use range between two columns to determine and reduce to non-redundant representation

[webdev]

I am very very new to perl and am not even sure if awk is what I should be using instead. Hopefully someone out there can help me put together a script for this problem. Here is some sample data (it is tab delineated in my file): 20 scaffold189_125 13634 13384 13884 D aga-miR-1890_MI -2 1.28e-01...