Controversial science
At his talk, Palumbi will explain how recent advances in genetics have helped revolutionize whale research while sometimes sparking controversy.
The most recent firestorm began in July 2003, when the journal Science published a study on humpback, fin and minke whale populations co-authored by Palumbi and graduate student Joe Roman. Using DNA analysis, Palumbi and Roman concluded that the worldwide population of humpbacks, now estimated at 20,000, might have been as been as high as 1.5 million before commercial whaling took off in the 1800s. That figure is more than 10 times bigger than the widely accepted historical estimate of 100,000 humpbacks, which is based on 19th-century whaling records.
In their study, Palumbi and Roman analyzed maternally inherited mitochondrial DNA samples from hundreds of humpback whales. They discovered that the DNA sequence in a gene called ''D loop'' varied widely among individual whales.
''A small population tends to weed out all of its genetic differences through inbreeding,'' Palumbi noted. ''A large population should have a lot more genetic variation. Our study shows that humpback whales today actually have about 10 times more genetic variation than would be expected from previous estimates of their populations.''
This finding caused an uproar among researchers who have long relied on whaling records to calculate historical populations. Some critics said that Palumbi's estimate of 1.5 million humpbacks was not ''remotely realistic,'' while others took strong exception to his assertion that whalers' logbooks might be incomplete and unreliable.
The Science study also sent shockwaves through the International Whaling Commission (IWC), a consortium of 51 countries that re
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Contact: Mark Shwartz
mshwartz@stanford.edu
650-723-9296
Stanford University
19-Feb-2005