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A
CKNOWLEDGMENTS
We are grateful to K. Summers for sharing his knowledge
on poison frogs and providing data on branch lengths, and
to J. Ahnesjo¨, M. Ha¨rlin, S. Merilaita, K. Summers, L. Trueb,
and J. Wallin for discussion and comments that helped im-
prove an earlier draft of the manuscript. The study was sup-
ported financially by The Swedish Research Council (grant
to AF), Va¨xjo¨ University and Kalmar University.
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