The species of interest to dr wirgin is the atlantic tomcod of the hudson river in upstate new york .
wirgin博士感兴趣的试验种群是位于纽约哈德逊河上游的大西洋小鳕。
Both hudson tomcod and new bedford killifish are able to tolerate levels of pcb far higher than those that would kill such fish in cleaner waters .
哈德森的鲟鱼和新贝德福德的鱼能够适应如此高的pcb含量,这已远远高于清水中的致死量,这是为什么呢?
The two missing links in the chain ( a phenylalanine and a leucine , for aficionados ) are encoded in the gene for ordinary tomcod ahr by six genetic " letters " that are missing from the dna found in pcb-resistant hudson tomcod .