True - all birds are clearly related in some way, and our concepts of
"families" and "species" (and the other abstract entities such as orders)
vary with time and which school of taxonomic thought one subscribes to. If
all taxonomists agreed they would be out of a job and we would not need to
keep buying new field guides, or await eagerly the next "official" list to
see how the latest set of "splits" and "lumps" have changed our life list!
Hopefully none of this will put Peter off the rewarding hobby of actually
going out and looking at birds!
On 28/11/06, Philip Veerman <> wrote:
Dave,
I will provide a little correction to your comment about: "does not
necessarily indicate the species are related in any way". The family level
is an abstraction, as are all taxonomic units. All living things are related
in a way. We don't know if life started more than once. Even though many
taxonomic groups are easy to define, such as this is a bird or an insect,
etc. Actually when it comes to small dinosaurs, it gets pretty difficult to
define what is a bird.
Yes similarities may be convergent but going beyond that thought, they are
all related, it just depends how for back or how far down the tree you go.
Silvereyes are not classified in the same family as honeyeaters but are in
the same order, so have a common ancestor early in passerine history.
Penguins are not classified in the same order as honeyeaters but are in the
same class, so have a common ancestor early in bird history. People are not
classified in the same class as honeyeaters but are in the same phylum, so
have a common ancestor early in chordate history. Wattle trees are not
classified in the same kingdom as honeyeaters but are in the same set
comprising living things. Whilst most of our genetic material is the same as
that of apes, there is still some of our genetic systems are close to that
of plants and fungi etc.
Philip
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