\name{bird.orders}
\alias{bird.orders}
\title{Phylogeny of the Orders of Birds From Sibley and Ahlquist}
\description{
  This data set describes the phylogenetic relationships of the orders
  of birds as reported by Sibley and Ahlquist (1990). Sibley and
  Ahlquist inferred this phylogeny from an extensive number of DNA/DNA
  hybridization experiments. The ``tapestry'' reported by these two
  authors (more than 1000 species out of the ca. 9000 extant bird
  species) generated a lot of debates.

  The present tree is based on the relationships among orders. The
  branch lengths were calculated from the values of \eqn{\Delta
    T_{50}H}{Delta T50H} as found in Sibley and Ahlquist (1990,
  fig. 353).
}
\usage{
data(bird.orders)
}
\format{
  The data are stored as an object of class \code{"phylo"} which
  structure is described in the help page of the function
  \code{\link{read.tree}}.
}
\source{
  Sibley, C. G. and Ahlquist, J. E. (1990) Phylogeny and classification
  of birds: a study in molecular evolution. New Haven: Yale University Press.
}
\seealso{
  \code{\link{read.tree}}, \code{\link{bird.families}}
}
\examples{
data(bird.orders)
plot(bird.orders)
}
\keyword{datasets}