ISSN:
1573-3297
Schlagwort(e):
phototaxis
;
mating behavior
;
Drosophila
;
light intensity
Quelle:
Springer Online Journal Archives 1860-2000
Thema:
Biologie
,
Psychologie
Notizen:
Abstract Drosophila subobscura flies were selected for the ability to choose one of five light intensities (i.e., 30, 300, 1300, 3200, or 6500 lux), with the aid of an apparatus which enables the flies to choose freely. The original distribution of wild flies was as follows: about 60% repeatedly chose the space lighted by 6500 lux, about 30% 1300–3200 lux, and about 10% 30–300 lux. By mating the flies within each of the three categories for 19 generations, their proportion increased from 8 to 30% at 30–300 lux, from 32 to 55% at 1300–3200 lux, and from 60 to 78% at 6500 lux. The selective response was greatest at the beginning of the selection, and declined later. Using micronized dusts to mark the flies, it was determined that on the average about 33% of the flies chose the same light intensity in both of two 24-h runs, and about 31% more chose for the second time one of the neighboring light intensities. These experiments suggest that phototactic response is a relative property, so that a fly can be “photopositive” or “photonegative” to a dimmer light (including complete darkness) and to a light of much higher intensity.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1007/BF01074161
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