What do we pass on from gen­er­a­tion to gen­er­a­tion? A clear­sighted guide to hered­ity

The Guardian - Review - - Non-fiction - Katy Guest

Ge­neal­ogy is ap­par­ently the se­cond most searched sub­ject on the in­ter­net. Now that we can map our genes, we want to know where we come from. But hered­ity is not as sim­ple as the pass­ing on of traits from par­ents to off­spring: moth­ers can ac­quire cells from their own chil­dren; race “is not a fea­ture of the nat­u­ral world be­yond our so­cial ex­pe­ri­ence”; we can chop up DNA to re­place the bits we don’t like.

In this painstak­ingly re­searched book, Carl Zim­mer takes a long view of hered­ity. Sto­ries of how dis­cov­er­ies were made of­ten start with farm­ing and plants (Men­del’s peas) and con­tinue via unusual hu­mans (the Hab­s­burg jaw) be­fore be­ing proved or dis­proved by DNA se­quenc­ing, and then po­ten­tially rethought. Mini-bi­ogra­phies paint pow­er­ful pic­tures. Emma Wolver­ton, born in 1889, was sent away by her im­pov­er­ished fam­ily to the Vineland train­ing school for “fee­ble­minded chil­dren”. Henry God­dard, who ran the in­sti­tu­tion, traced her fam­ily tree and found ev­i­dence, he thought, that the men­tal de­fi­ciency was hered­i­tary. His pop­u­lar book The Kal­likak Fam­ily in­spired a young man called Adolf Hitler. The Nazis’ eu­gen­ics pro­gramme was based on re­search that turned out to be com­pletely false.

In 1910, in­tel­li­gence tests on im­mi­grants ar­riv­ing in New York were used to “prove” that “we are get­ting now the poor­est of each race”. One psy­chol­o­gist “claimed blacks were as in­tel­li­gent on av­er­age as a white per­son af­ter a lo­bot­omy”. It makes you won­der about some of to­day’s sci­en­tists who in­sist on large innate bi­o­log­i­cal dif­fer­ences be­tween men and women’s minds.

Some of the sci­ence around ge­netic dis­eases is a lit­tle hard to fol­low, and read­ers may find the story of Zim­mer’s own genome to be too much like navel gaz­ing – es­pe­cially when he re­veals that ge­neti­cists found “fifty-three species of bac­te­ria” in that ex­act spot. But the book of­fers clear in­sights into a fast­mov­ing area, and asks big ques­tions. Sci­en­tists can erad­i­cate dis­eases, al­ter DNA and change hu­man hered­ity. Should they? What if they get it wrong? by Carl Zim­mer, Pi­cador, £25

To buy She Has Her Mother’s Laugh for £22 go to guardian­book­shop.com.

She Has Her Mother’s Laugh: The Pow­ers, Perver­sions and Po­ten­tial of Hered­ity

Newspapers in English

Newspapers from UK

© PressReader. All rights reserved.