Ne­an­derthal book de­tails sci­en­tific process

Winnipeg Free Press - Section G - - BOOKS - Re­viewed by Paul Klassen

Bis Pääbo’s pro­fes­sional au­to­bi­og­ra­phy, and it pro­vides a win­dow into how sci­en­tists work at care­fully gath­er­ing ev­i­dence — in this case, across con­ti­nents and decades. While in­ter­est­ing, it is fairly dense, and some­times even metic­u­lous in de­tail. Per­haps Dr. Pääbo him­self is the “Ne­an­derthal man” of the ti­tle. His ca­reer pro­gressed along­side the in­ven­tion and ex­po­nen­tial growth of ge­netic se­quenc­ing tech­nol­ogy, and early on he dreamed of se­quenc­ing an­cient DNA. This fas­ci­na­tion was strong enough that he left med­i­cal school to pur­sue re­search in this nascent field al­most 30 years ago. Some of the first tar­gets were re­cently ex­tinct crea­tures like the quagga and the Tas­ma­nian wolf, as well as Egyp­tian mum­mies. In the early days, it wasn’t pos­si­ble to read much of a genome. Pääbo and other sci­en­tists could con­firm DNA was present, and used painstak­ing meth­ods to read small seg­ments. In­evitably, there were com­peti­tors who made sen­sa­tional claims about ex­tract­ing DNA from fos­sils mil­lions of years old, in­clud­ing, fa­mously, from in­sects trapped in am­ber. But Pääbo had al­ready no­ticed that even his sev­eral-thou­sand year-old sam­ples were hard to study due to the in­evitable break­down of ge­netic ma­te­rial. Sure enough, it soon turned out that the “dino-DNA” was re­ally just con­tam­i­na­tion. Even a speck of dust float­ing in the lab may be a flake of some­one’s skin, full of mod­ern DNA. It’s just not pos­si­ble to re­cover DNA from the di­nosaurs. Frowny­face emoti­con, full stop. The rig­or­ous check­ing, re­view­ing, and dou­ble-check­ing that sci­en­tists have to do is il­lus­trated very well in Ne­an­derthal Man. Rather than rush to a sen­sa­tional head­line, Pääbo and his team sought in­de­pen­dent con­fir­ma­tion of their find­ings, and sub­mit­ted their pa­pers to peer re­view. Sev­eral times, this spared them from em­bar­rass­ing re­trac­tions. The in­ner work­ings of academia make for some dry sec­tions, but the ac­qui­si­tion of pre­cious Ne­an­derthal bones turns out to be one of the most in­trigu­ing parts of the story. With com­peti­tors pre­pared to “go to Rus­sia with a pil­low­case and an en­ve­lope full of eu­ros,” Pääbo went to Croa­tia. Ob­tain­ing well­p­re­served Ne­an­derthal spec­i­mens re­quired pa­tience, per­sis­tence, and friends in high places. As the re­searchers gath­ered the DNA-filled bones they needed, genome se­quenc­ing tech­nol­ogy came of age, and ma­chines soon be­gan spit­ting out mil­lions of As, Gs, Cs and Ts that lined up closely with the hu­man genome — but not com­pletely. Ul­ti­mately, all this ef­fort was able to an­swer some big ques­tions about the hu­man story. Did we “mod­ern hu­mans” have sex with Ne­an­derthals and have their ba­bies? Well, the 2.7 per cent (on aver­age) of Ne­an­derthal DNA in most of us had to get there some­how. The Ne­an­derthal genome lives on in most of the hu­mans of to­day, for the most part be­cause it is (barely) present in mod­ern­day Africans. This sup­ports the hy­poth­e­sis that a wave of people left Africa, mixed and min­gled with Ne­an­derthals in the Mid­dle East, and then spread out across the globe. Those are the head­lines, but Ne­an­derthal Man is re­ally about the story be­hind the head­lines, which is the story of sci­ence it­self and the people who work through the years, mostly un­cel­e­brated, to un­cover more about who we are. E warned: in spite of the ti­tle, this book isn’t re­ally about Ne­an­derthal man. If you’ve ever won­dered what Ne­an­derthals might have looked like, where and how they lived, or what clothes, tools and cul­ture they pos­sessed, you will still be won­der­ing at the end of this sci­en­tific mem­oir. Rather, look to the sub­ti­tle — this is a book about find­ing, de­cod­ing and study­ing an­cient genomes. Svante Pääbo, a Swedish bi­ol­o­gist, is one of the pi­o­neers of pa­le­o­ge­net­ics, the study of an­cient life through an­cient DNA, and he is best-known for se­quenc­ing the Ne­an­derthal genome in 2010. Ne­an­derthal Man

Paul Klassen is a Win­nipeg en­gi­neer.

Ne­an­derthal Man: In Search of Lost

Genomes

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