▁cr ust al ▁thin ning ▁theory , ▁block ▁fault ing ▁and ▁a ▁r idge ▁formed ▁in ▁the ▁region ▁ow ing ▁to ▁thin ning ▁and ▁as ser ts ▁that ▁development ▁of ▁this ▁r idge ▁augment ed ▁the ▁cor al ▁growth ▁in ▁the ▁area ▁and ▁in ▁turn ▁cor al ▁cover ▁acted ▁as ▁a ▁' s and ▁tra pper '. ▁ ▁The ▁tom bol o ▁model ▁aff ir ms ▁a ▁constant ▁sed iment ▁source ▁and ▁a ▁high ▁un id irection al ▁or ▁bi - direction al ▁( mon so onal ) ▁long sh ore ▁current . ▁One ▁study ▁tent atively ▁con cludes ▁that ▁there ▁is ▁ins u fficient ▁evidence ▁to ▁indicate ▁e ust atic ▁emer gence ▁and ▁that ▁the ▁raised ▁re ef ▁in ▁southern ▁India ▁probably ▁results ▁from ▁a ▁local ▁u pl ift . ▁Other ▁studies ▁also ▁conclude ▁that ▁during ▁periods ▁of ▁lower ed ▁sea ▁level ▁over ▁the ▁last ▁ 1 0 0 , 0 0 0 ▁years , ▁Adam ' s ▁Bridge ▁has ▁provided ▁an ▁inter mitt ent ▁land ▁connection ▁between ▁India ▁and ▁Sri ▁L anka , ▁which ▁according ▁to ▁famous ▁orn ith olog ists ▁Sid ney ▁D illon ▁Ri ple y ▁and ▁Bruce ▁Be eh ler ▁supports ▁the ▁vic ar iance ▁model ▁for ▁spe ci ation ▁in ▁some ▁birds ▁of ▁the ▁Indian ▁Sub cont inent . ▁ ▁Age ▁The ▁studies ▁under ▁" Project ▁R ames war am " ▁of ▁the ▁Ge ological ▁Survey ▁of ▁India ▁( G SI ), ▁which ▁included ▁d ating ▁of ▁cor als , ▁indicate ▁R ames war am ▁Island ▁evol