( But ( ( in ( ( the shadow ) ( of ( ( this debate ) ( about ( ( the cloning ) ( of ( humans ( or ( farm animals ) ) ) ) ) ) ) ) ) ) ( , ( ( researchers ( from ( several nations ) ) ) ( ( have ( been ( actively ( ( collecting ( tissue ( from ( ( the remains ) ( of ( ( the ( woolly mammoth ) ) ( in preparation ) ) ) ) ) ) ) ( for ( an ( attempt ( to ( ( ( bring ( the beast ) ) back ) ( from ( ( ( ten thousand ) years ) ( of extinction ) ) ) ) ) ) ) ) ) ) ) ) . ) ) ) ) )
(ROOT (S (CC But) (PP (IN in) (NP (NP (DT the) (NN shadow)) (PP (IN of) (NP (NP (DT this) (NN debate)) (PP (IN about) (NP (NP (DT the) (NN cloning)) (PP (IN of) (NP (NNS humans) (CC or) (NN farm) (NNS animals))))))))) (, ,) (NP (NP (NNS researchers)) (PP (IN from) (NP (JJ several) (NNS nations)))) (VP (VBP have) (VP (VBN been) (VP (ADVP (RB actively)) (VBG collecting) (NP (NP (NN tissue)) (PP (IN from) (NP (NP (DT the) (NNS remains)) (PP (IN of) (NP (NP (DT the) (JJ woolly) (NN mammoth)) (PP (IN in) (NP (NN preparation)))))))) (PP (IN for) (NP (DT an) (NN attempt) (S (VP (TO to) (VP (VB bring) (NP (DT the) (NN beast)) (PRT (RP back)) (PP (IN from) (NP (NP (QP (CD ten) (CD thousand)) (NNS years)) (PP (IN of) (NP (NN extinction))))))))))))) (. .)))
But in the shadow of this debate about the cloning of humans or farm animals, researchers from several nations have been actively collecting tissue from the remains of the woolly mammoth in preparation for an attempt to bring the beast back from ten thousand years of extinction.
(ROOT (S (NP (JJ Woolly) (NNS mammoths)) (VP (VBD began) (S (VP (TO to) (VP (VB go) (NP (NP (ADJP (JJ extinct)) (NNS thousands)) (PP (IN of) (NP (NNS years)))) (ADVP (RB ago) (PP (IN because) (PP (IN of) (S (VP (VBG hunting) (PP (IN by) (NP (NNS humans)))))))))))) (. .)))
Woolly mammoths began to go extinct thousands of years ago because of hunting by humans.