Tajima's D value interpretation

Question

[rohan.pat.131191]

For my sequences I got Tajima's D value as -0.94880 and P > 0.10. I was wondering if I could use this results to claim that the test of neutrality is negative and the molecule under consideration is under selection pressure?

Answer 1

[tlorin]

I can't answer with more detail to your question, I'm sorry, but just FYI this is an excellent video on this topic :)

Answer 2

[Giovanni M Dall'Olio]

A negative Tajima's D value is usually interpreted as purifying selection, or as a signature of a recent population expansion.

You didn't explain how you calculated the p-value, so it is difficult to interpret it. It seems that it is higher than 0.10, so not significant. You should plot the distribution of Tajima's D on the rest of the genome (or at least the same chromosome), and see where your value falls.

[jigarnt]

I have calculated Tajima's d from Pairwise data and no of segregating sites. How to Normalize "d" valus into "D" manually as I have calculated my Tajima's d from character data and not sequence data.

[gusa_10]

Here we are having a conflict. While Tajima'D and Fu's are significant and negative, our BSP indicates a no recent event of population expansion but constant size. We used D-loop and ~1000 sample size for a single population. Do you know why this conflict ocurrs?

Answer 3

[simar-coasab]

what 'Tajima's D (NonSyn/Syn) ratio' tells?

Answer 4

[gusa_10]

Here we are having a conflict. While Tajima'D and Fu's are significant and negative, our BSP indicates a no recent event of population expansion but constant size. We used D-loop and ~1000 sample size for a single population. Do you know why this conflict ocurrs?