[R] adjusted p value, fdr

[Ana Marija]

Hello,

I have a data set which has 15568 entries

I am trying to calculate adjusted p values using p value via:

head(x1g)

                                                   t      P.Value
      adj.P.Val          B       fdr
3TXADqtSkhV1IXRHlg  4.468671 3.072189e-05 0.4782784  1.5253151 0.4782784
34lG83aZ6.WLFnge6s  4.217037 7.518696e-05 0.5852553  0.8660534 0.5852553
oS67lguv5HpU4i6Pvg -3.939182 1.959413e-04 0.9994637  0.1600655 0.9994637
Qpc2sX7gp.W5E2rRS4  3.732914 3.900822e-04 0.9994637 -0.3471331 0.9994637
NqsVOy_yos30cOQRSE -3.673551 4.737810e-04 0.9994637 -0.4902001 0.9994637
B3SDpegGjpdxnvU0S0 -3.665765 4.859528e-04 0.9994637 -0.5088638 0.9994637

x1g$fdr=p.adjust(x1g$P.Value,method="BH")

the fdr values seem unusually high

if I just do it for the first few p values from my x1g data frame:
>pval=c(3.072189e-05,7.518696e-05,1.959413e-04,3.900822e-04)
> p.adjust(pval,method="BH")
[1] 0.0001228876 0.0001503739 0.0002612551 0.0003900822

Can someone please explain what might be the issue.

Thanks
Ana