Ancient DNA Research: Growing Pains
Strobel, Gabrielle, Science News
When a promising, fast-moving field threatens to spin out of control, what do you do? Meet for a reality check.
That's exactly what scientists in the young area of ancient DNA research did recently. Instead of announcing success after success -- the usual stuff of scientific meetings -- the researchers pondered the many ways in which ancient specimens can lure experimenters down the wrong path.
In response to criticism voiced earlier by colleagues, Noreen Tuross called for "more analytical rigor to make this a credible field." Tuross is a biochemist with the Smithsonian Institution in Washington, D.C.
Ancient DNA comes from dead of extinct organisms 100 to millions of years old. If well preserved, such DNA can be recovered from ancient bone, animals frozen in Arctic soil, or creatures trapped in amber (SN: 10/24/92, p.280). Using a copying technique called polymerase chain reaction (PCR), scientists amplify -- reproduce in large quantities -- traces of such DNA and then decipher its genetic code.
The advantages of PCR -- its simplicity and low cost -- also present dangers, contents Tuross, since it attracts many people to the field. some of whom fail to scrutinize the condition of their samples with sensitive chemical methods. …