Data presented by WINK et al. (1993, 1994) on inter- and intraspecific
mitochondrial genetic variation of gulls (Larus cachinnans, L. fuscus
, L. argentatus) and Cory's Shearwater (Calonectris diomeded) are rean
alyzed. It is shown that the data contradict or do not support several
of their main conclusions. In particular, cytochrome b sequence diver
gence between the gull species (0.69-2.04 %) is of the same magnitude
as between or even within some avian subspecies and mitochondrial gene
flow between them cannot be excluded with the small sample sizes avai
lable. The phylogenetic relationships among the three Larus species re
main unresolved (Fig.). Cory's Shearwaters show a high degree of diver
gence between mitochondrial lineages (1.51-1.87 %) even within subspec
ies as might be expected for a highly philopatric, colonially breeding
seabird. Some general requirements and limitations of the use of mtDN
A in the study of closely related species are outlined.