- Email: [email protected]
DNA logic gates herald injectable computers
For daily news stories, visit www.NewScientist.com/news
DNA logic gates herald injectable computers AK>*?>PBAildf`d^qbpqe^q `lria`^oovlrq`^i`ri^qflkpfkpfab qeb_lave^sb_bbk`lkpqor`qba cloqebcfopqqfjb+Qebtloh _ofkdpqebmolpmb`qlcfkgb`q^_ib _fl`ljmrqbopmoldo^jjba qlq^odbqafpb^pbp^pqebv^ofpb+ ÎQeb_fl`ljmrqbotlriapbkpb _flj^ohbop^kafjjbaf^qbivob^`q _vobib^pfkd`lrkqbo*^dbkqpclo qebafpb^pb)Ïp^vpFq^j^oTfiikbo lcqebEb_obtRkfsbopfqvlc Gborp^ibj)Fpo^bi)telibaqebtloh+ Qebkbtildf`d^qbp^obclojba coljpeloqpqo^kaplcAK>^ka qebfo`ljmibjbkq^ovpqo^kap) tef`efk`lkgrk`qflktfqepljb pfjmibjlib`ri^oj^`efkbov jfjf`qebfobib`qolkf`bnrfs^ibkq+ Qtlpqo^kap^`q^pqebfkmrq7 b^`eobmobpbkqp^.tebkmobpbkq lo^-tebk^_pbkq+Qebobpmlkpb qlqebfomobpbk`blo^_pbk`b obmobpbkqpqeblrqmrq)tef`e `^k^ipl_b^.lo-+ Q^hbqebÎbu`irpfsbLOÏloULO ildf`d^qb+Fqmolar`bp^klrqmrq tebkbfqebolcqebqtlfkmrqpfp mobpbkq_rqklqtebk_lqe^ob mobpbkqlo_lqe^ob^_pbkq+Qlmrq qebAK>sbopflkqlqebqbpq)Tfiikbo ^kaefpqb^j^aabajlib`ribpql _lqeqeb`ljmibjbkq^ovpqo^kap qe^q`^rpbaqebjqlcirlobp`b tebkb^`et^pmobpbkqfk fpli^qflk)obmobpbkqfkd^ildf`^i.
^pqeblrqmrq+?rqtebk_lqetbob mobpbkq)qeb`ljmibjbkq^ov pqo^kap`lj_fkba^kanrbk`eba qebcirlobp`bk`b)obmobpbkqfkd^- lrqmrq%pbbaf^do^j&+ LkblcAK>`ljmrqfkdÑp ^as^kq^dbpfpqe^qfq^iiltp `^i`ri^qflkpql_b`^oofbalrqfk m^o^iibi)fcafccbobkqqvmbplcildf` d^qbp^obobmobpbkqba_vafccbobkq fkdobafbkqp+Qebqb^jqbpqba qefpmol`bpp_vqlppfkdqebULO fkdobafbkqpfkql^qbpqqr_b)^ilkd tfqeqelpbcloqtllqebod^qbp)ql molar`bqebcfopqcbtpqbmpfkslisba fk_fk^ov^aafqflk^kapr_qo^`qflk+ Qebqb^jt^p^ipl^_ibql`ob^qb ildf`d^qbpqe^q`^i`ri^qbfk pbnrbk`b+Qebqof`hebobfpqlj^hb
Early humans had taste for aquatic diet
to compete with other land hunters. The fossils lie alongside hundreds of stone tools that were probably used to butcher the animals (Proceeding of the National Academy of Sciences, DOI: 10.1073/pnas.1003181107). “It’s a massive amount of material,” says David Braun, an archaeologist at the University of Cape Town, South Africa, whose team began excavating the remains in 2004. There are no hominin bones at the site, making it difficult to determine who made the tools and ate the meat. The cache was found below a layer of volcanic ash from an eruption
A CACHE of turtles, crocodiles and catfish butchered some 2 million years ago has been uncovered near the eastern banks of Lake Turkana in Kenya. The remains, which are some of the earliest evidence of meat-eating in our ancestors, suggest that our early humans may have found it easier to get protein from aquatic animals than
qeblrqmrqcoljqebcfopqd^qb^kbt AK>pqofkdqe^q`^k_brpba^pqeb fkmrqclo^pb`lkad^qb^kapllk+ Pr`eÎ`^p`^afkdd^qbpÏ^iiltclo jlob`ljmibu`^i`ri^qflkp7qeb bkqfobpbqlcpqbmpobnrfobaclo ^aafqflk^kapr_qo^`qflk)clo bu^jmib)loqlabifsbo^jriqf*pqbm aordqob^qjbkq+ MobsflrpAK>*_^pba`ljmrqbop qbkabaqlpiltaltk^qb^`epqbm ^pqebAK>pqo^kaptbobrpbalkiv lk`b)^kapl_b`^jbabmibqbatfqe qfjb+Lkbpfdkfcf`^kq^as^k`b `i^fjba_vTfiikbo^kaefpqb^j fpqe^qqebfoAK>pqo^kapobcloj ^cqbob^`epqbm)^iiltfkdilkd pbnrbk`bplc`^i`ri^qflkpql_b `^oofbalrqb^pfivcloqebcfopqqfjb+ Bsbk^pfkdibildf`d^qb`lria e^sbrpbcrijbaf`^i^mmif`^qflkp) Tfiikbop^vp+Efpdolrm_rfiq^ka qbpqba^d^qbabpfdkbaqlobar`b qeb^`qfsfqvlcqeb_illa*`ilqqfkd
The logic of DNA computing The inputs to an XOR logic gate are two complementary strands of DNA. If one or the other is present, the gate fluoresces, indicating an output of 1. If both are present, they bind together preventing fluorescence, indicating an output of 0
A
B
D’
C’
A’
B’
D
C
OUTPUT
0
0
0
1
0
1
0
1
1
1
1
0
1.9 million years ago, but before a 2-million-year-old geomagnetic shift. That’s too early for Homo erectus. Braun says smaller, stockier hominins such as Homo habilis or even late australopithecines were responsible. The site represents our ancestors’ transition from herbivory to omnivory, Braun says. He suggests smaller early humans turned to hunting in water as they would have had trouble
“Aquatic animals may have provided nourishment that allowed our ancestors to boost their brain size”
bkwvjbqeolj_fk)tef`e`^kib^a ql_o^fka^j^dbcliiltfkd^eb^a fkgrov+Qebd^qb^`qp^p^ptfq`e qe^qfpqofddboba_vqebmobpbk`b lcqeolj_fk+M^oqlcqebd^qb `lkpfpqplc^AK>pqo^ka `lkkb`qbaql^jlib`ribqe^q _fkapqlqeolj_fk+Fcqeolj_fk fpmobpbkq)qefpjlib`ribfp
“A biocomputer in the bloodstream would control when and where medication is released” obib^pba)lqebotfpbfqpq^vp_lrka ^kafkboq+Pr`e^pj^oqaord`lria _bfkgb`qbafkqlqeb_illapqob^j fk^as^k`b^katlrialkivptfq`e lktebkkbbaba%K^qrob K^klqb`eklildv)ALF7.-+.-05, kk^kl+/-.-+55&+ >klqebomol_ibjtfqeb^oifbo AK>`ljmrqbopfpqe^qqebvrpb bkwvjbpqlj^kfmri^qbqebAK>) ^kaplcrk`qflklkivfk`boq^fk `ebjf`^ibksfolkjbkqpqe^q `^kklqb^pfiv_bobmolar`ba fkpfabqeb_lav+TfiikboÑpqb^jrpb AK>*ifhbjlib`ribpqlalqefpgl_+ Î?bfkdbkwvjb*cobb)fqe^p mlqbkqf^ifkcrqrobaf^dklpqf` ^kajbaf`^i^mmif`^qflkp)Ïp^vp ?bkkvDfilcqebTbfwj^kk FkpqfqrqblcP`fbk`bfkObelslq) Fpo^bi+Ebfpfjmobppbatfqe qebkbtd^qbpvpqbj_rq ob`ldkfpbpqe^qfqtfiiq^hbvb^op lcobpb^o`e^kaabsbilmjbkq ql_ofkdÎpj^oqaordpÏql jbaf`fkb+Kate McAlpine N
competing with carnivores on land. Aquatic animals may have also provided nourishment that allowed our ancestors to boost their brain size. Fish and reptiles are rich in fats and other nutrients that are needed to build up brain matter. “The discovery expands our understanding of the prowess of the earliest toolmakers,” says Richard Potts at the National Museum of Natural History in Washington, DC. But without evidence that early humans regularly ate marine animals, we can’t say that this was what boosted our brain size. Ewen Callaway N 5 June 2010 | NewScientist | 9
DNA logic gates herald injectable computers AK>*?>PBAildf`d^qbpqe^q `lria`^oovlrq`^i`ri^qflkpfkpfab qeb_lave^sb_bbk`lkpqor`qba cloqebcfopqqfjb+Qebtloh _ofkdpqebmolpmb`qlcfkgb`q^_ib _fl`ljmrqbopmoldo^jjba qlq^odbqafpb^pbp^pqebv^ofpb+ ÎQeb_fl`ljmrqbotlriapbkpb _flj^ohbop^kafjjbaf^qbivob^`q _vobib^pfkd`lrkqbo*^dbkqpclo qebafpb^pb)Ïp^vpFq^j^oTfiikbo lcqebEb_obtRkfsbopfqvlc Gborp^ibj)Fpo^bi)telibaqebtloh+ Qebkbtildf`d^qbp^obclojba coljpeloqpqo^kaplcAK>^ka qebfo`ljmibjbkq^ovpqo^kap) tef`efk`lkgrk`qflktfqepljb pfjmibjlib`ri^oj^`efkbov jfjf`qebfobib`qolkf`bnrfs^ibkq+ Qtlpqo^kap^`q^pqebfkmrq7 b^`eobmobpbkqp^.tebkmobpbkq lo^-tebk^_pbkq+Qebobpmlkpb qlqebfomobpbk`blo^_pbk`b obmobpbkqpqeblrqmrq)tef`e `^k^ipl_b^.lo-+ Q^hbqebÎbu`irpfsbLOÏloULO ildf`d^qb+Fqmolar`bp^klrqmrq tebkbfqebolcqebqtlfkmrqpfp mobpbkq_rqklqtebk_lqe^ob mobpbkqlo_lqe^ob^_pbkq+Qlmrq qebAK>sbopflkqlqebqbpq)Tfiikbo ^kaefpqb^j^aabajlib`ribpql _lqeqeb`ljmibjbkq^ovpqo^kap qe^q`^rpbaqebjqlcirlobp`b tebkb^`et^pmobpbkqfk fpli^qflk)obmobpbkqfkd^ildf`^i.
^pqeblrqmrq+?rqtebk_lqetbob mobpbkq)qeb`ljmibjbkq^ov pqo^kap`lj_fkba^kanrbk`eba qebcirlobp`bk`b)obmobpbkqfkd^- lrqmrq%pbbaf^do^j&+ LkblcAK>`ljmrqfkdÑp ^as^kq^dbpfpqe^qfq^iiltp `^i`ri^qflkpql_b`^oofbalrqfk m^o^iibi)fcafccbobkqqvmbplcildf` d^qbp^obobmobpbkqba_vafccbobkq fkdobafbkqp+Qebqb^jqbpqba qefpmol`bpp_vqlppfkdqebULO fkdobafbkqpfkql^qbpqqr_b)^ilkd tfqeqelpbcloqtllqebod^qbp)ql molar`bqebcfopqcbtpqbmpfkslisba fk_fk^ov^aafqflk^kapr_qo^`qflk+ Qebqb^jt^p^ipl^_ibql`ob^qb ildf`d^qbpqe^q`^i`ri^qbfk pbnrbk`b+Qebqof`hebobfpqlj^hb
Early humans had taste for aquatic diet
to compete with other land hunters. The fossils lie alongside hundreds of stone tools that were probably used to butcher the animals (Proceeding of the National Academy of Sciences, DOI: 10.1073/pnas.1003181107). “It’s a massive amount of material,” says David Braun, an archaeologist at the University of Cape Town, South Africa, whose team began excavating the remains in 2004. There are no hominin bones at the site, making it difficult to determine who made the tools and ate the meat. The cache was found below a layer of volcanic ash from an eruption
A CACHE of turtles, crocodiles and catfish butchered some 2 million years ago has been uncovered near the eastern banks of Lake Turkana in Kenya. The remains, which are some of the earliest evidence of meat-eating in our ancestors, suggest that our early humans may have found it easier to get protein from aquatic animals than
qeblrqmrqcoljqebcfopqd^qb^kbt AK>pqofkdqe^q`^k_brpba^pqeb fkmrqclo^pb`lkad^qb^kapllk+ Pr`eÎ`^p`^afkdd^qbpÏ^iiltclo jlob`ljmibu`^i`ri^qflkp7qeb bkqfobpbqlcpqbmpobnrfobaclo ^aafqflk^kapr_qo^`qflk)clo bu^jmib)loqlabifsbo^jriqf*pqbm aordqob^qjbkq+ MobsflrpAK>*_^pba`ljmrqbop qbkabaqlpiltaltk^qb^`epqbm ^pqebAK>pqo^kaptbobrpbalkiv lk`b)^kapl_b`^jbabmibqbatfqe qfjb+Lkbpfdkfcf`^kq^as^k`b `i^fjba_vTfiikbo^kaefpqb^j fpqe^qqebfoAK>pqo^kapobcloj ^cqbob^`epqbm)^iiltfkdilkd pbnrbk`bplc`^i`ri^qflkpql_b `^oofbalrqb^pfivcloqebcfopqqfjb+ Bsbk^pfkdibildf`d^qb`lria e^sbrpbcrijbaf`^i^mmif`^qflkp) Tfiikbop^vp+Efpdolrm_rfiq^ka qbpqba^d^qbabpfdkbaqlobar`b qeb^`qfsfqvlcqeb_illa*`ilqqfkd
The logic of DNA computing The inputs to an XOR logic gate are two complementary strands of DNA. If one or the other is present, the gate fluoresces, indicating an output of 1. If both are present, they bind together preventing fluorescence, indicating an output of 0
A
B
D’
C’
A’
B’
D
C
OUTPUT
0
0
0
1
0
1
0
1
1
1
1
0
1.9 million years ago, but before a 2-million-year-old geomagnetic shift. That’s too early for Homo erectus. Braun says smaller, stockier hominins such as Homo habilis or even late australopithecines were responsible. The site represents our ancestors’ transition from herbivory to omnivory, Braun says. He suggests smaller early humans turned to hunting in water as they would have had trouble
“Aquatic animals may have provided nourishment that allowed our ancestors to boost their brain size”
bkwvjbqeolj_fk)tef`e`^kib^a ql_o^fka^j^dbcliiltfkd^eb^a fkgrov+Qebd^qb^`qp^p^ptfq`e qe^qfpqofddboba_vqebmobpbk`b lcqeolj_fk+M^oqlcqebd^qb `lkpfpqplc^AK>pqo^ka `lkkb`qbaql^jlib`ribqe^q _fkapqlqeolj_fk+Fcqeolj_fk fpmobpbkq)qefpjlib`ribfp
“A biocomputer in the bloodstream would control when and where medication is released” obib^pba)lqebotfpbfqpq^vp_lrka ^kafkboq+Pr`e^pj^oqaord`lria _bfkgb`qbafkqlqeb_illapqob^j fk^as^k`b^katlrialkivptfq`e lktebkkbbaba%K^qrob K^klqb`eklildv)ALF7.-+.-05, kk^kl+/-.-+55&+ >klqebomol_ibjtfqeb^oifbo AK>`ljmrqbopfpqe^qqebvrpb bkwvjbpqlj^kfmri^qbqebAK>) ^kaplcrk`qflklkivfk`boq^fk `ebjf`^ibksfolkjbkqpqe^q `^kklqb^pfiv_bobmolar`ba fkpfabqeb_lav+TfiikboÑpqb^jrpb AK>*ifhbjlib`ribpqlalqefpgl_+ Î?bfkdbkwvjb*cobb)fqe^p mlqbkqf^ifkcrqrobaf^dklpqf` ^kajbaf`^i^mmif`^qflkp)Ïp^vp ?bkkvDfilcqebTbfwj^kk FkpqfqrqblcP`fbk`bfkObelslq) Fpo^bi+Ebfpfjmobppbatfqe qebkbtd^qbpvpqbj_rq ob`ldkfpbpqe^qfqtfiiq^hbvb^op lcobpb^o`e^kaabsbilmjbkq ql_ofkdÎpj^oqaordpÏql jbaf`fkb+Kate McAlpine N
competing with carnivores on land. Aquatic animals may have also provided nourishment that allowed our ancestors to boost their brain size. Fish and reptiles are rich in fats and other nutrients that are needed to build up brain matter. “The discovery expands our understanding of the prowess of the earliest toolmakers,” says Richard Potts at the National Museum of Natural History in Washington, DC. But without evidence that early humans regularly ate marine animals, we can’t say that this was what boosted our brain size. Ewen Callaway N 5 June 2010 | NewScientist | 9