Biomedical subjects

F A Lints

Publications and source records attributed to F A Lints.

58 records · Page 4Linked to original sources

PubMedDate not supplied

Geographic variations of life history strategies in Drosophila melanogaster. I. Analysis of wild-caught populations.

Life history traits--hatchability, developmental time, longevity, and egg production--of five freshly caught European populations of Drosophila melanogaster were measured under homogeneous laboratory conditions. No significant phenotypic correlations between early and late fitness could be found for the five populations at the within-population level. At the between-population level, no consistent indication of any significant genetic correlation, either positive or negative, was detected for the same traits. These results are not in agreement either with the predictions of the antagonistic pleiotropy hypothesis proposed by Williams, nor with the opposite hypothesis suggested by Lints. The results suggest that natural populations of Drosophila melanogaster are genetically different for at least some life history traits measured in the laboratory as soon as possible after capture.

Aging↗

PubMedDate not supplied

Geographic variations of life history strategies in Drosophila melanogaster. II. Analysis of laboratory-adapted populations.

Life history traits--hatchability, longevity, and egg production--of five wild-caught populations of Drosophila melanogaster were measured after these populations had been reared in constant laboratory conditions during a 4-year period. The results were analyzed together with those that had been obtained with the same populations just after capture. They are probably the first convincing results that reveal the existence of genetic variability for some life history traits measured in the laboratory. Besides, no significant phenotypic correlations, either positive or negative, between early and late components of fitness were found. Finally, the five populations showed different patterns of genetic correlation between early and late fitness traits. One of the populations showed a negative correlation, another showed a positive correlation, while the remaining three populations showed no correlation at all. This was equally observed at the within- and between-population levels. That result suggests that both the antagonistic pleiotropy hypothesis proposed by Williams and the concordant pleiotropy hypothesis suggested by Lints are not of general validity.

Adaptation, Biological↗

PubMedDate not supplied

Geographic variations of life history strategies in Drosophila melanogaster. III. New data.

A crucial assumption of evolutionary theories of aging is that age-specific differences of life history traits may have genetic causes. The present study focuses on the existence of such differences between eight freshly caught populations of Drosophila melanogaster. A highly significant differentiation of the populations is observed, yet it accounts for a relatively small part of the variance. It is also shown that large discrepancies may be found between the estimations of fitness based, on the one hand, on data for egg production and, on the other hand, on fertility data. This stresses the need for accurate measurements of fitness for the assessment of evolutionary theories. Finally, the results suggest that neither of the current evolutionary theories of aging is generally valid. Indeed, the age-specific differences that are found between the populations match either the antagonistic pleiotropy mechanism, or the concordant pleiotropy mechanism, or none of them.

Aging↗

PubMedDate not supplied

[Aging: genetic aspects].

Although most gerontologists, sometimes unconsciously, are ready to admit that ageing and life-span are genetically determined, it is a paradox to recognize that for the last 25 years most theories of ageing were stochastic in nature. The evidence in favour of such theories is reviewed and it is shown that they are most probably wrong. Yet the evidence in favour of a genetic basis for ageing and life-span is scarce and, until now, no definite proof of such a determinism has been provided.

Aging↗