![\"\"](\"http:\/\/junq.info\/wp-content\/uploads\/2019\/05\/Cloning_diagram_english.svg_-1024x674.png\")
According to a report from the Intergovernmental Science-Policy\nPlatform on Biodiversity and Ecosystem Services (IPBES) about one million\nspecies of an estimated number of around 8 million species (only counting\neukaryotes) on earth are currently endangered or threatened with loss of habitat.[6,7]\nIn the history of Earth extinction has mostly been a consequence of natural\ndisasters like climate change, volcanic eruptions, or meteorite impacts until\nhuman population started to expand.[8,9] The IPBES report demonstrates the present impact of human behaviour\non biodiversity and it seems that we are facing many more extinctions caused by\nanthropogenic reasons in the next decades. It has become a growing interest to\nnot only preserve existing species but also to revive those that have already\ndied out.<\/p>\n\n\n\n
One attempt is currently being made to revive Quaggas, a subspecies of\nthe living plain zebra that has died out in the 1880s (fig 2), by selective\nbreeding. Due to their close genetic relation some plain zebras that resemble\nthe characteristic pattern of the quaggas have been selected in the hope to one\nday give birth to a zebra that looks just like them and shows similar genetic\ninformation.[10,11,12]\n<\/p>\n\n\n\n More demanding is the CRISPR Cas9 method: the DNA that can be extracted\nfrom most fossils like the woolly mammoth could be much too old to produce a\nhealthy individuum. But their DNA might be partially recovered by replacing\nsome sequences in the DNA of their closest living relative, the elephant, with\nextracted mammoth DNA. The genome will not be the same as it was millions of\nyears ago and no one really knows how this will influence the livability of the\nanimals.[13]<\/p>\n\n\n\n But most of the extinct species do not have such close relatives\nanymore. Interspecies nuclear transfer like in Jurassic Park can be another\npossibility for de-extinction, that means to revive species that have gone\nextinct or are on the verge of extinction. The San Diego Zoo Institute for\nConservation Research maintains a large collection of cells and embryos called\nFrozen Zoo\u00ae.[14] By\nusing reproductive technologies they develop methods to prevent endangered\nspecies like the northern white rhino or the Przewalski horse from extinction\nor inbreeding.[ 15]\nThe first animal of an endangered species that was successfully cloned was a\ngaur (bos gaurus<\/em>), an Asian ox, in\n2001 by Advanced Cell Technology using genetic material from the San Diego Zoo.\nDNA from the skin cells of a male gaur were implanted into empty cow egg cells,\ngrown into blastomeres that were then transferred into the wombs of domestic\ncows. One of eight embryos developed to a full-grown calf. Unfortunately, after\nbeing born, the gaur did not live for more than two days. However, the cause of\ndeath is considered to be an infection and not the fact that it is a trans-species\nclone.[16] The second clone that was created with the\nvery same method had a higher life expectance. It was a banteng (bos\njavanicus<\/em>), another endangered Asian cattle. Also remarkable is, that the\nused fibroblasts were taken and frozen 25 years before, in 1978.[17] An attempt to clone a\nspecies that has already gone extinct, the Pyrenean ibex (capra pyrenaica\npyrenaica<\/em>) failed since the kid was born with a deformed lung.[18]<\/p>\n\n\n\n The fact that cloned cells do\nin principle develop to embryos and even prolific adult animals (like Dolly)\ngives hope that one day species that have recently been wiped out could come\nback to life. But besides the challenging and time-consuming scientific research\nthese plans also evoke a lot of critical questions in the society:<\/p>\n\n\n\n How is decided which species will\nbe revived and which stays extinct<\/em>?<\/p>\n\n\n\n It is clearly difficult to revive every species that we know has ever\nlived on this planet. There would just not be enough space and food and we\nmight soon experience another wave of mass extinction. Since DNA from fossils\nmight be too old, mammoths and dinosaurs are still out of question. This is shifting\nthe focus on species of the recent past. But how can we select which species\ncan live again and which won\u2019t? We surely must consider the preservation of\nstill existing species as a priority.<\/p>\n\n\n\n Where should they live?<\/em><\/p>\n\n\n\n If it is possible to clone many animals of one kind that can even mate,\nthere must be a safe and nourishing environment, most likely captivity. Who\nknows how an entire species that has been created in captivity will develop?\nAnd the knowledge about the behaviour and needs of most of those animals is\nvery little.[13]<\/p>\n\n\n\n Who is going to pay?<\/em><\/p>\n\n\n\n The scientist\u2019s motivation might surely be an idealistic one but\nsomehow all the research and maintenance must be financed. Innovations will\nalways attract temporizers that try to exploit it financially. Zoos and\nwildlife parks that exhibit animals are the lesser problem. Some worry that wealthy\npoachers and \u201cgourmets\u201d who don\u2019t withhold from hunting and eating endangered\nspecies now will just as much be attracted by the thought of getting hold of a\ncloned specimen. Paying to hunt an endangered species to support the protection\nfinancially is already practised in southern Africa and raises a lot of ethical\nissues.[19,20]<\/p>\n\n\n\n To see living \u201cfossils\u201d like dinosaurs, mammoths, dodos and all the\nothers is surely an exciting thought. But if mankind proceeds like this, in\njust a few decades there might be much less animals on earth than there are\nnow. Let\u2019s hope that combined common sense, technical progress, and less vanity\nwill lead to a preserved and healthy nature in our future.<\/p>\n\n\n\n \u2012Tatjana\nD\u00e4nzer<\/p>\n\n\n\n Read more:<\/p>\n\n\n\n [1] I. Wilmut<\/a>,\nA. E.\nSchnieke<\/a>, J. McWhir<\/a>,\nA. J. Kind<\/a>,\nK. H. S.\nCampbell<\/a>, Nature<\/em> 1997<\/strong>, 385<\/em>, 810\u2013813.<\/p>\n\n\n\n [2] M. Crichton, Jurassic Park<\/em>,\nAlfred A. Knopf, Inc., 1990.<\/p>\n\n\n\n [3] http:\/\/www.roslin.ac.uk\/publicInterest\/DollyFinalIilness.php<\/a>.<\/p>\n\n\n\n [4] S. L\u00fc, Y. Li, S. Gao, S. Liu, H. Wang, W. He, J. Zhou, Z. Liu, Y.\nZhang, Q. Lin, C. Duan, X. Yang, C. Wang, J.\nCell. Mol. Med<\/em>. 2010<\/strong>, 14<\/em>, 2771\u20122779.<\/p>\n\n\n\n [5] By en: converted to SVG by Belkorin, modified and translated by\nWikibob – derived from image drawn by \/ de: Quelle: Zeichner: Schorschski \/ Dr.\nJ\u00fcrgen Groth, with text translated, CC BY-SA 3.0, https:\/\/commons.wikimedia.org\/w\/index.php?curid=3080344<\/a>.<\/p>\n\n\n\n [6] https:\/\/www.ipbes.net\/news\/Media-Release-Global-Assessment<\/a>.<\/p>\n\n\n\n [7]\nC. Mora, D. P. Tittensor, S. Adl, A. g. B. Simpson, B. Worm, PLoS Biology<\/em>, 2011<\/strong>, 9<\/em>, 1\u20128.<\/p>\n\n\n\n [8] D. B. Weishampel, P. Dodson, H. Osm\u00f3lksa, The Dinosauria<\/em>, 2nd<\/sup> ed., University of California, 2004.<\/p>\n\n\n\n [9] D. P. G. Bond, P. B. Wignall, Geological Society of America\nSpecial Papers<\/em>, 2014<\/strong>, 505, <\/em>29\u201355.<\/em><\/p>\n\n\n\n [10] https:\/\/www.quaggaproject.org\/<\/a>.<\/p>\n\n\n\n [11] https:\/\/blog.nature.org\/science\/2014\/10\/13\/quagga-can-an-extinct-animal-be-bred-back-into-existence\/<\/a>.<\/p>\n\n\n\n [12] J. A. Leonard, N. Rohland, S. Glaberman, R. C. Fleischer, A. Caccone, M.\nHofreiter, Biol. <\/em>Lett<\/em>., 2005<\/strong>, 1<\/em>, 291\u2012295.<\/p>\n\n\n\n [13] B. Shapiro, Genome\nBiology<\/em>, 2015<\/strong>, 16<\/em>, 1\u20123.<\/p>\n\n\n\n [14] https:\/\/institute.sandiegozoo.org\/resources\/frozen-zoo%C2%AE<\/a>, [15]https:\/\/institute.sandiegozoo.org\/conservation-genetics<\/a>.<\/p>\n\n\n\n [16] https:\/\/web.archive.org\/web\/20080531142827\/http:\/\/www.advancedcell.com\/press-release\/advanced-cell-technology-inc-announced-that-the-first-cloned-endangered-animal-was-born-at-730-pm-on-monday-january-8-2001<\/a>.<\/p>\n\n\n\n [17] D. L. Janssen, A. L. Edwards, J. A. Koster, R. P. Lanza, O. A.\nRyder, Reproduction, Fertility and Development, <\/em>2004<\/strong>,<\/em> 16<\/em>, 224\u2012224.<\/p>\n\n\n\n [18] https:\/\/faculty.mtsac.edu\/cbriggs\/Bringing%20them%20back%20to%20life%202013.pdf<\/a>.<\/p>\n\n\n\n [19] http:\/\/www.bbc.com\/future\/story\/20180328-the-increasingly-realistic-prospect-of-extinct-animal-zoos<\/a>.<\/p>\n\n\n\n [20] https:\/\/www.pri.org\/stories\/2012-02-29\/hunters-shoot-and-pay-save-rhino<\/a>.<\/p>\n\n\n\n <\/p>\n\n\n\n <\/p>\n\n\n\n <\/p>\n","protected":false},"excerpt":{"rendered":" Just a few years before Dolly was born as the first surviving clone of a sheep in 1996, the movie Jurassic Park was launched, based on the same-named novel by Michael Crichton.[1,2] In this story scientists insert genetic material derived from fossils into amphibious eggs to bring all sorts of dinosaurs back to life. The… Read More »Will it be possible to revive species that have gone extinct?\ufeff<\/span><\/a><\/p>\n","protected":false},"author":12,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"neve_meta_sidebar":"","neve_meta_container":"","neve_meta_enable_content_width":"","neve_meta_content_width":0,"neve_meta_title_alignment":"","neve_meta_author_avatar":"","neve_post_elements_order":"","neve_meta_disable_header":"","neve_meta_disable_footer":"","neve_meta_disable_title":"","footnotes":""},"categories":[6],"tags":[],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/junq.info\/index.php?rest_route=\/wp\/v2\/posts\/3786"}],"collection":[{"href":"https:\/\/junq.info\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/junq.info\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/junq.info\/index.php?rest_route=\/wp\/v2\/users\/12"}],"replies":[{"embeddable":true,"href":"https:\/\/junq.info\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=3786"}],"version-history":[{"count":3,"href":"https:\/\/junq.info\/index.php?rest_route=\/wp\/v2\/posts\/3786\/revisions"}],"predecessor-version":[{"id":3791,"href":"https:\/\/junq.info\/index.php?rest_route=\/wp\/v2\/posts\/3786\/revisions\/3791"}],"wp:attachment":[{"href":"https:\/\/junq.info\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=3786"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/junq.info\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=3786"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/junq.info\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=3786"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}![\"\"](\"http:\/\/junq.info\/wp-content\/uploads\/2019\/05\/Quagga_bearbeitet-1024x768.png\")