April 13, 1984

Generalists and Specialists

Author Affiliations

Providence, RI

JAMA. 1984;251(14):1833-1834. doi:10.1001/jama.1984.03340380019009

To the Editor.—  Dr Davidson1 may be correct in his thoughts concerning the strengths of medical generalists, but his evolutionary analogies lend little credence to his argument.To suggest that fish are specialists is a gross misstatement. The teleost fishes make up without a doubt the greatest radiation of vertebrate evolution that exists today andprobably ever existed. The number of species and individuals occupying every conceivable habitat of fresh and marine waters and the diversity of this group far exceed those of all other vertebrates.2 While it is true that they spend their time under water, there is, after all, generally more water than land.It is also difficult to leave unchallenged the fanciful Lamarckian scenario of avian evolution apparently seriously offered as a caveat to subspecialization. The birds whose "beaks became so heavy that they were unable to fly" and then drowned in rising waters are entirely