Variability of Phototaxis 2

on Monday, September 21st, 2015 12:03 | by Isabelle Steymans

I redid the experiment where I took 8 groups of 80 flies and tested them 4 consecutive days, with the T-maze (Fig. 1) and decided to do a second control to see if the proportions are changing if I repeat the experiment several times the same day. Therefor I used again the Benzer-paradigm and did the same experiment like the one above, but instead of waiting 24 hours the flies were given only 3 hours to recover from the anaesthesia (Fig. 2).
As you can see doing the Experiment a second time has almost no effect, but the proportions change drastically the third time.

After that, I wanted to see if the proportion changed if only subgroups were tested. Therefor I tested again 8 groups with 80 flies. Then, I took tubes 5 and 4, and tubes 3-0 and tested them again after 24h hours of recovery (Fig. 3). Afterwards I did the same thing with 3 hours of recovery with a different group of flies (Fig.4).
In both cases there were almost no differences in the proportions between the experiment in which all flies were used and the experiment in which only the tubes 5 and 4 were used. Surprisingly, there is a big change in the proportions if only tubes 3-0 are tested.

Then I did the same experiment with the T-maze. After 24 hours of recovery I took the flies who went to the light and tested them again. I did the same thing with the ones who went to the dark and the elevator (Fig.5), but I had to test these two groups of flies together because otherwise there wouldn’t have been enough flies to reach the threshold of 40 flies. Like in the experiments above, the proportions when only flies that went to the light were tested were similar to the original proportions. However, in this case the flies who went to the dark and the elevator showed a small difference in the proportions.

Day1-4 T-maze

Fig. 1



1-4 3h exp.




Diff.Tubes Exp




Difftubes Exp.3h




DiffTubes T-maze24h


This is the new dataset with the final number of flies for the experiment above. (Fig. 6+7)
Additionally I did the corresponding boxplots to show the variability of the proportions (Fig. 8+9)

Exp.3 3h

Fig. 6

Exp.3 24h

Fig. 7

Exp.3 Boxplots 3h

Fig. 8

Exp.3 Boxplots 24h

Fig. 9

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Category: Individual choices in population paradigm, wing clipping

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