( ( Geological evidence ) ( ( shows ( that ( ( ice-albedo feedback ) ( ( ( caused ( sea ( ice advance ) ) ) to ) ( near ( ( the equator ) ( at ( ( several points ) ( in ( Earth history ) ) ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (JJ Geological) (NN evidence)) (VP (VBZ shows) (SBAR (IN that) (S (NP (JJ ice-albedo) (NN feedback)) (VP (VBD caused) (NP (NN sea) (NN ice) (NN advance)) (PP (TO to)) (PP (IN near) (NP (NP (DT the) (NN equator)) (PP (IN at) (NP (NP (JJ several) (NNS points)) (PP (IN in) (NP (NNP Earth) (NN history))))))))))) (. .)))
Geological evidence shows that ice-albedo feedback caused sea ice advance to near the equator at several points in Earth history.
(ROOT (S (SBAR (WHADVP (WRB How)) (S (NP (NN ice) (NNS cores)) (VP (VBP are) (ADJP (JJ important) (PP (TO to) (NP (NP (DT the) (NN study)) (PP (IN of) (NP (JJ geologic) (NN history))))))))) (VP (VBZ is) (ADVP (RBS best)) (VP (VBN described) (SBAR (IN as) (S (NP (PRP they)) (VP (VBP contain) (NP (NN evidence) (NN showing) (NNS changes)) (PP (IN in) (NP (NP (DT the) (JJ atmospheric) (NN composition)) (PP (IN over) (NP (NN time)))))))))) (. .)))