◽  
M. Asmussen ◽  
O. Olvera ◽  
J. R. Powell ◽  
M. E. de la Rosa ◽  
...  
Keyword(s):  
Population Genetics ◽  
Natural Population ◽  
High Rate ◽  
Drosophila Pseudoobscura

The ecology of a natural population of the Queensland fruit fly, Dacus tryoni. I. The parameters of the pupal and adult populations during a single season

1967 ◽  
Vol 15 (2) ◽  
pp. 303 ◽  
Author(s):  
MA Bateman ◽  
FJ Sonleitner
Keyword(s):  
Young Adults ◽  
Natural Population ◽  
Adult Population ◽  
Adult Emergence ◽  
Fruit Fly ◽  
Fruit Trees ◽  
High Rate ◽  
Larval Food ◽  
Gravid Females ◽  
Pupal Mortality

The ecology of a natural population of Dacus tryoni is being studied at an orchard near Sydney, N.S.W. Changes in numbers observed during a single year are described and discussed. Estimates of pupal numbers were based on the weekly total pupal production of a random sample of the fruit trees in the orchard. Parameters of the adult population were measured by means of mark-recapture sampling and analysed by means of three mathematical models. Discrepancies between some of the estimates of numbers given by these models are explained by extensive adult emergence at those times, and the lower survival factors of the young adults. Evidence for the random sampling of adults is presented. The decline of the population towards the end of the season was brought about mainly by (1) high pupal mortality, (2) cessation of pupal production due to diminution and disappearance of larval food, (3) a marked decline in the number of gravid females, apparently in response to diminishing oviposition sites, and (4) a high rate of loss of young adults, presumably by emigration. There was no evidence of overcrowding.

POPULATION GENETICS OF MEXICAN DROSOPHILA VI. CYTOGENETIC ASPECTS OF THE INVERSION POLYMORPHISM IN DROSOPHILA PSEUDOOBSCURA

Evolution ◽  
1979 ◽  
Vol 33 (1Part2) ◽  
pp. 381-395 ◽  
Author(s):  
O. Olvera ◽  
J. R. Powell ◽  
M. E. de la Rosa ◽  
V. M. Salceda ◽  
M. I. Gaso ◽  
...  
Keyword(s):  
Population Genetics ◽  
Inversion Polymorphism ◽  
Drosophila Pseudoobscura

Dobzhansky and Dreyfus’s Group: The Introduction of Natural Population Genetics Studies in Brazil (1943–1960)

2020 ◽  
Vol 28 (2) ◽  
pp. 244-276
Author(s):  
José Franco Monte Sião ◽  
Lilian Al-Chueyr Pereira Martins
Keyword(s):  
Population Genetics ◽  
Natural Population ◽  
Genetic Research ◽  
The Third ◽  
Theodosius Dobzhansky ◽  
The Subject ◽  
Important Center ◽  
The University ◽  
The Impact ◽  
And Linguistics

An important center in which genetic research started and was carried out in Brazil during the 20th century was situated at the Faculty of Philosophy, Sciences and Linguistics of the University of São Paulo, led by André Dreyfus (1897–1952). Beginning in 1943, the Ukrainian geneticist Theodosius Dobzhansky (1900–1975) visited Dreyfus’s group four times. This paper evaluates the impact of Dobzhansky’s visits on the studies of genetics and evolution developed by the members of Dreyfus’s group during the 1940s and the 1950s. The study leads to the conclusion that Dobzhansky’s visits had an impact, not only in quantitative terms (the number of individual and joint publications), but also in qualitative terms. However, we also detect a decrease in the number of individual and joint publications related to the subject of the project during certain periods. The adoption of new experimental organisms by some members of the group; the involvement with subjects not related to the initial project, such as botany; Dobzhansky’s and his wife’s health problems during the third visit; and scientific disagreements between Dobzhansky and Brazilian researchers may have contributed to the decrease in publications.

scholarly journals Temporal stability of P–M cytotype polymorphism in a natural population of Drosophila melanogaster

1987 ◽  
Vol 50 (2) ◽  
pp. 99-103 ◽  
Author(s):  
Hassan Izaabel ◽  
Stephane Ronsseray ◽  
Dominique Anxolabéhère
Keyword(s):  
Drosophila Melanogaster ◽  
Transposable Elements ◽  
Natural Population ◽  
North Africa ◽  
Temporal Stability ◽  
Genetic Load ◽  
Hybrid Dysgenesis ◽  
P Element ◽  
High Rate ◽  
Genetic Abnormalities

SummaryThe P–M system of hybrid dysgenesis in Drosophila melanogaster is a syndrome of genetic abnormalities which appears in the progeny of crosses between strains different with regard to their possession of ‘P’ transposable elements. Cytotype is an extrachromosomal property which regulates the mobility of the P element. We report here data showing that a cytotype polymorphism previously observed in a natural population from North-Africa is stable over a period of 5 years. A potentially high rate of mutation is associated with this cytotype polymorphism. Explanations of the appearance of a cytotype polymorphism are proposed and the consequences for the genetic load induced by transposable elements are discussed.

Analisi popolazionistica dell'etnia Valdostana attraverso il fenomeno gemellare

1961 ◽  
Vol 10 (3) ◽  
pp. 270-276
Author(s):  
L. Gedda ◽  
G. Brenci ◽  
S. Bérard-Magistretti ◽  
F. Magistretti
Keyword(s):  
Population Genetics ◽  
High Rate ◽  
Twin Method

SUMMARYThe Authors have studied, from the standpoint of population genetics, twins born in the Aosta Valley from 1910 to 1957. This material, consisting in 980 pairs, has been examined from the standpoint of the frequency ot twin deliveries (Gemelliparity Index), of monozygosity (Monozygosity Index), and of patronymic (Patronymic Index). The Authors show that the region may be divided in geo-demographical departments, 6 of which may be considered « isolates » with a high rate of inbreeding. Moreover, the usefulness of the twin-method in population genetics is demonstrated.

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