{"id":342,"date":"2014-10-31T10:54:17","date_gmt":"2014-10-31T10:54:17","guid":{"rendered":"http:\/\/uni.hi.is\/apalsson\/?p=342"},"modified":"2014-10-31T10:54:17","modified_gmt":"2014-10-31T10:54:17","slug":"icelandic-er-thad-rett-sem-dr-house-segir-i-einum-thaetti-ad-ef-dna-okkar-breytist-um-1-tha-verdum-vid-hofrungar","status":"publish","type":"post","link":"https:\/\/uni.hi.is\/apalsson\/IS\/2014\/10\/31\/icelandic-er-thad-rett-sem-dr-house-segir-i-einum-thaetti-ad-ef-dna-okkar-breytist-um-1-tha-verdum-vid-hofrungar\/","title":{"rendered":"Er \u00fea\u00f0 r\u00e9tt sem Dr. House segir \u00ed einum \u00fe\u00e6tti a\u00f0 ef DNA okkar breytist um 1% \u00fe\u00e1 ver\u00f0um vi\u00f0 h\u00f6frungar?"},"content":{"rendered":"

Arnar P\u00e1lsson. \u201eEr \u00fea\u00f0 r\u00e9tt sem Dr. House segir \u00ed einum \u00fe\u00e6tti a\u00f0 ef DNA okkar breytist um 1% \u00fe\u00e1 ver\u00f0um vi\u00f0 h\u00f6frungar? \u201c. V\u00edsindavefurinn<\/i> 9.12.2011. http:\/\/visindavefur.is\/?id=61036.<\/a><\/p>\n

Er \u00fea\u00f0 r\u00e9tt sem Dr. House segir \u00ed einum \u00fe\u00e6tti a\u00f0 ef DNA okkar breytist um 1% \u00fe\u00e1 ver\u00f0um vi\u00f0 h\u00f6frungar?<\/h1>\n

Sj\u00f3nvarpspers\u00f3nan Dr. House segir eitthva\u00f0 \u00e1 \u00feessa lei\u00f0 \u00ed einum \u00fe\u00e6tti: \u201eEf DNA okkar breytist um 1% \u00fe\u00e1 ver\u00f0um vi\u00f0 h\u00f6frungar.\u201c \u00deessi setning felur \u00ed s\u00e9r \u00fe\u00e1 hugmynd a\u00f0 menn og h\u00f6frungar s\u00e9u eins a\u00f0 upplagi. \u00dea\u00f0 er r\u00e9tt, menn (homo sapiens<\/em>) og h\u00f6frungar eru b\u00e6\u00f0i spend\u00fdr<\/a> me\u00f0 \u00e1\u00feekka grunnbyggingu og l\u00edkamsstarfsemi. Dr. House, e\u00f0a n\u00e1nar tilteki\u00f0 handritsh\u00f6fundar \u00fe\u00e1ttanna, fara hins vegar frj\u00e1lslega me\u00f0 nokkrar sta\u00f0reyndir. H\u00f6frungur<\/a> er nefnilega samheiti fyrir tugi tegunda sm\u00e1rra hvala \u00ed fj\u00f6lskyldunni (Delphinidae) sem skipa m\u00e1 \u00ed nokkrar \u00e6ttir. Innan \u00e6ttarinnar r\u00famast meira a\u00f0 segja h\u00e1hyrningar<\/a> (Orcinus orca<\/em>) og fimm a\u00f0rar tegundir sem \u00ed daglegu tali kallast hvalir, enda eru \u00fe\u00e6r mj\u00f6g st\u00f3rvaxnar. \u00c6ttartr\u00e9 \u00feessara tegunda hafa veri\u00f0 afhj\u00fapu\u00f0 me\u00f0 samanbur\u00f0i \u00e1 DNA<\/a>-r\u00f6\u00f0um, b\u00e6\u00f0i hvatbera og annarra gena<\/a>. Ni\u00f0urst\u00f6\u00f0urnar eru \u00fe\u00e6r a\u00f0 sumar tegundir h\u00f6frunga eru mj\u00f6g n\u00e1skyldar, en a\u00f0rar, eins og \u00e1rh\u00f6frungar \u00ed Amas\u00f3n, a\u00f0skildust fyrir meira en 20 millj\u00f3n \u00e1rum. \u00c1 svipu\u00f0um t\u00edma var uppi s\u00ed\u00f0asti sameiginlegi forfa\u00f0ir manna og Rhesusapa<\/a>. G\u00f6gnin s\u00fdna einnig a\u00f0 h\u00f6frungar og fl\u00f3\u00f0hestar<\/a> n\u00fat\u00edmans \u00e1ttu sameiginlegan forf\u00f6\u00f0ur fyrir um \u00fea\u00f0 bil 50 millj\u00f3n \u00e1rum. A\u00f0rir n\u00e1skyldustu \u00e6ttingjar h\u00f6frunga eru klaufd\u00fdr, sem innihalda me\u00f0al annars k\u00fdr og kindur.<\/p>\n

En hversu mikill munur er \u00fe\u00e1 \u00e1 erf\u00f0amengi manna og h\u00f6frunga? Munurinn milli manna og simpansa<\/a> er um \u00fea\u00f0 bil 1%, \u00feegar vi\u00f0 einskor\u00f0um okkur vi\u00f0 samanbur\u00f0 \u00e1 \u00feeim hlutum genanna sem mynda pr\u00f3t\u00edn<\/a>. A\u00f0rir hlutar erf\u00f0amengisins breytast hra\u00f0ar og eru \u00f3l\u00edkari milli tegunda. Einungis eitt erf\u00f0amengi h\u00f6frungs hefur veri\u00f0 ra\u00f0greint \u00ed heild, \u00fea\u00f0 er erf\u00f0amengi st\u00f6kkuls<\/a> (Tursiops truncatus<\/em>), en unni\u00f0 er a\u00f0 ra\u00f0greiningu nokkurra annara. Verkefni\u00f0 10K genomes <\/a> mi\u00f0ar a\u00f0 \u00fev\u00ed a\u00f0 ra\u00f0greina alls 10.000 hryggd\u00fdr. Mismunurinn \u00e1 genum manna og h\u00f6frunga er mun meiri en \u00fea\u00f0 1% sem Dr. House var lagt \u00ed munn. Sum gen eru \u00f3l\u00edk um 3%, \u00f6nnur 7% og enn \u00f6nnur mun \u00f3l\u00edkari. A\u00f0 auki hafa gen l\u00edka tapast e\u00f0a or\u00f0i\u00f0 til \u00ed \u00fer\u00f3unars\u00f6gu \u00feessara tegunda. Hluti af erf\u00f0amengi okkar er af sama mei\u00f0i og erf\u00f0amengi h\u00f6frunga, en vi\u00f0 h\u00f6fum einnig tapa\u00f0 nokkrum genum sem h\u00f6frungar bera enn \u00fe\u00e1 \u00ed s\u00e9r. A\u00f0 sama skapi h\u00f6ldum vi\u00f0 \u00ed nokkur gen sem \u00feeir hafa tapa\u00f0. Einfalt b\u00f3khald \u00e1 erf\u00f0amengjum manns og simpansa s\u00fdnir a\u00f0 okkur \u00e1skotnu\u00f0ust einnig nokkrir tugir gena \u00e1 undangengnum 3-5 millj\u00f3n \u00e1rum. Algengast er a\u00f0 sl\u00edkt ver\u00f0i \u00feegar eitt gen tv\u00f6faldast, en einnig ver\u00f0a til gen vi\u00f0 samruna tveggja gena og jafnvel framandi DNA-b\u00fata. Ranns\u00f3knir \u00e1 \u00fer\u00f3un h\u00f6frunga og annarra spend\u00fdra afhj\u00fapa a\u00f0 auki undarlegt mynstur. Hra\u00f0i \u00fer\u00f3unar (fj\u00f6ldi basabreytinga) er mismikill \u00e1 \u00f3l\u00edkum greinum \u00fer\u00f3unartr\u00e9sins. M\u00e6lingar s\u00fdna a\u00f0 me\u00f0al spend\u00fdra breytist hvatberalitningurinn um 1% \u00e1 hverjum millj\u00f3n \u00e1rum. \u00dea\u00f0 \u00fe\u00fd\u00f0ir a\u00f0 einn af hverjum 100 b\u00f6sum \u00ed DNA breytist \u00e1 \u00feessum t\u00edma. Hvalir og h\u00f6frungar eru hins vegar me\u00f0 mun l\u00e6gri \u00fer\u00f3unarhra\u00f0a \u00ed hvatberanum, um 0,25% \u00e1 hver millj\u00f3n \u00e1r. \u00c1st\u00e6\u00f0an er l\u00edklega hinn langi kynsl\u00f3\u00f0at\u00edmi hvala mi\u00f0a\u00f0 vi\u00f0 me\u00f0al spend\u00fdri\u00f0. Heimildir og \u00edtarefni:<\/strong><\/p>\n