SCIENCE BRIEFING
Times Staff and Wire Reports
Ever wonder why sharks get several rows of teeth and people only one?
Geneticists did, and their discovery could one day help adults grow new teeth when their own wear out.
A single gene appears to be in charge. When the scientists bred mice that lacked that gene, the rodents developed extra teeth next to their first molars -- backups like sharks grow -- University of Rochester scientists reported Thursday in the journal Science.
